|August 10, 2007|
|Nutrition Research Alert|
|Emerging Technologies :: R&D Trends :: Technology Innovation :: Strategic Analysis|
ASSESSING CARDIOVASCULAR DISEASE RISK
FACTORS IN CHILDREN AND ADOLESCENTS
Studies have shown that abdominal obesity, as measured by the waist circumference or related indexes such as the waist-to-hip ratio, is associated with the subsequent development of type 2 diabetes and ischemic heart disease, as well as with risk factors for cardiovascular disease (CVD). Furthermore, despite the relatively low amount of intraabdominal fat among children, several indexes of abdominal obesity are associated with CVD risk factors among children and adolescents.
Several studies of children and adults have concluded that this ratio is more strongly associated with CVD risk factors than is BMI. In addition, waist-to-height ratio may be simpler to use. For example, because waist-to-height ratio is only weakly associated with age, measures among children do not have to be expressed relative to their sex and age peers [by using z scores] as do measures of BMI.
A recent investigation compares the relation of BMI and waist-to-height ratio to measures of lipids, fasting insulin, and blood pressure among 5 to 17 year-olds (n = 2498) in the Bogalusa Heart Study. Additionally, investigators examined the abilities of these 2 indexes to correctly identify children with adverse risk factors. The Bogalusa (Louisiana) Heart Study is a community-based study of CVD risk factors in early life. Seven cross-sectional examinations of school children were conducted since 1973, and the current analyses are based on the 1993-1994 examination.
Height and weight were measured and BMI was calculated. BMI z scores were calculated from the 2000 Centers for Disease Control and Prevention (CDC) Growth Charts to account for the differences in BMIs by sex and age. These growth charts express the BMIs of children in the current study relative to their sex and age peers in the United States between 1963 and 1980; the calculated z scores are termed "BMI for age." Overweight is defined as a BMI-for-age z score = 1.645 (corresponding to the 95th percentile of normally distributed data) of these growth charts.
Waist circumference was measured. Concentrations of serum total cholesterol and triacylglycerols and insulin were measured. Sitting systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured 6 times. Because measures of lipids, insulin, and blood pressures vary substantially by sex and age, researchers defined adverse measures in relation to a childs sex and age peers in the Bogalusa Study sample. The risk factor sum was used as a summary measure of the 6 risk factors and was derived by combining adjusted measures of triacylglycerols, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, fasting insulin, SBP, and DBP.
As assessed by the ability of the 2 indexes to 1) account for the variability in each risk factor and 2) correctly identify children with adverse values, the predictive abilities of the BMI-fir-age z score and waist-to-height ratio were similar. Waist-to-height ratio was slightly better in predicting concentrations of total-to-HDL cholesterol ratio and LDL cholesterol, but BMI was slightly better in identifying children with high SBP in predicting measures of fasting insulin and systolic and diastolic blood pressures. On the basis of an overall index of the 6 risk factors, no difference was observed in the predictive abilities of BMI-for-age and waist-to-height ratio. This similarity likely results from the high intercorrelation between the 2 indexes.
BMI-for-age and waist-to-height ratio do not differ in their abilities to identify children with adverse risk factors. Although waist-to-height ratio may be preferred due to its simplicity, additional longitudinal data are needed to examine its relation to disease.
D. Freedman, H. Kahn, Z. Mei. Relation of body mass index and waist-to-height ratio to cardiovascular disease risk factors in children and adolescents: the Bogalusa Heart Study. Am J Clin Nutr;86;33-40 (July, 2007). [Correspondence: DS Freedman, CDC K-26, 4770 Buford Highway, Atlanta GA 30341. E-mail: email@example.com].
Exposure to large portions of energy-dense foods may contribute to childhood obesity by promoting excessive energy intake. Secular trends reveal increases in the average size of food portions consumed by children both in and outside the home from the late 1970s through the 1990s. Across studies, children did not compensate for increased energy intake from large food portions by reducing the consumption of other foods. These findings suggest that large food portions can promote increased energy intake. However, evidence regarding the effects of energy density (ED; energy/g) on childrens intake is less clear.
An investigation was performed with the aim to test the effects of entrée portion size and ED on satiation in preschool children. The participants were 53 ethnically diverse 5 to 6 year-old children (28 girls, 25 boys) and their mothers. On an average, mothers were in their mid 30s, were overweight, and were well-educated. Children were, on an average, of normal weight; 6 of 53 were overweight (BMI = 95th percentile).
A 2 X 2 within-subject factorial design was used to evaluate effects of portion size and ED on satiation. Each child was seen in 4 conditions differing only in the portion size (250 g or 500 g) and ED (1.3 kcal/g or 1.8 kcal/g) of a macaroni and cheese entrée served at a dinner meal. The reference entrée portion size was doubled for the large portion condition. The ED of the dinner entrée varied by 40% across conditions via manipulations in fat and water content. Fixed portions of other foods and beverages were offered at each meal. Each condition was spaced 1 week apart. Children ate in small groups of 3 to 4. Weighed intake methods were used to assess childrens food intake. Childrens preferences for the entrée and for other foods offered were measured by using a tasting procedure. Height and weight measurements were obtained from children and their mothers. Mothers also provided family demographic information.
Effects of portion size (P < 0.0001) and ED (P < 0.0001) on entrée energy intake were independent but additive. Energy intake from other foods at the meal did not vary across conditions. Compared with the reference portion size and ED condition, children consumed 76% more energy from the entrée and 34% moiré energy at the meal when served the larger, more energy-dense entrée. Effects did not vary by sex, age, entrée preference, or BMI z scores.
These findings provide new evidence that portion size and ED act additively to promote energy intake at meals in preschool-aged children.
J. Fisher, Y. Liu, L. Birch, et al. Effects of portion size and energy density on young childrens intake at a meal. Am J Clin Nutr;86:174-179 (July, 2007). [Correspondence: JO Fisher, USDA Childrens Nutrition Research Center, 1100 Bates Street, Suite 4004, Houston TX, 70030. E-mail: firstname.lastname@example.org.]
The prevalence of childhood obesity is on the rise worldwide, and the dietary patterns contributing to this increase are poorly understood. One dietary factor that has received less attention in the study of pediatric obesity is dietary energy density (ED), which is defined as calories per weight of food (kcal/g). It is suggested that under laboratory conditions, as well as in the free-living environment, adults regulate the amount of food they consume (by weight or volume) to a greater extent than the calories they consume.
Studies of children that experimentally altered the ED of foods tested childrens ability to compensate for energy. Energy compensation refers to the adjustment of food intake during an ad libitum meal in response to variations in the ED from a preload. Laboratory protocols have the advantage of assessing childrens food intake objectively. However, they generally limit the food choices, which, in turn, may create conditions that alter the subjects habitual eating behavior. It is important to assess childrens eating behavior in relation to dietary ED under free-living conditions when they have access to an ample array of foods that vary in ED.
Specific questions regarding ED and children arise. Do children regulate the number of calories they consume on a daily basis, or do they regulate the amount or the volume of food they ingest, as the data in adults suggest? Also, are there differences in intake regulation between children who are born with a different predisposition to obesity and, if so, how does this affect their ability to compensate?
The first aim of a recent investigation was to examine the interrelation between daily ED, daily food intake, and daily energy intake among children born at high or low risk of obesity. The second aim was to examine childrens daily food intake in relation to their predicted daily food intake for a given level of daily ED and to assess potential changes in childrens compensation ability over time (from ages 3 to 6 years). All analyses were completed including or excluding all beverages.
Subjects were children born at high risk (n = 22) or low risk (n = 27) of obesity on the basis of maternal prepregnancy BMI. Daily ED, food intake, and energy intake were assessed from 3-day food records that either included or excluded beverages. Intake regulation was explored by relating childrens daily food and energy intakes to ED and, more importantly, by examining residual scores derived by regressing daily food intake on ED.
For both risk groups, daily food intake was inversely correlated with ED (P < 0.05), whereas daily energy intake was not significantly correlated with ED at most ages (P > 0.05). In analyses that excluded beverages, mean residual scores significantly increased from 3 to 6 years of age in high-risk children, which indicates relative overconsumption, but decreased in low-risk children, which indicates relative underconsumption (risk group x time interaction, P = 0.005).
In this investigation, children adjusted their daily food intake in relation to ED, which suggests caloric compensation under free-living conditions. Compensation ability may deteriorate with age in a manner that favors relative food overconsumption among obesity-prone children.
T. Kral, A. Stunkard, R. Berkowitz, et al. Daily food intake in relation to dietary energy density in the free-living environment: a prospective analysis of children born at different risk of obesity. Am J Clin Nutr;86:41-47 (July, 2007). [Correspondence: TVE Kral, Center for Weight and Eating Disorders, University of Pennsylvania School of Medicine, 3535 Market Street, 3rd Floor, Philadelphia, PA 19104. E-mail: email@example.com.]
Atherosclerosis is a major cause of coronary heart disease (CHD) and ischemic stroke. The progression of plaque formation and calcium deposition is associated with the accumulation of macrophages, smooth muscle cells, fibrosis, necrosis, and lipids in the arteries. Coronary artery calcification (CAC) is a risk marker for atherosclerosis and is positively associated with CHD and CVD events.
The established risk factors for coronary calcification are the same as those for clinical CVD: male sex, age, BMI, elevated blood pressure, diabetes mellitus, cigarette smoking, and LDL and HDL cholesterol. Abdominal obesity is also a significant risk factor for atherosclerosis. Excessive accumulation of visceral fat is associated with insulin resistance and compensatory hyperinsulinemia, which contributes to atherosclerotic progression.
Researchers investigated the relation of visceral fat measured by waist girth or waist-hip ratio (WHR) to CAC in young African American and white men and women from the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The CARDIA study is a population-based cohort study designed to investigate the causes of atherosclerosis in a young biracial population. Men and women aged 18 to 30 years were included in the study. The participants were examined 5 times over a 15 year period. The current investigation is based on 3043 subjects who underwent a coronary artery scan at the year 15 examination to determine the presence or absence of calcium deposits in the arteries.
Body height and weight were measured. Waist and hip girth was also measured. Seated blood pressure was obtained. Blood was analyzed for total cholesterol, HDL cholesterol, triacylglycerols, and fasting insulin. CAC was determined by using computed tomography. Cigarette smoking, alcohol intake, physical activity, and educational level were assessed by means of standardized questionnaires.
After adjustment for age, sex, race, clinical center, physical activity, cigarette smoking, education, and alcohol intake, baseline waist girth and WR were directly associated with a higher prevalence of CAC 15 years later (P for trend < 0.001 for both). The odds ratios (ORs) for CAC in the highest versus lowest tertiles of waist girth and WHR were 1.9 (95% CI: 1.36, 2.65) and 1.7 (1.23, 2.41), respectively. Waist girth and WHR at year 10 and waist girth at year 15 similarly predicted CAC. These associations persisted after additional adjustment for SBP, fasting insulin concentrations, diabetes, and antihypertensive medication use but became nonsignficant after additional adjustment for blood lipids.
Abdominal obesity measured by waist girth or WHR is associated with early atherosclerosis as measured by the presence of CAC in African American and white young adults. This is consistent with an involvement of visceral fat in the occurrence of coronary artery calcium in young adults.
C. Lee, D. Jacobs, P. Schreiner, et al. Abdominal obesity and coronary artery calcification in young adults: the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Am J Clin Nutr;86:48-54 (July, 2007). [Correspondence: C-D Lee, Department of Exercise and Wellness, Arizona State University, 7350 East Unity Avenue, Mesa, AZ 85212. E-mail: firstname.lastname@example.org].
The introduction of corn sweeteners into the US food supply is said to have contributed to the current obesity epidemic. High-fructose corn syrup (HFCS) began to replace sucrose in soft drinks at approximately the same time that obesity rates in the United States began their sharp increase. However, temporal parallels between HFCS consumption patterns and body weight trends are not sufficient to show causality.
