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Background: Polyunsaturated fatty acids (PUFAs) are associated with protection from obesity-related phenotypes in adults; however, the relation between reported intake of PUFAs with body-composition outcomes in children remains unknown. Objective: Our objective was to examine how self-reported intakes of PUFAs, including total, n–6 (ω-6), and n–3 (ω-3) PUFAs and ratios of n–6 to n–3 PUFAs and PUFAs to saturated fatty acids (SFAs), are associated with measures of adiposity and lean mass (LM) in children. We hypothesized that higher self-reported intakes of PUFAs and the ratio of PUFAs to SFAs would be positively associated with LM and negatively associated with total adiposity. Methods: Body composition and dietary intake were measured in a racially diverse sample of 311 children (39% European American, 34% African American, and 27% Hispanic American) aged 7–12 y. Body composition and abdominal fat distribution were measured by dual-energy X-ray absorptiometry and computed tomography scans, respectively. Self-reported dietary intakes (including total PUFAs, n–3 PUFAs, n–6 PUFAs, and SFAs) were assessed by using two 24-h recalls. Independent-sample t tests and multiple linear regression analyses were conducted. Results: Total PUFA intake was positively associated with LM (P = 0.049) and negatively associated with percentage of body fat (%BF; P = 0.033) and intra-abdominal adipose tissue (IAAT; P = 0.022). A higher ratio of PUFAs to SFAs was associated with higher LM (P = 0.030) and lower %BF (P = 0.028) and IAAT (P = 0.048). Intakes of n–3 and n–6 PUFAs were positively associated with LM (P = 0.017 and P = 0.021, respectively), and the ratio of n–6 to n–3 PUFAs was negatively associated with IAAT (P = 0.014). All results were independent of biological, environmental, and genetic covariates. Conclusions: Our results show that a higher self-reported intake of PUFAs and a higher ratio of PUFAs to SFAs are positively associated with LM and negatively associated with visceral adiposity and %BF in a healthy cohort of racially diverse children aged 7–12 y. This trial was registered at clinicaltrials.gov as {"type":"clinical-trial","attrs":{"text":"NCT00726778","term_id":"NCT00726778"}}NCT00726778.

INTRODUCTION: Using Jackson Heart Study (JHS) data, we assessed the association between perceived psychosocial stressors and metabolic syndrome (MetS) severity in African American adults. METHODS: Participants included 3,870 African American JHS participants aged 21 to 95 years (63.1% women; mean age 53.8± 13.0). Psychosocial stressors assessed included: major life events (MLEs); global stress; and weekly stress inventory. Each stress measure was classified into tertiles (low, medium, and high). Associations of psychosocial stressors with a sex- and race/ethnic-specific MetS severity Z-score were examined after adjustment for demographics and MetS risk factors (i.e., nutrition, physical activity, smoking status, and alcohol consumption). RESULTS: Independent of lifestyle factors, participants who reported high (versus low) perceived global stress and MLEs had significantly greater MetS severity (p=0.0207 and p=0.0105, respectively). Weekly stress was not associated with MetS severity. Compared to men, women reported significantly higher global stress and MLEs (p

The focus of this commentary is Nettle et al.'s insurance hypothesis linking food insecurity to a high body mass index (BMI). We discuss how the relationship between race/ethnicity and obesity in the United States is consistent with this hypothesis, then present potential ways forward to elucidate the validity of this hypothesis in humans through rigorous controlled trials.