One of the criteria for establishing causality in evidence-based medicine is a biologically plausible mechanism. Attempts to establish a causal link between soft drink consumption and rising obesity rates have therefore relied on the notion that caloric beverages in general, and HFCS-sweetened beverages in particular, lack satiating power. The metabolic and endocrinologic processes associated with the ingestion of free fructose have featured prominently in arguments that HFCS-sweetened beverages are the principal culprit in the obesity epidemic.s
However, satiety-related arguments based on the ingestion of pure fructose or fructose-rich stimuli may not apply to sweetened beverages, given that the 2 most common forms of HFCS--HFCS 55 and HFCS 42--contain 55% and 42% free fructose, respectively, and the remainder is free glucose.
An investigation directly tested the hypothesis that HFCS-sweetened carbonated soft drinks differ significantly from sucrose-sweetened soft drinks and from low-fat milk in their effect on satiety. Aiming to approximate naturalistic conditions of soft drink use, the researchers compared the effect of commercially available cola beverages, sweetened with sucrose or with 2 types of HFCS (HFCS 42 and HFCS 55), on hunger, satiety, and energy intakes (EIs) at the test meal. Because so much has been made of the metabolic differences between free fructose and fructose bound within disaccharide sucrose molecules, investigators sent samples of the sucrose-sweetened beverage to be analyzed for free sugars content at the time of the experiment.
The study followed a repeated-measures within-subject design, in which each participant returned for 6 separate test sessions. The order of presentation of the 5 preloads and the no-beverage condition was counterbalanced. The same lunch foods were offered on all 6 testing occasions. The magnitude of the energy manipulation (0 or 215 kcal) was based on a review of previous studies in this area.
The 5 beverages were cola sweetened with HFCS 42, cola sweetened with HFCS 55, cola sweetened with sucrose, cola sweetened with aspartame, and 1%-fat milk. All preload beverages with the exception of the diet cola were isoenergetic and of comparable sweetness, but they differed in sugar composition. Particpants used computerized, semi-anchored visual analogue scales (VASs) to rate their hunger, fullness, thirst, nausea, and desire to eat. A lunch meal was provided and was consistent in calories, including a variety of foods, both savory and sweet. Participants were told that they could have as much or as little as they would like of any food or water and that they could request unlimited additional portions. All foods and water were weighed at the time of serving. Plate waste was collected and weighed by the experimenters.
Researchers found no differences between sucrose- and HFCS-sweetened colas in perceived sweetness, hunger, and satiety profiles, or EI at lunch. The 4-caloric beverages tended to partially suppress EI at lunch, whereas the no-beverage and diet beverage conditions did not; the effect was significant (P < 0.05) only for 1%-fat milk. EI in the diet cola and the no-beverage conditions did not differ significantly.
There was no evidence to suggest that commercial cola beverages sweetened with either sucrose or HFCS have significantly different effects on hunger, satiety, or short-term energy intakes.
P. Monsivais, M. Perrigue, A. Drewnowski. Sugars and satiety: does the type of sweetener make a difference? Am J Clin Nutr;86:116-123 (July, 2007). [Correspondence: A Drewnowski, 305 Raitt Hall, Box 353410, University of Washington, Seattle, WA 98195. E-mail: email@example.com].
The physiologic response to stress is coordinated by the pituitary gland, which secretes trophic hormones in response to central nervous system input from the hypothalamus. The essential adrenocorticotrophic hormone (ACTH) secreted by the pituitary gland stimulates adrenal glands to synthesize and secrete cortisol. ACTH also causes vitamin C loss from adrenals. Adrenal glands are rich in vitamin C. For these reasons, vitamin C and stress in humans have long been associated, despite a lack of direct evidence for such a link.
Humans, unlike most animals, cannot synthesize vitamin C and instead must obtain it from diet. Healthy humans consuming 200 mg to 300 mg vitamin C per day, an amount obtainable from foods such as fruit and vegetables in which the vitamin is abundant, maintain steady-state fasting plasma concentrations. Tightly controlled plasma vitamin c concentrations are exceeded transiently with oral doses of = 1 gram in amounts obtainable only from supplements and not from foods. The observed tight control of vitamin C plasma and tissue concentrations is mediated by gastrointestinal absorption, cellular transport, and renal reabsorption and excretion.
Scientists hypothesized that the adrenal glands secrete vitamin C after simulated stress and that tight control of plasma vitamin C concentrations would permit intraadrenal vitamin C concentrations to be far higher than those in peripheral veins. To test this, researchers studied patients with hyperaldosteronism who underwent adrenal vein sampling for specific diagnosis. In these patients, they measured adrenal and peripheral vein vitamin C and cortisol concentrations after ACTH administration.
Adrenal vein vitamin C concentrations increased in all cases and reached a peak of 176 ± 71 micromol/L at 1 to 4 min, whereas the corresponding peripheral vein vitamin C concentrations were 35 ± 15 micromol/L (P < 0.0001). Mean adrenal vein vitamin C increased from 39 ± 15 micromol/L at 0 min, rose to 162 ± 101 micromol/L at 2 min, and returned to 55 ± 16 micromol/L at 15 min. Adrenal vein vitamin C release preceded the release of adrenal vein cortisol, which increased from 1923 ± 2806 nmol/L at 0 min to 27 191 ± 16161 nmol/L at 15 min (P < 0.0001). Peripheral plasma cortisol increased from 250 ± 119 nmol/L at 0 min to 506 ± 189 nmol/L at 15 min (P < 0.0001).
Researchers conclude that ACTH stimulation increases adrenal vein but not peripheral vein vitamin C concentrations. This data is the first in humans showing that adrenal vitamin C paracrine secretion is part of the stress response.
S Padayatty, J. Doppman, R. Chang, et al. Human adrenal glands secrete vitamin C in response to adrenocorticotrophic hormone. Am J Clin Nutr;86:145-149 (July, 2007). [Correspondence: M Levine, Molecular and Clinical Nutrition Section, Building 10, Room 4D52-MSC 1372, National Institutes of Health, Bethesda, MD 20892-1472. E-mail: firstname.lastname@example.org.]
It is well recognized that adequate stores of vitamin D are crucial for musculoskeletal health. The best indicator of vitamin D stores is the serum concentration of calcidiol, or 25-hydroxyvitaminD [25(OH)D]. When circulating 25(OH)D concentrations are inadequate, a state known as hypovitaminosis D, intestinal calcium absorption and bone mineralization are impaired. More severe deficits in 25(OH)D lead to clinical myopathy, osteomalacia in adults, and rickets in children. In addition to its musculoskeletal effects, vitamin D is important for immune function, and hypovitaminosis D may contribute to varied diseases, such as hypertension, cancer, multiple sclerosis, and type 1 diabetes.
Hypovitaminosis D remains an underrecognized problem in the general population and is poorly defined in children. Of substantial concern, given the current obesity epidemic, is that obesity in children was also shown to be associated with decreased 25(OH)D concentrations; however, these prior studies determined obesity by using BMI rather than a more direct estimate of body fat mass.
The aims of a recent investigation were to determine 1) the prevalence of serum (OH)D concentrations < 30 ng/mL--a recognized indicator of hyppovitaminosis D in adults and of more severe deficits of 25(OH)D in children and adolescents--and 2) the factors associated with reduced 25(OH)D concentrations. A cross-sectional study of skeletal development in healthy children aged 6 to 21 years from the Philadelphia, PA, area was conduced. Blood samples were obtained in a subset of the participants. For inclusion, children had to have a reported height, weight, and BMI within the 5th to 95th percentile.
A nonfasting blood sample was drawn to determine serum concentrations of 25(OH)D, 1,25(OH)2D, parathyroid hormone (PTH), and bone-specific alkaline phosphatase (BSAP). For purposes of the analysis, researchers define hypovitaminosis D as 25(OH)D concentrations <30 ng/mL. Age- and sex-specific SD scores (z scores) for BMI, height, and weight were calculated by using national reference standards. Sexual maturation was determined with a self-assessment pictorial questionnaire. Dietary intakes of calcium and vitamin D were assessed via three 24-h recall interviews. Fat mass and lean body mass were determined by DXA.
The median concentration of 25(OH)D was 28 ng/mL, and 55% of subjects had 25(OH)D concentrations <30 ng/mL. 25(OH)D concentrations were inversely correlated with PTH concentrations but were not significantly correlated with 1,25-dihydroxyvitamin D concentrations. In the multivariable model, older age (P < 0.001), black race [odds ratio (OR): 14.2; 95%CI: 8.53, 23.5}, wintertime study visit (OR: 3.55; 95% CI: 2.29, 5.50), and total daily vitamin D intake <200 IU (OR: 1.58, 95% CI: 1.02, 2.46) were associated with low vitamin D concentrations. Fat and lean mass were not independently associated with vitamin D status in this healthy-weight sample.
Low serum 25(OH)D concentrations are prevalent in otherwise healthy children and adolescents in the northeastern US and appear to be related to race, low vitamin D intake, and season.
F. Weng, J. Shults, M. Leonard, et al. Risk factors for low serum 25-hydroxyvitamin D concentrations in otherwise healthy children and adolescents. Am J Clin Nutr;86:150-158 (July, 2007). [Correspondence: BS Zemel, Nutrition and Growth Laboratory, Division of Gastroenterology, Hepatology and Nutrition, The Childrens Hospital of Philadelphia, 3535 Market Street, Room 1560, Philadelphia, PA 19104-4399. E-mail: email@example.com.]
Children and teens who are overweight or at risk of becoming overweight have become a major health care concern in the United States. Results from the 1999-2002 National Health and Nutrition Examination Survey indicated that about 16% (over 9 million) of children and adolescents ages 6 to 19 years are overweight. Moreover, this proportion has tripled since 1980. Kentucky youth are among the most overweight in the nation. According to the 2004 Youth Risk Behavior Survey, 17% of Kentucky middle school students were overweight, and another 20% were at risk for becoming overweight.
Overweight children are more likely to suffer from many chronic diseases, such as type 2 diabetes, high cholesterol, high blood pressure, early maturation, and orthopedic problems. In addition, they may have psychological problems and lower self-esteem. Overweight children tend to become obese adults, and being overweight is an important risk factor for development of chronic diseases later in life, including diabetes, stroke, arthritis, heart disease, and various types of cancer. Furthermore, the economic cost of health care for overweight children is increasing. For youth 6 to 17 years of age, annual hospital costs associated with being overweight increased more than threefold, from $35 million (1979 to 1981) to $127 million (1997 to 1999).
Specific dietary factors related to children being overweight include: (a) consumption of high-energy-dense foods, (b) high dietary fat content and increased fast-food consumption, (c) high consumption of sugar-sweetened beverages and high-sugar food, (d) low fruit and vegetable consumption, (e) large portion sizes, and (f) low breakfast consumption. Weight problems in children have been discussed in relation to environmental issues, such as food availability, family eating patterns, and socioeconomic status.
A number of previous studies investigating childhood weight factors have focused on elementary school children. However, elementary school children have less opportunity to make their own food decisions than middle school children who are evolving from set menus in primary school to cafeteria menu choices in middle school. Therefore, this study investigated the relationship between weight status and dietary practices of middle school students in central Kentucky because it is a prime time for developing food-conscious choices and patterns for adult life. Specifically this study examined the relationship between weight status and consumption of fruits, vegetables, milk, soft drinks, and breakfast.
The current study analyzed cross-sectional data from a survey of middle school students in a central Kentucky public school district conducted in fall 2004. The county school system was comprised of 12 middle schools. The survey instrument used questions from the middle school Youth Risk Behavior Survey designed by CDC to monitor the prevalence of priority health risk behaviors among youth. Seven schools administered the survey to all students (sixth to eighth graders) and an additional school administered it to their eighth-grade students for a total survey population of 4,955. In most instances, the survey was administered during a single class period (usually the second).
To meet the objectives of the study, in addition to the demographic variables, eight questions from the dietary behavior category were extracted regarding students self-reported dietary intake of fruits, vegetables, milk, breakfast, and soft drinks during the 7 days preceding the completion of the survey. The present study applied CDCs classification criteria: children with a BMI-for-age below the 5th percentile were classified as underweight; children who were = 85th percentile but < 95th percentile were classified as at risk of being overweight; and children who were = 95th percentile were classified as overweight.
Healthy weight was associated with consuming fruits, vegetables, breakfast, and milk. Underweight and healthy-weight students consumed more fruits than students who were at risk of being overweight and overweight. Healthy-weight students consumed more "other vegetables" than students who were at risk of being overweight and more "other vegetables" and carrots than overweight students. Underweight students consumed breakfast more often than all other students, and healthy-weight students consumed breakfast significantly more frequently than students at risk of being overweight and overweight. Finally, overweight students had a significantly lower consumption of milk than all other students.
The findings of this study suggest that the majority of middle school students in central Kentucky are not eating an adequate number of servings of fruits, vegetables, and milk each day. In addition, the results indicate that skipping breakfast was more common in students who were either at risk for being overweight or who were overweight than students who were at healthy weight. These results are comparable to earlier studies that found that overweight or obese adolescents were more likely to skip breakfast than their normal or underweight peers.
In this study of central Kentucky middle school students, healthy-weight students consumed more milk than students who were at risk of being overweight or who were overweight. This finding is consistent with previous studies that found a negative association between low dairy product intake and weight status.
In order to enhance fruit and vegetable consumption among middle school students, variety and creativity in the appearance, taste, and packaging of fruits and vegetables in school foodservice menus are suggested. Educating and encouraging adolescents to consume lower-fat milk is another area for improvement. This can be done by making available and promoting 1% or nonfat milk in school cafeterias, as well as providing information on the different fat percentages of milk and the health benefits of low-fat milk to both students and parents. Interventions to encourage and assist parents in promoting fruit, vegetable, milk, and breakfast consumption are needed. Innovative school foodservice programs, such as those that provide conveniently packaged "grab-n-go" breakfasts have been found to be successful in increasing school breakfast participation.
In view of the alarming number of overweight children and the fact that the diets of many adolescents in the United States fall short of the recommended dietary standards, efforts to promote healthful weight management and beneficial dietary practices among youth are sorely needed. Research should be aimed at studies that explore ways to increase the consumption of nutrient-dense foods in middle school students, along with successful strategies for increasing the availability of healthful food choices. Because schools have extensive contact with adolescents, creative school foodservice strategies are needed to encourage healthful eating habits.
M Roseman, W Ka Yeung, J Nickelsen. Examination of Weight Status and Dietary Behaviors of Middle School Students in Kentucky. JADA;107(7) (July 2007). [Correspondence: Mary G. Roseman, PhD, RD, Department of Nutrition and Food Science, University of Kentucky, 120 Erikson Hall, Lexington, KY 40546-0050.]
LONGITUDINAL ASSESSMENT OF MICRONUTRIENT INTAKE AMONG AFRICAN AMERICAN AND WHITE GIRLS: THE NATIONAL HEART; LUNG; AND BLOOD INSTITUTE GROWTH AND HEALTH STUDY
Prospective, epidemiologic research has shown that a healthful dietary pattern providing sufficient nutrients can reduce the risk of some cancers, CVD, and conditions such as osteoporosis. Eating patterns that influence nutrient intake are established early in life. Many of the previous studies examining micronutrient intake among children have been based on cross-sectional data documenting intake only for a single day. Youth in the United States are likely to report low intakes of calcium; folate, magnesium, zinc and vitamins A and D. Low micronutrient intakes may be linked to long-term health risks, especially among African American girls who are at particular risk for developing CVD risk factors such as hypertension. For example, the combination of nutrients (calcium, magnesium, potassium) in the Dietary Approaches to Stop Hypertension diet may be an important factor in blood pressure reduction, and folate may have beneficial effects on blood pressure, as well.
Capitalizing on the availability of 3-day food intake data collected as part of the National Heart, Lung, and Blood Institute Growth and Health Study (NGHS), the researchers of this study examined micronutrient intake in a large sample of African American and white girls from childhood through adolescence. In addition, they updated analyses by using the most current Dietary Reference Intakes (DRIs), which allow the comparison of intakes to the Estimated Average Requirements (EARs) in addition to the Recommended Dietary Allowances (RDAs).
The NGHS was designed to measure the development of obesity and CVD risk factors (including dietary, psychosocial, environmental, and other factors) in 2,379 African American and white females over a 10-year period. Participants, aged 9 or 10 years at study entry, identified themselves (using census categories for race/ethnicity) as "black" or "white" non-Hispanic, with racially concordant parents or guardians. Girls were recruited at three study sites: the University of California at Berkeley, Berkeley, CA; the University of Cincinnati/Cincinnati Childrens Hospital Medical Center, Cincinnati, OH; and the Westat, Inc/Group Health Association, Rockville, MD. Each girl was interviewed in 10 approximately annual study years (henceforth referred to as "Years"). Retention rates were highest in Year 2 through Year 4 (96%, 94%, and 91%, respectively), declined to a low of 82% at Year 7 and increased to 89% at Year 10.
Three-day food records that had been previously validated were collected during Years 1 through 5 and Years 7, 8, and 10; the mean±standard deviation age at last birthday for girls with complete food diaries in these years was 9.5±0.5, 10.5±0.6, 11.5±0.6, 12.5±0.6, 13.5±0.6, 15.5±0.6, 16.5±0.6, and 17.9±0.2 years, respectively. Girls were instructed to record all food and drink for 3 consecutive days (2 weekdays and 1 weekend day). Beginning at Year 5, girls were asked to record the type and amount of supplements consumed, if any; before Year 5, there were no specific instructions to document supplement intake.
DRIs are nutrient reference standards that can be used for assessing and planning diets for healthy people. They are established considering the role of nutrients in long-term health. DRIs encompass four reference values: EAR, RDA, Adequate Intake (AI), and Tolerable Upper Intake level. For a specified indicator of adequacy, the EAR represents the nutrient intake estimated to meet the requirement of half the healthy people in a particular life stage and sex group. The EAR is used to calculate the RDA. The RDA, the average daily intake level that is sufficient to meet the nutrient requirement of nearly all healthy individuals, is intended to be a guide for the daily intake of an individual. If sufficient data are not available to calculate an EAR and set an RDA, the AI is provided for the nutrient. The AI represents a recommended daily intake level based on an observed or experimentally determined approximation of nutrient intake for a group (or groups) of healthy people that is assumed to be adequate.
African American girls consumed less vitamin A and D, calcium, and magnesium compared to white girls. Regardless of race, a substantial percentage of girls had intakes below the EAR: vitamin E (81.2% to 99.0%), magnesium (24.0% to 94.5%), folate (46.0% to 87.3%). Intakes of vitamins A, D, and C; calcium; and magnesium decreased across years. As girls aged, there was an increasing proportion with intakes below the EAR for vitamins A, C, B-6, and B-12.
The researchers evaluated micronutrient intake relative to the DRIs in a large sample of African American and white girls (ages 9 to 18 years). Overall, white girls tended to consume greater amounts of micronutrients compared to African American girls, with the exception of vitamins E and C, and zinc. For all girls, intake of vitamins A, D, and C; calcium; and magnesium tended to decrease across the years; however, the rate of decrease for vitamin D, calcium, and magnesium was greater among African American girls. Moreover, there were racial differences in intake trends over time for vitamins E, B-6, and B-12; folate; and zinc; which typically increased for white girls but remained stable or decreased in African American girls. Improving the diet to meet the nutrient reference standards may be an effective approach for reducing CVD risk, especially among African American girls. Regardless of race, these findings are of concern regarding the intake levels of several micronutrients. A substantial proportion of girls had intakes of vitamin E and magnesium that were well below the EAR. These findings also agree with past research that has shown that a significant percentage of female adolescents report low intake of folate.
Using the EAR cut-point method, the researchers found that a substantial percentage of African American and white adolescent girls consumed less than the current reference values for vitamin E, magnesium, folate, and calcium. Trends noted in micronutrient consumption cannot be attributed to changes in EI, as all longitudinal models were adjusted for total energy. Rather, these results imply that as girls aged, the nutrient density of their diet decreased, and this tendency was more pronounced among African-American girls. Food and nutrition professionals should focus their counseling efforts on improving diets of young girls, particularly those who are African American.
S Affenito, D Thompson, D Franko, et al. Longitudinal Assessment of Micronutrient Intake among African-American and White Girls: The National Heart, Lung, and Blood Institute Growth and Health Study. JADA ;107(7) (July 2007). [Correspondence: Ruth H. Striegel-Moore, PhD, Professor and Chair, Department of Psychology, Wesleyan University, 207 High St, Middletown, CT 06459-0408.]
The continual increase in prevalence of childhood overweight among US adults and children transcends all age, sex, and ethnicity groups considered by the National Health and Nutrition Examination Survey. Concern about the implications of this trend in terms of associated health risks and medical costs motivates research to explain why prevalence of overweight continues to rise, to explain why some groups are disproportionably affected, and to determine ways to effectively moderate the trend. Risk for overweight relates to age, sex, ethnicity, social norms, socioeconomic class, family composition, parents knowledge, attitudes, and beliefs, and childrens knowledge, attitudes, and beliefs. For example, the prevalence of childhood overweight is higher among non-Hispanic blacks (23.6%) and Mexican Americans (23.4%) than among non-Hispanic whites (12.7%); among women and individuals of lower incomes than among men and people of higher incomes; and among children of less-educated mothers compared to those of more-educated mothers. Although increased obesity rates are related to race and educational and occupational status of parents, these effects may be mediated through income. A multifaceted approach to explaining childhood overweight is suggested; the home environment and socioeconomic status (SES) background are important considerations.
Although low-income populations and certain ethnic groups experience higher rates of overweight, diet quality differences do not appear to be the primary mediating factors. Efforts to explain increased rates of childhood overweight should also consider changes in physical activity patterns. Additional investigation is needed to determine physical and social factors that increase risk for overweight and to suggest means of moderating childhood overweight. The present study investigated the relationship between childhood overweight and: (a) family structure (marital status, occupational status) and demographic variables (income, race and education); (b) parental control over childrens food intake; and (c) parental belief of the cause of overweight.
Parents of second-grade (7- and 8-year-old) students, who presumably have had at least 2 years of contact with the public school system, were surveyed to assess their concern for childhood nutrition and overweight. Young children were chosen because understanding of childrens early food preferences and the factors that influence their food likes and dislikes is needed. Survey questions were derived from literature related to the causes and potential prevention strategies for childhood overweight. In addition, questions that have been used in previous research were included for the survey. Surveys were sent to all parents of second-grade students (n = 320); 205 (64%) surveys were returned.
Children were categorized as being "at risk for overweight or overweight" if the age- and sex-specific BMI percentile was = 85th percentile. Children < 85th percentile for age- and sex-specific BMI were categorized as not at risk for overweight.
Most survey respondents were mothers (89.9%). About half were non-Hispanic black (51.5%), 40.2% were non-Hispanic white, 0.6% were Hispanic, and 4.1% were Asian/Pacific Islanders. Most were married (60.9%), and most worked full-time (58.6%). About one third (33.7%) were categorized as having high income, 16% were categorized as having middle income, and 39.6% were categorized as having low income. More than half of children measured (58.6%) were normal weight; 41.4% were at risk for overweight or were overweight (with 22.5% = 85th percentile but < 95th percentile, and 18.9% = 95th percentile for age- and sex-specific BMI).