Background: Breakfast is associated with lower body weight in observational studies. Public health authorities commonly recommend breakfast consumption to reduce obesity, but the effectiveness of adopting these recommendations for reducing body weight is unknown. Objective: We tested the relative effectiveness of a recommendation to eat or skip breakfast on weight loss in adults trying to lose weight in a free-living setting. Design: We conducted a multisite, 16-wk, 3-parallel-arm randomized controlled trial in otherwise healthy overweight and obese adults [body mass index (in kg/m2) between 25 and 40] aged 20–65 y. Our primary outcome was weight change. We compared weight change in a control group with weight loss in experimental groups told to eat breakfast or to skip breakfast [no breakfast (NB)]. Randomization was stratified by prerandomization breakfast eating habits. A total of 309 participants were randomly assigned. Results: A total of 283 of the 309 participants who were randomly assigned completed the intervention. Treatment assignment did not have a significant effect on weight loss, and there was no interaction between initial breakfast eating status and treatment. Among skippers, mean (±SD) baseline weight-, age-, sex-, site-, and race-adjusted weight changes were −0.71 ± 1.16, −0.76 ± 1.26, and −0.61 ± 1.18 kg for the control, breakfast, and NB groups, respectively. Among breakfast consumers, mean (±SD) baseline weight-, age-, sex-, site-, and race-adjusted weight changes were −0.53 ± 1.16, −0.59 ± 1.06, and −0.71 ± 1.17 kg for the control, breakfast, and NB groups, respectively. Self-reported compliance with the recommendation was 93.6% for the breakfast group and 92.4% for the NB group. Conclusions: A recommendation to eat or skip breakfast for weight loss was effective at changing self-reported breakfast eating habits, but contrary to widely espoused views this had no discernable effect on weight loss in free-living adults who were attempting to lose weight. This trial was registered at clinicaltrails.gov as {"type":"clinical-trial","attrs":{"text":"NCT01781780","term_id":"NCT01781780"}}NCT01781780.

Background: Hypertension and dyslipidemia have traditionally been associated with dietary sodium and fat intakes, respectively; however, they have recently been associated with the consumption of added sugars in adults and older adolescents, but there is no clear indication of how early in the life span this association manifests. Objective: This study explored the cross-sectional association between added sugar (sugars not naturally occurring in foods) consumption in children, blood pressure (BP), and fasting blood lipids [triglycerides and total, low-density lipoprotein, and high-density lipoprotein (HDL) cholesterol]. Design: BP, blood lipids, and dietary intakes were obtained in a multiethnic pediatric sample aged 7–12 y of 122 European American (EA), 106 African American (AA), 84 Hispanic American (HA), and 8 mixed-race children participating in the Admixture Mapping of Ethnic and Racial Insulin Complex Outcomes (AMERICO) study—a cross-sectional study conducted in the Birmingham, AL, metro area investigating the effects of racial-ethnic differences on metabolic and health outcomes. Multiple regression analyses were performed to evaluate the relations of added sugars and sodium intakes with BP and of added sugars and dietary fat intakes with blood lipids. Models were controlled for sex, race-ethnicity, socioeconomic status, Tanner pubertal status, percentage body fat, physical activity, and total energy intake. Results: Added sugars were positively associated with diastolic BP (P = 0.0462, β = 0.0206) and serum triglycerides (P = 0.0206, β = 0.1090). Sodium was not significantly associated with either measure of BP nor was dietary fat with blood lipids. HA children had higher triglycerides but lower added sugar consumption than did either the AA or EA children. The AA participants had higher BP and HDL but lower triglycerides than did either the EA or HA children. Conclusions: These data suggest that increased consumption of added sugars may be associated with adverse cardiovascular health factors in children, specifically elevated diastolic BP and triglycerides. Identification of dietary factors influencing cardiovascular health during childhood could serve as a tool to reduce cardiovascular disease risk. This trial was registered at clinicaltrials.gov as {"type":"clinical-trial","attrs":{"text":"NCT00726778","term_id":"NCT00726778"}}NCT00726778.