Analyses indicate a significant relationship between childs weight status and the following variables: income, marital status, race, and belief in the primary cause of childhood overweight. There was no relationship between risk for overweight and parent/guardian education level, occupational status, or parental control. Parental belief in the cause of overweight explains 5.7% of the variability in childrens weight status. Furthermore, when considered alone, children with parents who indicate dietary factors are the most important causes of overweight are 2.40 times as likely to be at risk for overweight or be overweight in comparison to children of parents who believe physical activity-related factors are most important. This variable is highly related to income, with parents of low income being more likely to have children who are at risk for overweight or overweight and to respond that dietary factors are most important causes of overweight. Therefore, when controlling for income, the perceived cause of being overweight (diet vs exercise) is no longer significant as a predictor of overweight.
Family income is a strong predictor of childrens weight status, and the effects of other demographic/family structure variables are mediated through income. For instance, no independent effect of family structure on weight status of children was found, but being the child of unmarried parents is more common among low-income families in this study. Further investigation is needed to understand the effect of family structure on weight status and how action can be taken within existing types of family structures to improve nutrition and physical activity of children.
Family income is a strong predictor of childrens weight status; other family characteristics are weak predictors of weight status. In addition, parents who believe physical activity is a less-important cause of childhood overweight than dietary factors are more likely to have overweight children. Efforts should be made to convince parents, particularly lower-income parents, of the importance of physical activity. To address the weight-related disparity between children of varying income levels, school boards, as well as local, state, and federal governments, should develop policies to promote a physical and social environment that supports safe, feasible, and affordable opportunities for good nutrition and physical activity. Appropriate policy areas may include funding for parks/public space, recreation programs for children and adults, support and promotion of farmers markets in low-income neighborhoods (including acceptance of food stamps and Special Supplemental Nutrition Program for Women, Infants, and Children vouchers for payment), and encouragement for small neighborhood stores to stock more-healthful options. Social influences of nutrition inequities merit further investigation.
V Gray, S Byrd, J Cossman, et al. Family Characteristics Have Limited Ability to Predict Weight Status of Young Children. JADA;107(7) (July 2007). [Correspondence: Virginia B. Gray, PhD, RD, 13151 Fountain Park Dr, #C-400, Playa Vista, CA 90094.]
The number of grandparents in the United States raising their grandchildren has increased over the past 2 decades. Nationally, there are 2.4 million co-resident grandparents who are the primary caregivers for their grandchildren; of all African American grandparents residing with their grandchildren, 51.7% are primary caregivers. Of all grandchildren living in grandparent households, 35.1% are African American, with no parents present. Grandparent caregivers are at increased risk for physical and mental health problems, including diabetes, hypertension, cardiovascular disease, insomnia, and depression. These grandparents may neglect their own health while focusing on the needs of their grandchildren. Grandparents may also deal with the added stress of their caregiver roles by overeating, drinking alcohol, and smoking. According to a study in Atlanta, GA, among 100 African American grandparents raising their grandchildren, 54% had high blood pressure, 80% were overweight, and 48% consumed high-fat foods. African Americans, as a group, are at increased risk for obesity, cardiovascular disease, cancer, and other lifestyle-related diseases. However, increased consumption of fruits, vegetables, grains, and low-fat dairy products may decrease obesity, blood pressure, and stroke in the African American population. This pilot study explored the impact of an educational program on the nutrition and physical activity knowledge of African American grandparents raising their grandchildren. Grandparents opinions about the program were solicited, along with ways to improve future interventions.
The nutrition and physical activity intervention was implemented with urban, African American grandparents raising their grandchildren who were participating in a community-based intervention, Project Healthy Grandparents. Serving primarily low-income, African-American grandparent-headed families in the Atlanta, GA, area, Project Healthy Grandparents strives to improve the health and well-being of families through home-based nursing and social work case-management services, parenting classes, grandparent support groups, and referrals for legal assistance. Annually, 12 support groups and 10 parenting classes are open to all current and previous Project Healthy Grandparents participants.
The program consisted of 10 min to 15 min} nutrition and physical activity lessons, based on the National Heart, Lung, and Blood Institutes "Ways to Enhance Childrens Activity and Nutrition" (We Can!). We Can! is a behaviorally oriented program for caregivers and their children ages 8 to 13 years. The program was targeted specifically to the grandparents and was modified to be culturally appropriate. Each of the 10 grandparent-caregiver lessons, developed by two of the researchers, included a key message, PowerPoint presentation, and activity. A pretest, posttest one-group design was used to test grandparents nutrition and physical activity knowledge. The principal investigator wrote one true-false item for the first and last lessons and two items for each of the other eight lessons, resulting in an 18-item test. Items were written at a third-grade level and were reviewed by two of the other investigators for appropriateness. They were read to participants because of the lower-level reading skills of some of the grandparents. The pretest and posttest were identical and administered at the first session and 3 weeks after the last session, respectively. Two weeks after the posttest, a trained facilitator conducted a 1-hour focus group with 18 grandparents who attended at least six sessions. The focus group elicited participants perceptions of factors influencing what they learned, their motivational levels, reported behavior changes, satisfaction with the program, and suggested improvements. The intervention was implemented from January through May of 2006, during the first 15 minutes of 10 grandparent support groups and parenting classes. A nutrition graduate student facilitated the sessions. The average attendance was 26, with a range of 24 to 27 participants.
Three major themes emerged from the focus group, including influences related to cost, presence of grandchildren in the home, and cultural considerations. Cost was a major theme identified as grandparents responded to questions about the most important things learned about diet and physical activity, changes made in diet or physical activity, and materials used most frequently. Participants indicated they liked learning inexpensive ways to exercise around the house and neighborhood and found it helpful to learn the benefits of walking. They reported using the 1-lb rice sock weights and handout on inexpensive community nutrition and fitness resources provided as part of the program. One of the participants reported buying more fresh vegetables, but noted their higher cost as a barrier to a healthful diet.
The influence of having grandchildren in the home was the second major theme that emerged as participants answered questions about their motivation and barriers to make diet and lifestyle changes. Participants noted that they were motivated to make changes, but they had to consider their grandchildrens tastes and food preferences. One grandparent stated that she tries to eat nutritiously, but her grandchild is 12 and she "doesnt want to make her [grandchild] eat like that." The grandparents concluded that their motivation to make lifestyle changes stemmed from concerns about their own health and being able to care for their grandchildren and desires to prevent future health problems in their grandchildren.
Cultural influences on diet and preferences for traditional foods emerged as the third major theme regarding making lifestyle changes as a result of the program. The importance of culture and ethnic influences was evident as participants identified major barriers to their motivation, what they found most and least helpful about the program, and the program resources they utilized most frequently. One participant stated that it was difficult to stay motivated because there is to be "no salt, no fried chicken, no this, and no that. They have taken everything away." Another participant liked learning how to use breadcrumbs to bake a healthier version of "fried" chicken. The most frequently used materials included the "Do the Hand Jive!" handout, which featured using ones hands to judge portion sizes, and the Heart Healthy Home Cooking--African American Style booklet.
Findings indicate that urban African American grandparents raising their grandchildren were knowledgeable about nutrition and physical activity and were receptive to learning more. Perceived barriers to more-healthful eating and physical activity were financial costs, familys food preferences, and cultural influences. Future interventions should utilize a family-based approach to address these barriers and target behavior changes in both grandparents and their grandchildren.
J Kicklighter, D Whitley, S Kelley, et al. Grandparents Raising Grandchildren: A Response to a Nutrition and Physical Activity Intervention. JADA; 107(7) (July 2007). [Correspondence: Jana R. Kicklighter, PhD, RD, Division of Nutrition, Georgia State University, PO Box 3995, Atlanta, GA 30302-3995]
Obesity and overweight are growing worldwide concerns for the World Health Organization. In Canada, the combined economic burden from obesity and lack of physical activity is close to 10 billion Canadian dollars, accounting for almost 5% of the total health care expenditure. There is the need to aggressively promote lifestyle intervention, especially exercise.
There is some indication that bright light therapy might enhance the effectiveness of physical activity for weight loss. There is evidence that exposure to bright light modified the processing of serotonergic stimuli in the circadian system and has anti-depressant and energizing effects in patients with seasonal affective disorder (SAD). In addition to its neurohumoral role in mood regulation, serotonin is one of the neurotransmitters involved in moderating food intake and has been connected to controlling body weight by regulating energy balance. Since bright light therapy is unique in that it may have the potential to maximize the effects of a moderate exercise plan, impact carbohydrate metabolism and reduce soreness, a recent study from Canada studied the effects of bright light therapy and exercise on weight loss and body composition in overweight and obese individuals.
Twenty-five overweight and obese subjects were assigned to six weeks of moderate exercise with or without bright light treatment. Bright light treatment (5000 lux) was provided using the lightweight, portable Litebook light therapy device. Subjects in the exercise only group were asked to exercise three times per week and all subjects were asked to consume their normal amounts of food during the 6-week period. On the exercise days for the subjects receiving light therapy, they used the lightbox for 30 minutes in addition to the 30 minutes of light exposure during exercise. Weight, heart rate, blood pressure, BMI, and body fat composition were taken at the initial study visit, at the end of the 6-week exercise program and at a 3-month follow-up visit.
Body weight decreased significantly with exercise in subjects in the light and non-light treatment groups, but the change was not significantly different between the groups. Similar results were found for BMI. With exercise, body fat decreased significantly only in the light treatment group. There was a significant effect of the interaction of group by time on body fat composition, but the group by time interaction failed to reach statistical significance for body weight and BMI. Mood scores improved significantly with exercise in the light group, but no significant changes were noted regarding sleep.
The results of this preliminary study show that addition of bright light treatment to a 6-week moderate exercise program can alter body composition by significantly reducing body fat. Study subjects were asked not to diet or binge throughout the study, but food diaries detailing food preference and intake were not recorded, so it is not known whether changes in amounts consumed or eating pattern among those treated with the bright light accounted for the change in body fat mass. Changes in energy expenditure may also have accounted for the findings in this study. The reduction in body fat mass is of particular importance, because visceral fat mass has been particularly linked to the development of the metabolic syndrome. This study is an important step toward finding ways to maximize the effects of exercise.
Andrea Dunai, Marta Novak, Sharon A. Chung, et al. Moderate Exercise and Bright Light Treatment in Overweight and Obese Individuals. Obesity Research;15(7): 1749-1757 (July 2007). [Correspondence: Colin M. Shapiro, Department of Psychiatry, Toronto Western Hospital, University Health Network, 399 Bathurst Street, 7 Main- 424, Toronto, Ontario, Canada M5T 2S8. E-mail: firstname.lastname@example.org.]
In 2005, the Obesity Society and the American Society for Nutiriotn published a joint review and position statement on obesity in older adults. In addition to outlining the health hazards related to obesity, the paper made recommendations for weight loss in obese older adults, who were defined as individuals with a BMI >30 kg/m2 and age >65 years. However, this paper did not make special reference to or recommendations for older adults with a BMI in the overweight range of 25 to 29.9.
Since the BMI cut-off points and weight loss guidelines outlined above were based primarily on evidence from studies of middle-age adults or in populations with a broad age range, there is a limited amount of evidence based specifically on older adults. Therefore, a recent Canadian study set out to determine whether older adults with a BMI in the overweight range are at increased morbidity and mortality risk.
The study sample included 4968 elderly (>65 years) men and women from the Cardiovascular Health Study (CHS). Weight and height were measured at baseline and based on BMI, the subjects were grouped into normal-weight (20 to 24.9), overweight (25 to 29.9) and obese (>30) categories. The subjects were followed for up to 9 years to determine if they developed 10 weight-related health outcomes (myocardial infarction and stroke, type 2 diabetes, arthritis of hips or knees, observed sleep apnea, urinary incontinence, cancer, physical disability, and osteoporosis) that are pertinent to older adults.
Compared with the normal-weight group, the risks of myocardial infarction, stroke, sleep apnea, urinary incontinence, cancer, and osteoporosis were not different in the overweight group. The risks for arthritis and physical disability were modestly increased in the overweight group, while the risk for type 2 diabetes was increased by 78% in the overweight group. After adjusting for all relevant covariates, all-cause mortality risk was 11% lower in the overweight group.
A BMI in the overweight range was associated with some modest disease risks but a slightly overall mortality rate. These findings suggest that a BMI cut-off point of 25 may be overly restrictive for the elderly.
Ian Janssen. Morbidity and Mortality Risk Associated with an Overweight BMI in Older Men and Women. Obesity Research ;15(7): 1827-1840 (July 2007). [Correspondence: Ian Janssen, School of Kinesiology and Health Studies, Queens University, Kingston, Ontario,Canada, K7L 3N6. E-mail: email@example.com.]
The increasing prevalence of childhood obesity is a significant public health concern. Fourteen percent of children aged 2 to 5 years and 19% of children aged 6 to 11 years are now obese. Children with overweight or obesity are more likely to stay overweight or obese into adulthood, which may increase their risk for hypertension, CVD, and diabetes. During the past decade, the prevalence of type 2 diabetes has increased among children and respiratory diseases are also more common in overweight children. In a large study of children and adolescents aged 5 to 17 years, 58% of overweight children were found to have at least one CVD risk factor. Efforts to reduce the burden of pediatric obesity are needed and require identifying modifiable risk factors, including diet, for prevention. Trends in beverage consumption during the past several decades suggest that the overall nutrition profile of children is changing. Total EI from beverages is increasing in children leading to the hypothesis that excess energy from calorically sweetened beverages may be related to the increased prevalence of overweight among children. This article presents a food-based approach to identify predominant beverage intake patterns among preschool (aged 2 to 5 years) and school-aged children (aged 6 to 11 years) in the 2001-2002 National Health and Nutrition Examination Survey (NHANES) sample. The researchers determined whether specific beverage patterns were associated with overall diet quality, measured by the US Department of Agricultures (USDAs) Healthy Eating Index (HEI), and whether beverage patterns in preschool and school-aged children were related to BMI.
NHANES 2001-2002 is a complex, multistage probability sample of the noninstitutionalized population of the United States. Certain population subgroups, including adolescents aged 12 to 19 years, African Americans, and Mexican Americans, were oversampled to allow for precise estimates from each group. Of the 13,156 persons eligible in the 2001-2002 sample, 80% (n = 10,477) participated in the physical exams at the mobile examination center and 74% (n=9,701) had completed reliable dietary interview data. For this study sample, the researchers selected children aged 2 to 11 years, with complete dietary data (n = 1,992). The final sample available for analysis consisted of 541 children aged 2 to 5 years and 793 children aged 6 to 11 years.
Dietary intake was assessed using a single 24-hour dietary recall at the mobile examination center interviews. Dietary intake was conducted for children aged < 6 years by a proxy interview of the parent/caregiver. Assisted interviews (proxy and child) were conducted in children aged 6 to 11 years. For each participant, individual foods and beverages were reported during a 24-hour period, as well as a summary of daily energy and nutrient intake.
Four and five beverage clusters were identified for preschool and school-aged children, respectively. In preschool children, mean HEI differed between the fruit juice cluster (79.0) versus the high-fat milk cluster (70.9); however, both fruit juice and high-fat milk clusters had the highest micronutrient intakes. Mean HEI differed significantly across beverage patterns for school-aged children (from 63.2 to 69.9), with the high-fat milk cluster having the best diet quality, reflected by HEI and micronutrient intakes. Adjusted mean BMI differed significantly across beverage clusters only in school-aged children (from 17.8 to 19.9).
In this study, the researchers derived four and five nonoverlapping beverage patterns among children aged 2 to 5 and 6 to 11 years, respectively, in the 2001-2002 NHANES sample using cluster analysis. The objectives were to understand the association of different beverage patterns with overall diet quality, measured by HEI, among children and to identify if BMI in children was associated with different beverage patterns. Overall, these results showed that diet quality differed significantly across beverage patterns for both age groups of children. However, beverage patterns were only related to BMI for children aged 6 to 11 years.
No formal guidelines have been established for beverage consumption in children or adults. However, a recent guidance system has been proposed for beverage consumption in persons >6 years of age, which ranks beverages based on energy and nutrient content and related health benefits and risks. The Beverage Guidance Panel recommends water as the most preferable beverage, followed by unsweetened coffee and tea, low-fat milk, noncalorically sweetened beverages, fruit juices, and alcohol (with some nutrients), and calorically sweetened beverages (without nutrients). In the current sample of children aged 2 to 11 years, the beverage patterns identified were not consistent with what has been proposed by the Beverage Guidance Panel. Although the mix/light drinker pattern in both age groups had combinations of all beverage groups, a large proportion of this pattern was made up of calorically sweetened beverages.
The researchers observed that diet quality differed across distinct beverage patterns among children aged 2 to 5 and 6 to 11 years, but BMI was only significantly associated with beverage patterns of children aged 6 to 11 years. These data suggest that beverages are associated with diet quality in children. Moreover, mean HEI scores among children in all beverage clusters were below 81 (a score of 81 or greater representing a "good" diet), indicating that diets of children aged 2 to 11 years need improvement. Regardless of beverage pattern, all children could benefit by decreasing their intake of soda and other calorically sweetened beverages that may displace important micronutrient-dense foods needed for growth and development. Further research using prospective studies is needed to better assess the influence of beverage consumption on diet quality and its influence on overweight in children.
T LaRowe, S Moeller, A Adams. Beverage Patterns, Diet Quality, and Body Mass Index of US Preschool and School-Aged Children. JADA;107(7) (July 2007). [Correspondence: Tara L. LaRowe, PhD, Postdoctoral Fellow, Department of Family Medicine, University of Wisconsin-Madison, 777 S Mills St, Madison, WI 53715.]
Annual expenditures on weight-loss products exceed $30 billion in the United States. Despite these costs, the prevalence of overweight and obesity continues to escalate. Approximately 47.4% of Americans were overweight and 15.1% obese during 1976 to 1980, as compared to 65.1% and 30.4% during 1999 to 2002. In particular, women, minorities, and people of low socioeconomic status are affected disproportionately by obesity. The prevalence rates among men do not differ by ethnicity; however, in women, more African Americans and Hispanics are obese (49.0% and 38.4%) than whites (30.7%). Environmental contributors to weight loss include diet, physical activity, and psychosocial factors. Restriction of caloric intake and expenditure of calories via physical activity are the primary mechanisms for the promotion of energy deficits. Dietary components associated with weight loss include higher intakes of protein, complex carbohydrates, dietary fiber, and dairy products; and lower intakes of fat.
Physical activity represents the expenditure side of caloric balance. The Institute of Medicine recommends 1 hour per day of physical activity, based on evidence that this amount may be needed to maintain a healthy weight. Psychosocial influences on weight loss may be especially pertinent for women. Higher rates of depression and deteriorating body image have been associated with increased weight after pregnancy, resulting in lowered self-esteem. Strategies to enhance weight loss focus on improved self-efficacy and reduced stress levels. Models for weight management for low-income mothers are limited. This study aims to identify predictors of weight loss in a sample of low-income mothers of young children.
Mothers (n = 114) of 1- to 4-year-old children participated in an 8-week dietary and physical activity program. This intervention assessed pre- and postmeasurements of body weight, diet, physical activity, and psychosocial factors (body image, decisional balance, depression, nutrition attitudes, nutrition knowledge, exercise self-efficacy, social support, and stress). Demographics and health and dieting history were evaluated at baseline.
Mothers were recruited from community centers, public health clinics, and Special Supplemental Nutrition Program for Women, Infants, and Children clinics in central Texas. Subject qualifications included: age 18 to 45 years; BMI =25; African American, white, or Hispanic ethnicity; ability to speak and read English; and income < 200% federal poverty index. Pregnant, lactating (breastfeeding =5 minutes/day), and seriously ill subjects were excluded.
Childbirth and demographic data were obtained with a 40-item questionnaire. Subjects reported information regarding gestational weight gain, number of children, ethnicity, income, education, relationship status, birth control use, employment status, and Medicaid insurance eligibility. Participants listed current and past medical conditions (colitis, depression, diabetes, hypertension, thyroid disorders) on a health history form. In addition, mothers stated the number of previous attempts at weight loss and current dieting status.
A registered dietitian collected 3 days of dietary data from participants at baseline and postintervention. All subjects reported 1 day with the 24-hour recall method initially and then completed 2 days of food records (1 weekend day), to yield a total of 3 days of dietary intake data at each measurement interval. Daily pedometer steps were used to appraise physical activity levels. At pre- and postintervention, mothers reported steps and duration from pedometers worn for 3 days (2 weekdays and 1 weekend day). Subjects were instructed to wear the pedometer for all waking hours except during swimming or bathing. Pedometer forms were checked by staff for extreme step and time values. In addition, the 3 days of steps were averaged to yield mean pedometer steps for each participant at baseline and week 8.
At pre- and postintervention, mothers completed questionnaires assessing body image, pros and cons of weight loss, depression, nutrition attitudes, knowledge, self-efficacy, social support, and stress. Body image was measured with the 34-item Multidimensional Body Relations Questionnaire. This tool assessed five domains representing satisfaction with appearance (appearance evaluation), effort expended on appearance (appearance orientation), satisfaction with distinct body parts (body areas satisfaction), fixation with dieting, weight vigilance, and eating restraint (overweight preoccupation), and perception of current weight status (weight classification). The pros and cons of weight loss were appraised with the 20-item Decisional Balance Inventory. Pros represented the benefits of weight loss, such as wearing more attractive clothing and feeling more energetic, while the cons corresponded to negative attributes, such as paying more for meals and eating less-appetizing foods. Depression was evaluated with the 20-item Center for Epidemiological Depression Scale.
Higher weight loss was more prevalent among women who lived with a spouse/partner. This finding may reflect the influence of social support and increased resources on behavior change. The three variables that were significantly related to weight loss, but did not retain significance in the model, were decisional balance, nutrition knowledge, and appearance evaluation. For decisional balance, scores on the pro subscale were associated with weight reduction, yet cons only marginally influenced the outcome measure. This meant that mothers who felt the benefits of weight loss outweighed the barriers were more likely to be successful. Therefore, positive messages may have had a greater impact on a low-income population than negative ones for behavioral change. Nutrition knowledge was higher in those who were successful in losing weight. Physical activity, as measured by pedometers, was not related to weight loss, presumably because 82% of subjects increased their activity.
Predictors of weight loss included enhancements in nutrition attitudes and social support. Greater success was observed in those who articulated the benefits of weight loss, had higher nutrition knowledge, and had lower satisfaction with appearance at baseline.
Further research is needed to develop long-term models of weight management for low-income mothers. Specifically, there is a need for culturally sensitive resources to guide the weight-loss efforts of ethnically diverse women in the United States.
K Clarke, J Freeland-Graves, D Klohe-Lehman. Predictors of Weight Loss in Low-Income Mothers of Young Children. JADA;107(7) (July 2007). [Correspondence: Jeanne Freeland-Graves, PhD, RD, Division of Nutritional Sciences, 1 University Station, A2700, The University of Texas at Austin, Austin, TX 78712.]
The prevalence of obesity in the United States and worldwide has risen dramatically over the past 2 decades. Identification of the causes of this complex multifactorial disease has been as difficult as the disease is pervasive. Among the many contributing factors are increasing portion sizes and increased consumption of fast food. Larger portion sizes, coupled with the fact that most Americans underestimate portion sizes and tend to eat more when portions are larger, results in consumption of excess calories, contributing to the obesity epidemic. Just as portion sizes have increased over the past 15 to 20 years, so has the frequency of eating outside the home. The number of fast-food meals eaten per week is positively associated with total EI, percentage of energy from fat, and BMI in women. Reducing or altering fast-food intake could result in improvement in weight status. Changing behaviors to promote weight management remains a challenging and elusive process. According to the Prochaskas Transtheoretical Model of Behavior Change, progressive behavior changes are facilitated by intervention methods known as change processes. Emotional arousal (also called dramatic release or catharsis) and consciousness-raising (increasing level of awareness and information available to individuals) are change processes that can assist individuals in making changes to improve their health.