OBJECTIVES: In this study, data from the Jackson Heart Study (JHS) were used to assess the independent associations between objective socioeconomic status (OSS) and subjective social status (SSS) with metabolic syndrome (MetS) severity and MetS indicators in African American (AA) adults at baseline and eight years later. METHODS: Participants included 3870 AA participants (63.1% women; mean age 53.8 ± 13.0, age range 35–84 years). OSS was assessed using annual household income and years of school completed. SSS was measured with the MacArthur Scale, using two 10-rung “ladders” with U.S. society and the individual's community as referent groups for their perceived social rank. Associations of OSS and SSS with a sex- and race/ethnic-specific MetS severity Z-score were examined after adjustment for demographics and MetS risk factors (i.e., nutrition, physical activity, smoking status, and alcohol consumption) at baseline and 8-year follow-up. RESULTS: Independent of OSS, demographic, and lifestyle factors, individuals who placed themselves on lower rungs of a visual ladder depicting relative social standing in society had more severe metabolic syndrome at baseline but not 8-years later (P = 0.0123 and P = 0.3248, respectively). The components of MetS driving the relationship between US-level SSS and MetS severity at baseline were waist circumference and triglyceride levels, as waist circumference and triglycerides at baseline were inversely associated with US-level SSS (P = 0.0124 and P = 0.0074, respectively). OSS components, including measures of income and education, were both independently associated with MetS severity at baseline (P

Objective: To examine and compare the relationships among diet, physical activity, and adiposity between home-schooled children (HSC) and traditionally schooled children (TSC). Design and Methods: Subjects were HSC (n 547) and TSC (n 548) aged 7-12 years old. Dietary intakes were determined via two 24-h recalls and physical activity was assessed with 7 days of accelerometry. Fat mass (FM), trunk fat, and percent body fat (%BF) were measured by dual-energy X-ray absorptiometry (DXA). Results: Relative to HSC, TSC demonstrated significantly higher BMI percentiles, FM, trunk fat, and %BF; consumed 120 total kilocalories more per day; and reported increased intakes of trans fats, total sugar, added sugars, calcium, and lower intakes of fiber, fruits, and vegetables (P

Both subjective and objectively measured social status has been associated with multiple health outcomes, including weight status, but the mechanism for this relationship remains unclear. Experimental studies may help identify the causal mechanisms underlying low social standing as a pathway for obesity. Our objective was to investigate the effects of experimentally manipulated social status on ad libitum acute dietary intakes and stress-related outcomes as potential mechanisms relating social status and weight. This was a pilot feasibility, randomized, crossover study in Hispanic young adults (n=9; age 19-25; 67% female; BMI ≥18.5 and ≤30kg/m(2)). At visit 1, participants consumed a standardized breakfast and were randomized to a high social status position (HIGH) or low social status position (LOW) in a rigged game of Monopoly™. The rules for the game differed substantially in terms of degree of 'privilege' depending on randomization to HIGH or LOW. Following Monopoly™, participants were given an ad libitum buffet meal and energy intakes (kcal) were estimated by pre- and post-weighing foods consumed. Stress-related markers were measured at baseline, after the game of Monopoly™, and after lunch. Visit 2 used the same standardized protocol; however, participants were exposed to the opposite social status condition. When compared to HIGH, participants in LOW consumed 130 more calories (p=0.07) and a significantly higher proportion of their daily calorie needs in the ad libitum buffet meal (39% in LOW versus 31% in HIGH; p=0.04). In LOW, participants reported decreased feelings of pride and powerfulness following Monopoly™ (p=0.05) and after their lunch meal (p=0.08). Relative to HIGH, participants in LOW demonstrated higher heart rates following Monopoly™ (p=0.06), but this relationship was not significant once lunch was consumed (p=0.31). Our pilot data suggest a possible causal relationship between experimentally manipulated low social status and increased acute energy intakes in Hispanic young adults, potentially influenced by decreased feelings of pride and powerfulness. Increased energy intake over time, resulting in positive energy balance, could contribute to increased risk for obesity, which could partially explain the observed relationship between low social standing and higher weight. Larger and longitudinal studies in a diverse sample need to be conducted to confirm findings, increase generalizability, and assess whether this relationship persists over time.