Commercial films and television programs are forms of media that can increase knowledge of health issues, while simultaneously appealing to the emotions of viewers. An emotionally arousing and consciousness-raising film that may contribute to behavior change, Super Size Me, illustrates the detrimental effects of a diet consisting entirely of fast food. Following its release, Super Size Me received extensive press coverage because of its unique and somewhat shocking subject matter. Media sources provided commentary on the film, some even citing its potential to alter eating behavior. USA Today reported that the film could "work effectively to change minds and behavior." This film, as a form of emotional arousal and consciousness-raising may be a vehicle for initiating changes, such as reducing fast-food intake, that help combat the problem of obesity. Thus, the purposes of this study were to examine the effects of the film Super Size Me on college students fast-food knowledge, attitudes, self-efficacy, healthy weight locus of control, and stage of change. A second purpose was to evaluate the films effectiveness as a form of emotional arousal and consciousness-raising for maintaining a healthy weight and following a healthful diet.
The sample was comprised of young adults (18 to 26 years) enrolled in an introductory psychology course at Rutgers University. In return for participation, participants received research points required by this course. College students were studied because they consume fast food frequently. A pretest-posttest follow-up control group design with random assignment was used. Both the experimental and control groups completed the pretest, posttest, and follow-up test. The pretest included all eight of the questionnaires described here. All questionnaires, except the demographic questionnaire, were completed again at the posttest and follow-up test. Participants completed the pretest online. An average of 10 days later, they participated in the intervention (that is, viewed a movie). The experimental group saw Super Size Me and the control group was shown either the movie Finding Neverland or First Daughter, neither of which was related to nutrition. Participants were blind to the movie that would be shown until they arrived at the showing. To assess short-term effects, immediately following the intervention, both groups completed the posttest in a pencil-and-paper format. An average of 9 days later, both groups participated in the online follow-up test administered to examine persisting effects of the film.
The study included eight instruments. The first instrument collected demographic information (that is, age, sex, race/ethnicity, college major, number of college level nutrition courses completed, height, weight, personal weight satisfaction, personal and family history of obesity-related health conditions, recent movies seen, and books read). The second instrument assessed knowledge related to nutrition, fast food, and obesity-related health conditions and was based on factual information presented in the movie Super Size Me. Fast-food knowledge score was computed by awarding one-point for each correct answer and summing the total. The remaining instruments assessed psychosocial measures including attitudes, self-efficacy, locus of control, stage of change, emotional arousal, and consciousness-raising. The third instrument was a 16-item Likert-type attitude questionnaire with three constructs (scales): Perceived Personal Susceptibility to Obesity and Related Health Conditions, Feelings About the (Un)Healthfulness of Fast Food, and Personal Concern about Maintaining a Healthy Weight. The fifth instrument assessed nutritional locus of control, which is the degree to which an individual believes that following a nutritious diet and maintaining a healthy weight is controlled internally, by powerful others, and/or by chance. The sixth instrument was a single item designed to assess participants stage of change (that is, precontemplation, contemplation, preparation, action, and maintenance) for reducing fast-food intake. The last two instruments were Likert-type scales using the same response choices and scoring method as the attitude scales.
A total of 194 individuals participated in the study; 135 remained after eliminating 12 that did not complete all study parts, one who was older than age 26 years, and 46 that had previously seen Super Size Me and/or had read Fast Food Nation. The final sample size was 135 participants, with the experimental group being larger (n = 80 versus 55 for control) because of several factors, including a priori decisions regarding participation and group assignment of those who had seen Super Size Me and/or read Fast Food Nation, group assignment based on availability at the times films were to be shown, and attrition. Mean age was 19.3±0.06 standard error years (range 18 to 23 years). The majority were female (n = 73; 54%) and white (n = 71; 53%). Participants were from a wide variety of majors, with business being the most common (n = 23; 17%). The majority (n = 132; 98%) had not completed any college-level nutrition courses. The mean BMI, 22.7±0.38, indicated the average participant was a healthy weight. Overall, participants were fairly satisfied with their body weight; only about 11% in both study groups reported they weighed a lot less or a lot more than they would like. Obesity-related health conditions were uncommon among participants. In contrast, these conditions were common among their immediate family members with the dominant problems being hypertension (n = 64; 47%), high blood cholesterol (n = 56; 41%), obesity-related cancers (n = 34; 25%), type 2 diabetes (n = 27; 20%), heart disease (n = 25; 19%), and respiratory problems (n = 21; 16%). Participants (n = 25; 19%) reported that one or more individuals in their immediate families were obese.
Knowledge test data revealed that at the pretest, participants in both study groups correctly answered about two thirds of the questions. ANCOVA, with mean pretest knowledge score as the covariate, indicated that the experimental groups mean posttest knowledge score was significantly greater than the control group, indicating that Super Size Me increased their knowledge. Furthermore, ANCOVA revealed that the experimental groups mean follow-up knowledge score was significantly higher than that of the control group.
Both groups had positive attitudes at baseline. ANCOVA revealed that the groups did not differ at posttest or follow-up on the Perceived Personal Susceptibility to Obesity scale. However, the experimental groups mean score for Feelings About the (Un)Healthfulness of Fast Food was significantly higher at the posttest, indicating that they believed fast food was less healthful immediately after seeing Super Size Me. Although the groups differed substantially on this scale at the follow-up test, this difference appears to be due to a decrease in the control groups mean score rather than a change in the experimental groups mean score. The experimental groups mean score on the Personal Concern about Maintaining a Healthy Weight scale was significantly higher than the control group at the posttest, indicating that they were more concerned about maintaining a healthful weight after seeing Super Size Me. This significant difference was not retained at follow-up test.
Both groups began the study with a high level of self-efficacy; that is, they were confident in their ability to control fast-food intake (3.82±0.62). At the posttest, results of ANCOVA revealed that after seeing Super Size Me, the experimental group scored significantly higher than the control group, a difference that was not evident at the follow-up test. The experimental group scored significantly higher than the control group on the internal health locus of control scale at the posttest. No significant difference was found between these groups on the internal health locus of control measure at the follow-up test. The groups did not differ significantly on the external: powerful others locus of control scale at the posttest or follow-up test. In contrast, the experimental group scored significantly lower on the external: chance locus of control scale than the control group at both the posttest and follow-up tests.
Both study groups began the study in the preparation stage for reducing fast-food intake. The experimental group advanced to a significantly higher stage at the posttest than the control group. This significant difference was maintained at the follow-up test.
Mean emotional arousal posttest scores differed significantly; in specific, the experimental groups posttest score was significantly higher than the control groups mean score indicating the experimental group was more emotionally aroused after seeing Super Size Me than the control group. For the follow-up test, however, no significant difference was found.
Results indicate that Super Size Me led to an increase in knowledge of nutrition, fast food, and obesity-related health conditions that persisted at least an average of 9 days after viewing this film. These results support recent research investigating the impact of broadcast media on knowledge. Overall, Super Size Me had short-term effects on attitudes about the (un)healthfulness of fast food and personal concern about maintaining a healthful weight. These findings are similar to those reported by others that viewing a health-related drama program had a substantial impact on health-related attitudes. Exposure to the movie Super Size Me substantially increased the experimental groups self-efficacy for minimizing intake of fast food in the short term. The evidence that merely watching a film can produce changes comparable to educational exercises or counseling sessions lends support to the concept of film as a powerful motivational tool, at least in the short term. Considering the difficulty in making and maintaining dietary changes and success of mass-media campaigns, incorporating Super Size Me into a comprehensive, structured nutrition intervention program targeting obesity would perhaps render it even more successful in facilitating behavior change. Future research should investigate the effect of this film on other audiences. In addition, the usefulness of Super Size Me as a part of a comprehensive nutrition education program that includes follow-up measures administered after an extended period is recommended. Food and nutrition professionals practicing in the field of weight management could benefit patients by incorporating this film into behavioral counseling sessions or utilizing it as a consciousness-raising and emotional arousal adjunct to counseling. Incorporation of Super Size Me into weight-management interventions may substantially affect individual client outcomes, and may ultimately lessen the impact of the obesity epidemic.
E Cottone, C Byrd-Bredbenner. Knowledge and Psychosocial Effects of the Film Super Size Me on Young Adults. JADA; 107(7) (July 2007). [Correspondence: Carol Byrd-Bredbenner, PhD, RD, FADA, Rutgers University, 26 Nichol Ave, 220 Davison Hall, New Brunswick, NJ 08901.]
Moderate alcohol intake has been associated with lower risk of type 2 diabetes, whereas high intake seems to increase the risk. Beneficial effects of moderate alcohol intake on insulin sensitivity have been reported but have not been consistent. Alcohol may also have acute effects on insulin secretion, which also questions the validity of previous studies on the influence of alcohol on insulin sensitivity. Additionally, alcohol might affect body fat distribution, which in turn could modulate insulin sensitivity. Since insulin resistance, insulin secretion, and abdominal obesity are major predictors of diabetes, a group of Swedish researchers studied the association between alcohol intake and these three major factors predicting type 2 diabetes.
In a population-based cohort of 807 men, insulin sensitivity was measured with the euglycemic clamp. Insulin sensitivity was calculated as glucose infusion rate during the last 60 minutes of the 2-hour clamp. Insulin secretion was assessed as the early insulin response (EIR) during an oral glucose tolerance test. Alcohol intake was self-reported via a questionnaire and was assessed from a validated 7-day food record. Height and weight were measured and BMI was calculated, along with waist circumference (WC) and WHR. Other topics assessed via interview questions included smoking, education level, physical activity, hypertension, diabetes, triglycerides, and cholesterol.
Self-estimated alcohol intake was not related to insulin sensitivity, early insulin response or BMI, but was positively related to WC and WHR. The relationship with WC and WHR was most pronounced in men in the lowest tertile of BMI. In analyses examining the relation of number of drinks per week to WC, each additional drink per week was associated with an increased WC of 0.12 cm in multivariable regression models. In analyses of the associations between different types of alcohol (beer, wine, and liquor) and insulin sensitivity and obesity measures, a higher liquor intake was significantly associated with increased BMI, WC, and WHR. Neither beer nor wine intake was significantly associated with insulin sensitivity, EIR, BMI, WC, or WHR.
In this large, community-based cohort of elderly men, there were no associations between alcohol intake and insulin sensitivity or insulin secretion. However, there was a strong association between high alcohol intake and increased abdominal fat distribution. Given that abdominal obesity is an independent risk factor of diabetes and might precede insulin resistance, these findings are in line with data indicating increased diabetes risk in subjects with excessive alcohol intake. Considering the increasing prevalence of abdominal obesity, the data support current dietary recommendations for type 2 diabetes, that is, to limit excess alcohol intake. The strengths of the study include the large sample size and use of the euglycemic clam, which is the gold standard of measurements. Some of the limitations include the cross-sectional design does not allow assumptions of cause and effect and the generalization of the findings to women, other ethnicities, or other age groups is unknown. Therefore, the results need further confirmation in other studies to better clarify the link between alcohol intake and adiposity, including body fat distribution.
Ulf Riserus and Erik Ingelsson. Alcohol Intake, Insulin Resistance, and Abdominal Obesity in Elderly Men. Obesity Research ;15(7): 1766-1773 (July 2007). [Correspondence: Ulf Riserus, Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala Science Park, 751 85 Uppsala, Sweden. E-mail: firstname.lastname@example.org.]
Type 2 diabetes mellitus (DM) affects more than 18 million Americans and is associated with major health care problems and costs. Although genetic factors play an important role in the etiology of DM, there is data that indicate that modifiable lifestyle risk factors may also influence the risk of DM. Alcohol consumption has been shown to improve insulin sensitivity but the results have been inconsistent. It is believed that no previous study has examined the effects of alcohol consumption on the risk of DM in a cohort of subjects 65 years of age and older. Therefore, a recent article in Obesity Research examined whether self-reported moderate alcohol consumption was linked to a lower incidence of DM among elderly men and women who were free of DM at baseline.
Data was used from 4655 men and women 65 years of age and older from CHS who were free of DM at baseline. Baseline examination included standardized questionnaires, physical examination, resting electrocardiography, anthropometric measurements, and laboratory examination. Follow-up contact occurred every 6 months, alternating between telephone calls and clinic visits. Alcohol consumption was reported from a questionnaire and DM was defined using fasting glucose and/or use of hypoglycemic medications.
Of the 4655 subjects, 41% were men, 13% were blacks and 86% non-blacks. During an average follow-up of 6.3 years, 234 incident cases of DM occurred. Compared with never drinkers, hazard ratios for DM were 0.7, 0.5, 0.6, and 0.8 for former drinkers and current drinkers of <1m 1 to 6, and 7+ drinks per week, respectively for men. Corresponding values for women were 1.2, 0.7, 0.6, and 0.4, respectively. A reduced risk of DM was observed in subjects who preferred beer, wine, spirits, or more than one type of alcoholic beverage. Alcohol consumption was association with lower fasting insulin and a measure of insulin sensitivity.
The results showed that light to moderate alcohol consumption (up to 6 drinks/week) was associated with a 40% lower risk of DM in this elderly cohort of men and women. However, the data did not show a clear dose-response relation between light to moderate alcohol consumption with DM. One limitation of this study is that alcohol information was self-reported and it is possible that under-reporting could lead to erroneous classification of heavy drinkers as moderate drinkers. Nevertheless, the large sample size, the prospective design, the multicenter and multiethnic natures of the study and the large number of covariates examined are strengths of this study.
Luc Djousse, Mary L. Biggs, Kenneth J. Mukamal, et al. Alcohol Consumption and Type 2 Diabetes Among Older Adults: The Cardiovascular Health Study. Obesity Research;15(7): 1758-1765 (July 2007). [Correspondence: Luc Djousse, Division of Aging, Brigham and Womens Hospital and Harvard Medical School, 1620 Tremont St, 3rd Floor, Boston, A 02120. E-mail: email@example.com.]
Obesity in the United States has risen to epidemic proportions and is a particular problem among black women, one half of whom are obese. As a result of the rise in obesity, there is an emerging epidemic of type 2 diabetes, with 20 million Americans being affected by this condition. Incidence rates of type 2 diabetes are twice as high in black women as in white women. Studies of whites indicate that central, or abdominal, obesity is an independent risk factor for diabetes, but there have been no data on black women. Therefore, a recent study out of Boston examined the association of BMI, abdominal obesity, and weight gain with risk of type 2 diabetes.
The Black Womens Health Study (BWHS) is a prospective follow-up study of 59,064 African-American women. During eight years of follow-up of 49,766 women from the BWHS, 2472 incident cases of diabetes occurred. Information on current weight, height, waist circumference, hip circumference and weight at age 18 was collected at baseline. Weight was updated on each follow-up questionnaire and BMI was calculated for each follow-up cycle. Physical activity, family history of diabetes, cigarette smoking, years of education was also assessed at baseline and at each follow-up.
Sixty-one percent of the women had a BMI > 25 kg/m2 (WHO definition of overweight) and 29% had a BMI of 30 or greater, which is considered obese. The prevalence of obesity was higher among those who reported a family history of diabetes than among those who did not. Obesity was also related to cigarette smoking, lower levels of education, and low levels of physical activity. The prevalence of women in the highest quintile of waist circumference was higher among those with a family history of diabetes. There was a strong linear trend of increasing risk of diabetes with increasing BMI. Compared with a BMI of <23, the incidence rate ratio (IRR) for a BMI of >45 was 23. The IRR for the highest quintile of WHR relative to the lowest was 2.3 after controlling for BMI. Additionally, at every level of BMI, an increased risk was observed for high WHR relative to low.
The results indicate that BMI is a strong predictor of type 2 diabetes in black women. In general, the most overweight women (BMI > 45) had 23 times the risk of developing diabetes as women who were not overweight. In addition, waist circumference and WHR were independently associated with risk of diabetes, indicating that abdominal obesity is also relevant to the development of diabetes. Therefore, this study reinforces the need for efforts to reduce the prevalence of obesity in African American women.
Supriya Krishnan, Lynn Rosenberg, Luc Djousse, et al. Overall and Central Obesity and Risk of Type 2 Diabetes in U.S. Black Women. Obesity Research;15(7): 1860-1866 (July 2007). [Correspondence: Supriya Krishnan, Slone Epidemiology Center, 1010 Commonwealth Avenue, Fourth Floor, Boston, MA 02215. E-mail: firstname.lastname@example.org.]
Obesity results from an energy imbalance, whereby energy intake is greater than energy expenditure. In youth in the United States, low levels of physical activity and high levels of inactivity documented in nationally representative surveys are believed to play a causal role in the development of obesity. In children, where weight and fatness changes are part of normal growth, it is both methodologically and analytically challenging to demonstrate the impact of physical activity on these changes.
The Massachusetts Institute of Technology (MIT) Growth and Development Study was initiated in 1990 with the enrollment of 196 non-obese pre-menarcheal girls. Since the impact of activity and inactivity on relative weight and fatness change are best evaluated longitudinally, a current study examined the longitudinal relationship of physical activity, inactivity, and screen time with relative weight status and percentage body fat (%BF) and explored how it differed by parental overweight status.
One hundred and seventy-three non-obese pre-menarcheal girls, 8 to 12 years old, were followed until four years post-menarche. Percent body fat, BMI z-score, and time spend sleeping, sitting, standing, walking and in vigorous activity were assessed annually via measurements and a questionnaire. Subjects also completed a food frequency questionnaire and a physical activity index was developed to reflect time and intensity of activity. Inactivity was defined as the sum of time spent sleeping, sitting, and standing. Screen time was defined as time spent viewing television, videotapes or playing video games. Parental overweight was defined as at least one parent with BMI > 25.
At baseline, 63% of girls were Tanner Stage 1, and 37% were Tanner Stage 2 or 3. The mean age at menarche was 12.88 years. Subjects spent an average of 4.2 hours/day being active at baseline and 3.7 hours/day being active at exit. Inactivity time increased from 19.8 to 20.3 hours/day between baseline and exit, although screen time declined by one-half over that period. Activity, inactivity, and screen time were unrelated to BMI z-score longitudinally, with and without accounting for parental overweight. After controlling for parental overweight, activity was inversely related, and inactivity was directly related to increased %BF longitudinally. Screen time was unrelated to %BF change. With stratification for parental overweight, effects of activity and inactivity on %BF were observed only among girls with at least one overweight parent.
In this cohort of initially non-overweight girls, activity and inactivity were related to accrual of BF over adolescence, particularly among children with at least one overweight parent. These results suggest that girls with a family history of overweight represent a target population of high priority for interventions around physical activity and inactivity. Since there was not a direct relationship between %BF and screen time, it suggests that for girls in this age group, time spent viewing television and videotapes and playing video games may not be a good proxy for inactivity.
Aviva Must, Linda G. Bandini, David J. Tybor, et al. Activity, Inactivity and Screen Time in Relation to Weight and Fatness Over Adolescence in Girls. Obesity Research;15(7): 1774-1781 (July 2007). [Correspondence: Aviva Must, Department of Public Health and Family Medicine, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts 02111. E-mail: email@example.com.]
The prevalence of overweight in children and adolescents in the United States has increased, calling for evaluations of the causes and consequences of obesity and subsequent preventative interventions. One potential contributing factor to the rise in obesity is a decline in physical activity (PA). Research studies have documented low PA levels of adolescents, particularly in girls. To address the low activity levels of adolescent girls, a multi-site intervention [Trial of Activity in Adolescent Girls (TAAG)] was developed.
Patterns of PA in adolescents, and, in particular, these patterns in relation to overweight, have not been explored sufficiently with activity measured using accelerometers, rather than self-report methods. Accelerometers can quantify activity for a single day, over several days, or over a combination of days, more accurately than self-reports. The use of accelerometers or activity monitors has also become a promising method to differentiate among the various intensities of PA. Therefore, a recent article described the patterns of PA of sixth grade girls enrolled in TAAG using the baseline accelerometer data before randomization and intervention. Treuth et al also explored activity differences between normal-weight girls versus at-risk of overweight and overweight girls.
Healthy sixth grade girls (n = 1603), 11 to 12 years old, were randomly recruited from 36 schools participating in TAAG. Age, ethnicity, and socioeconomic status were obtained from a self-report questionnaire. Height and weight were measured. The girls were instructed to wear the accelerometers for seven complete days except when sleeping, bathing, or swimming.
Adoelscent girls spend most of their time in sedentary (52% to 57% of the day) and light activity (40% to 45% of the day) on weekdays and weekends. In all girls, total PA comprised 44.5% of the day (41.7% light, 2.2% moderate, and 0.7% vigorous) with sedentary activity comprising 55.4%. Moderate to vigorous PA (MVPA) was higher on weekdays than weekends in all girls, but MVPA was lower in at risk of overweight and overweight girls on both weekdays and weekends compared with normal weight girls.
The results of this study suggest that middle school girls, regardless of weight status, spend the majority of their days in sedentary and light PA. In addition, differences in MVPA between weekdays and weekends were observed in the girls. This has implications in terms of the age to target individuals for various intervention strategies that might focus on altering weekend behavior. The differences noted may be due to greater television viewing time on weekends. A general intervention approach for all girls could be to increase total daily activity in a healthful direction by reducing sedentary time and this would have modest effects on improving energy balance.
Margarita S. Treuth, Diane J. CAtellier, Kathryn H. Schmitz, et al. Weekend and Weekday Patterns of Physical Activity in Overweight and Normal-weight Adolescent Girls. Obesity Research;15(7): 1782-1788 (July 2007). [Correspondence: Margarita S. Treuth, Center for Human Nutrition, The Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205. E-mail: firstname.lastname@example.org.]
More than 33% of youth are overweight or oat risk for overweight status. In addition to the numerous negative health consequences associated with overweight status, such as type 2 diabetes and early CVD, overweight status in childhood and adolescence has significant psychological consequences. Overweight youth are more likely to experience peer victimization, behavior problems, low self esteem, and body dissatisfaction than their non-overweight peers. Given the serious physical and mental health consequences associated with pediatric obesity, further data are needed to help elucidate factors that impact psycho-social functioning.
Measurement of health-related quality of life (QOL) is one method for assessing psychosocial functioning. Research has shown that overweight children report lower QOL than their non-overweight peers. An article in Obesity Research extended the literature by examining the association between peer victimization, child depressive symptoms, parent distress, and health-related QOL in overweight youth.
Ninety-six overweight and at risk for overweight children and their parents were recruited from a Pediatric Endocrinology Obesity Clinic. The parents completed a demographic questionnaire, the Pediatric Qualtiy of Life Inventory-parent-proxy version, and the Brief Symptom Inventory. Children completed the Childrens Depression Inventory-Short Form, the Schwartz Peer Victimization Scale and the Pediatric Quality of Life Inventory.
The subjects had a variety of co-severe obesity-related health conditions: type 2 diabetes (12.5%), metabolic syndrome (4.2%), sleep apnea (5.2%), and hypertension (10.4%). Seventy-five percent of the sample reported experiencing some peer victimization, with 15% experiencing peer victimization on a daily basis. Increased parent distress, child depressive symptoms, and peer victimization were associated with lower QOL by both parent-proxy and self-report. Child depressive symptoms mediated the relationship between psychosocial variables (parent distress and peer victimization) for self-reported QOL but not for parent-proxy-reported QOL.