Although differences in body composition parameters among African American (AA), Hispanic American (HA) and European American (EA) children are well documented, the factors underlying these differences are not completely understood. Environmental and genetic contributors have been evaluated as contributors to observed differences. This study evaluated the extent to which African or European ancestral genetic background influenced body composition and fat distribution in 301 peripubertal AA (n = 107), HA (n = 79) and EA (n = 115) children aged 7-12.Estimates of African admixture (AFADM) and European admixture (EUADM) were obtained for every subject using 142 ancestry informative DNA markers. Dual energy X-ray absorptiometry and computed tomography scanning were used to determine body composition and abdominal fat distribution, respectively. Multiple regression models were conducted to evaluate the contribution of admixture estimates to body composition and fat distribution.Greater AFADM was associated with lower fat mass (P = 0.0163), lower total abdominal adipose tissue (P = 0.0006), lower intra-abdominal adipose tissue (P = 0.0035), lower subcutaneous abdominal adipose tissue (P = 0.0115) and higher bone mineral content (BMC) (P = 0.0253), after adjusting for socio-economic status, sex, age, height, race/ethnicity and pubertal status. Greater EUADM was associated with lower lean mass (LM) (P = 0.0056).These results demonstrate that ancestral genetic background contributes to racial/ethnic differences in body composition above and beyond the effects of racial/ethnic classification and suggest a genetic contribution to total body fat accumulation, abdominal adiposity, LM and BMC.

Background Accumulating evidence implicates diet quality in childhood as playing a significant role in adult cardiometabolic health. Polyunsaturated fatty acids (PUFAs) of the n–6 (ω-6) and n–3 (ω-3) series contribute unique protective effects against cardiometabolic disease. As such, the ratio between n–6 and n–3 PUFAs is a dietary metric of interest in the early life span, although an optimum intake ratio has yet to be determined. Objective This cross-sectional study assesses relations between the ratio of total n–6:n–3 PUFA intake and cardiometabolic risk factors in a racially diverse sample of children (n = 191) from the Admixture Mapping of Ethnic and Racial Insulin Complex Outcomes (AMERICO) study. Methods Outcome measures included waist circumference, lipid concentrations, fasting glucose, and two 24-h dietary recalls from boys and girls aged 7–12 y who self-reported as European American (n = 81), African American (n = 55), or Hispanic American (n = 55). Linear regression analyses were used to assess associations between predictors of interest and outcomes after adjusting for covariates. Results PUFA intake reflected in the n–6:n–3 ratio was inversely associated with concentrations of total and LDL cholesterol [β ± SE: −0.359 ± 0.107 (P = 0.001) and −0.189 ± 0.069 (P = 0.007), respectively]. Exploratory analyses showed that the intake of total n–6 PUFAs was not significantly predictive of any cardiometabolic risk factor assessed, whereas total n–3 PUFA intake was positively associated with concentrations of HDL cholesterol (β ± SE: 0.114 ± 0.042; P = 0.007). Conclusions Results suggest that the effect of n–6 and n–3 PUFA intake reflected in the ratio may be largely driven by n–3 PUFAs in reducing 2 lipid cardiometabolic risk factors among this multiethnic cohort of children. Until an ideal intake ratio is determined, nutritional counseling should focus on meeting recommended levels of both n–3 and n–6 PUFAs in order to establish beneficial childhood dietary patterns that may positively influence adult cardiometabolic health.