This study documented the important impact of peer victimization and parental distress on the QOL of overweight children. Expanding our understanding of how overweight children experience and interact with their environment is critical. Further research is needed to examine the mechanisms by which parent distress and peer victimization impact the development of depressive symptoms in overweight children, including coping and support strategies that may buffer these children against the development of depressive symptoms and ultimately lower QOL.
David M. Janicke, Kristen K. Marciel, Lisa M. Ingerski, et al. Impact of Psychosocial Factors on Quality of Life in Overweight Youth. Obesity Research;15(7): 1799-1807 (July 2007). [Correspondence: David M. Janicke, University of Florida, PO Box 100165, Gainesville, FL 32610-01655. E-mail: email@example.com.]
In our society and culture, where thinness marks success and happiness, almost every man, woman, and child has experienced issues with weight, self-image, and body shape. Whereas the majority of research on eating disorders has emphasized women, men are known to suffer from such illnesses. Like many other professional athletes, professional cyclists are the subjects of media scrutiny and great attention is placed on a riders weight. The sport of cycling may impose too great an emphasis on attaining a low body weight and lean body structure to be successful. In turn, some cyclists may develop a pathological emphasis on body form and food, leading to disordered eating patterns. The purpose of this study was to determine the prevalence of subclinical disordered eating behaviors among male cyclists, whether male cyclists self-report having an eating disorder, and whether male cyclists meet the daily recommendations for the major food groups according to the Dietary Guidelines for Americans.
Cyclists were recruited from an international pool of professional, university, and club racing programs through electronic means of flyer distribution. Those interested in participating completed a set of eating behavior questionnaires. Inclusion criteria included training a minimum of 5 hours on a bicycle each week throughout the year; have participated in cycling for no less than 1 year; and, if applicable, be actively competing. The control group consisted of male student volunteers from the University of Colorado at Colorado Springs. Male control participants were excluded from the study if they rode a bicycle more than three times a week for exercise or commuting.
The Eating Attitudes Test-26 (EAT-26), Survey of Eating Disorders Among Cyclists (SEDAC), and a nutrition questionnaire were completed by the study participants. The EAT-26 is a 26-item survey that is widely used to identify disturbed eating patterns and pathological concerns with food intake and weight. The three subfactors of the EAT-26 (that is, dieting [I], bulimia and food preoccupation [II], and oral control [III]) were used to distinguish differences in overall EAT-26 scores between the male cyclists and male control subjects. The SEDAC, like the Survey of Eating Disorders Among Athletes, is a 33-item questionnaire to identify self-reported eating disturbances, sport-related aspects contributing to the disorder, and the perceived incidence of eating disorders within the sport. The Dietary Guidelines for Americans daily food group serving size.
A group of 61 male cyclists was evaluated against 63 noncycling men. The self-reported mean age and mean weight of the cyclists and noncycling men was 31.6±10.4 and 23±6.3 years and 72.5±7.6 and 80.5±16.1 kg, respectively. Male cyclists, scoring higher, showed a significant difference on the overall EAT-26 scores, the dieting (subfactor I) subfactor and the bulimia and food preoccupation (subfactor II) subfactor; however, no significant difference was detected on the oral control subfactor (subfactor III) compared to the noncycling control group.
One explanation for these findings may be that cyclists are known to put great emphasis on excelling in competition and may accept the belief that becoming lighter will make them faster and more successful. Scores surpassing 20 on EAT-26 have been associated with atypical eating habits and weight concerns. Twelve of the male cyclists met or exceeded a score of 20 on the EAT-26, with a mean score of 28±4. Of these 12 cyclists, five self-reported having an eating disorder. These findings suggest that male cyclists may not know how to effectively identify an eating disorder and may perceive their own eating habits as normal, and not pathological. It is also possible that EAT-26, a screening tool, is not sensitive enough to identify male cyclists with eating disorder behaviors.
Only 18 cyclists out of 60 reported that eating disorders are not common in cycling, whereas 28 cyclists believed that eating disorders are somewhat common in cycling. These results suggest that more education in identifying pathological eating habits is needed among male cyclists.
Significant differences were observed between the dieting and bulimia and food preoccupation subfactors and, thus, the overall EAT-26 scores among male cyclists and the control group. Results from the SEDAC revealed that about half of the male cyclists who scored at or above 20 on the EAT-26 did not self-report having an eating disorder, suggesting that they may not know how to identify disordered eating habits. Because 18 cyclists believed that eating disorders were not common in cycling, greater emphasis needs to be placed on educating male cyclists about pathological eating behaviors. A self-reported nutrition questionnaire showed that cyclists may not meet their high energy needs and can be at a heightened danger for nutritional deficiencies as well as eating disorders. Although the issue of eating disorders among male cyclists has not been examined thoroughly, these results found that male cyclists may be at an amplified risk for having disordered eating behaviors; however, more in-depth study is required to make such a definite conclusion. Successive research on male cyclists should use various measures to address the prevalence of disordered eating in a larger sample size and quantify energy balance.
S Riebl, A Subudhi, J Broker, et al. The Prevalence of Subclinical Eating Disorders among Male Cyclists. JADA;107(7) (July 2007). [Correspondence: Shaun K. Riebl, MS, University of Colorado at Colorado Springs, Biology Department, 1420 Austin Bluffs, Colorado Springs, CO 80933.]
Amenorrhea is a known risk factor for osteopenia, and it occurs with weight loss in persons with anorexia nervosa (AN). Women with AN are at high risk of fractures and severe osteoporosis at menopause. Studies of the efficacy of hormone therapy or oral contraceptives in increasing the bone mass of women with AN have not consistently shown positive results.
Some studies of indexes of bone turnover in women with AN have found an uncoupling of bone homeostasis, characterized by a decrease in osteoblastic function (bone formation) and an increase in osteoclastic function (bone resorption), although results have been inconsistent. The mechanisms by which bone homeostasis is disrupted and recovered in women with AN are poorly understood. Osteocacalcin and N-telopeptide (NTX) are established biochemical markers of bone formation and resorption, respectively.
A longitudinal study was performed in which researchers studied women with AN before and after their weight was normalized. They then compared them with healthy female control subjects and a previously studied reference population to better understand the changes in bone mineral density (BMD) and the mechanism of recovery.
Investigators studied 28 patients with AN and 11 control subjects. In addition, they compared data with those from 30 reference control subjects. Patients were women with AN who were hospitalized for treatment. All met DSM-IV criteria for AN. Patients had a mean (±SD) length of illness of 98.0 ± 59.4 months. The patients with AN were 18 to 35 years at hospital admission. The 11 health control subjects did not have significant medical or psychiatric histories, and were matched with patients according to age and percentage of ideal body weight (IBW) range after recovery (90% to 100% IBW).
Patients were evaluated at the initiation of hospitalization for history of eating disorder and previous treatment (age at onset of AN, prior treatment type and duration, lowest and highest adult body mass index (BMI), and menstrual history), current symptoms of eating disorder, general activity, and nutritional profile. A full medical history was taken, and a physical examination was performed. Venous blood and urine samples were taken for hormone profile analysis. Patients were interviewed monthly to assess menstrual status. Each healthy control subject completed a medical questionnaire designed to assess general medical and menstrual history and was given a brief physical examination. Healthy controls were also given a take-home ovulation test kit to confirm ovulatory cycles and were asked to keep records of menstrual periods. All studies were done during the follicular phase of the menstrual cycle in menstruating subjects.
All patients underwent an inpatient, behavioral weight-gain treatment with cognitive, supportive, family, nutritional, and psychoeducational group elements aimed at restoring weight to a minimum of 90% IBW. The weight-gain phase of treatment was followed by a 4 to 6 week period of weight maintenance with increasing independence and transition to outpatient care. Mean caloric intake on discharge was 2600 kcal. Serum osteocalcin was measured. Estradiol, follicle-stimulating hormone, NTX, and luteinizing hormone (LH) were also measured. Total-body dual-energy X-ray absorptiometry (DXA) was used to measure bone mass and bone density.
Anorexic patients experienced significant percentage increases in BMD from admission until recovery of 90% ideal body weight, achieved over 2.2 months. NTX concentrations were higher in patients with AN at admission than in healthy control subjects and in reference control subjects. In weight-recovered subjects with AN, osteocalcin increased, whereas NTX remained elevated. A decrease in NTX occurred only in the subgroup of subjects who regained menses with weight recovery.
Nutritional rehabilitation induces a powerful anabolic effect on bone. However, a fall of NTX and a shift from the dominant resorptive state, which researchers postulate involves full recovery, may involve a hormonal mechanism and require a return of menses.
J. Dominguez, L. Goodman, S. Gupta, et al. Treatment of anorexia nervosa is associated with increases in bone mineral density, and recovery is a biphasic process involving both nutrition and return of menses. Am J Clin Nutr;86:92-99 (July, 2007). [Correspondence: MP Warren, Columbia University, College of Physicians and Surgeons, Department of Obstetrics and Gynecology, 622 West 168th Street, PH 16-128, New York, NY 10032. E-mail: firstname.lastname@example.org.]
Binge-eating disorder (BED) is a commonly occurring syndrome that is characterized by recurrent uncontrolled consumption of large amounts of food. Although obesity is not required for the diagnosis of BED, treatment samples are almost uniformly obese. Treatment for BED includes various forms of group and/or individual psychotherapy, medication, or combined medication and psychotherapy. In general the studies using these treatment modalities have reported short-term effects on binge eating. There have been few controlled studies of the long-term effects of treatment for BED on binge eating and on weight. Therefore, a recent study from the New York State Psychiatric Institute assessed the long-term effects of group behavior treatment plus individual cognitive behavioral therapy (CBT) and/or fluoxetine in BED patients.
A total of 116 individuals were randomized to an initial five-month trial and were followed up over two years. All subjects received group behavioral weight control treatment. Within each behavioral weight control group, approximately one half of subjects were assigned to fluoxetine and one half to placebo. In addition, approximately 50% of the subjects were randomly assigned to receive individual CBT. Assessments, including binge frequency, weight, and self-report measures, were administered at pre-treatment, post-treatment, and approximately 6, 12, 18, and 24 months after initial treatment. Some of the tools used included the Beck Depression Inventory, the Body Shape Questionnaire, the Binge Eating Scale, the Brief Symptom Inventory, and the Three-Factor Eating Questionnaire.
Of the subjects, 78% were female and 77% were white. Across treatment groups, there was overall improvement over 29 months in binge frequency and in binge abstinence. The odds of binge abstinence two years post-treatment were 1.373 times the odds of binge abstinence immediately post-treatment. There was no significant change in weight over the two-year period. Subjects who received individual CBT had lower binge frequency over the two-year follow-up period than patients who had not received individual CBT. Similarly, CBT was associated with increased rates of binge abstinence. There were no main effects of treatment assignment on weight over the follow-up period. There was a significant advantage for fluoxetine assignment over the follow-period on depressive symptoms.
This study begins to address the need for investigation of the long-term maintenance of change after treatment in obese patients with BED. The findings provide support for the ideas that short-term treatment may confer long-term benefit and that not all treatments are equivalent in the benefits they offer. Further studies of the long-term course of BED with and without treatment are obviously needed.
Michael J. Devlin, Juli A. Goldfein, Eva Petkova, et al. Cognitive Behavioral Therapy and Fluoxetine for Binge Eating Disorder: Two-year Follow-up. Obesity Research; 15(7): 1702-1709 (July 2007). [Correspondence: Michael J. Devlin, New York State Psychiatric Institute, Unit 116, 1051 Riverside Drive, New York, NY 10032. E-mail: email@example.com.]
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