Objective To identify biological and psychosocial factors associated with dropout in a multidisciplinary behavioral intervention in obese adolescents.Methods A total of 183 adolescents (15.4±1.6 years), pubertal (Tanner stage 3 or 4) and obese (34.7±4.0kg/m2), were enrolled in a 12-week behavioral intervention, which included clinical consultations (monthly), nutritional and psychological counseling (once a week), and supervised aerobic training (three times/week). The studied variables were weight, height, body mass index, body composition (skinfold), cardiorespiratory fitness (direct gas analysis), blood lipids and self-reported symptoms of eating disorders (bulimia, anorexia and binge eating), anxiety, depression, body image dissatisfaction and quality of life. Statistical analysis included binary logistic regression and independent t-tests.Results Of the adolescents, 73.7% adhered to the program. The greatest chance for dropout was observed among adolescents older than 15 years (odds ratio of 0.40; 95%CI: 0.15-0.98), with more anorexia symptoms (odds ratio of 0.35; 95%CI: 0.14-0.86) and hypercholesterolemia (odds ratio of 0.40; 95%CI: 0.16-0.91) at baseline.Conclusion Older adolescents, with more symptoms of eating disorders and total cholesterol have less chance to adhere to multidisciplinary treatments. Objetivo Identificar os fatores biológicos e psicossociais associados à desistência de uma intervenção multidisciplinar comportamental em adolescentes obesos.Métodos Foram selecionados para participar das 12 semanas de intervenção 183 adolescentes (15,4±1,6 anos), púberes (Tanner 3 ou 4) e obesos (34,7±4,0 kg/m2). A intervenção incluiu consultas clínicas (mensal), aconselhamento nutricional e psicológico (uma vez/semana), e treinamento aeróbio supervisionado (três vezes/semana). As variáveis estudadas foram peso, altura, índice de massa corporal, composição corporal (dobras cutâneas), aptidão cardiorrespiratória (análise direta de gases), perfil lipídico e sintomas autorrelatados de transtornos alimentares (bulimia, anorexia e compulsão alimentar), ansiedade, depressão, insatisfação com a imagem corporal e qualidade de vida. A análise estatística incluiu regressão logística binária e teste tde Student independente.Resultados Aderiram ao programa 73,7% dos adolescentes. A maior chance de desistência foi observada entre aqueles com mais de 15 anos (odds ratiode 0,40; IC95%: 0,15-0,98), com mais sintomas de anorexia (odds ratio de 0,35; IC95%: 0,14-0,86) e com hipercolesterolemia (odds ratio de 0,40; IC95%: 0,16-0,91) no início do estudo.Conclusão Adolescentes mais velhos, com mais sintomas de transtornos alimentares e de níveis de colesterol total, têm menor chance de aderir a tratamentos multidisciplinares.

Disentangling the etiology of pediatric obesity continues to challenge researchers. Due to rapid growth and development, changes in the hormonal milieu, increased autonomy in feeding practices and greater interactions with environmental factors, adolescence is a particularly important period for the determination of body composition trajectories and the relationship to current and future obesity outcomes. A plethora of studies have focused on excess energy consumption and physical inactivity as they relate to weight and fat gain in adolescence. Although these "Big Two" have an impact, the increasing trends in pediatric obesity are not accounted for solely by increased energy intake and decreased physical activity. Indeed, under similar conditions of energy balance, inter-individual variation in fat accumulation has been consistently noted. It is becoming more evident that additional factors may contribute independently and/or synergistically to the increase in obesity. Such factors include (but are not limited to) metabolic programming in utero and in early childhood, the hormonal environment, endocrine disruptors, parental feeding practices, and the built environment. Our objective, therefore, is to investigate possible factors, particularly in adolescence that contributes to the increase in pediatric obesity beyond "The Big Two".

GWAS studies have been successful in finding genetic determinants of obesity. To translate discovered genetic variants into new therapies or prevention strategies, molecular or physiological mechanisms need to be discovered. One strategy is to perform data mining of data sets with detailed phenotypic data, such as those present in dbGAP (database of Genotypes and Phenotypes) for hypothesis generation. We propose a novel technique that combines the power and computational efficiency of existing Bayesian Network (BN) learning algorithms with the statistical rigor of Structural Equation Modeling (SEM) to produce an overall system that searches the space of potential networks and evaluates promising candidates using standard SEM model selection criteria. We demonstrate our method using the analysis of a candidate SNP data set from the AMERICO sample, a multi-ethnic cross-sectional cohort of roughly three hundred children with detailed obesity-related phenotypes. We demonstrate our approach by showing genetic mechanisms for three obesity-related SNPs.

Obesity prevalence among African American (AA) girls is higher than that in other groups. Because typical energy-restriction obesity treatment strategies have had limited success, alterations in macronutrient composition may effectively improve metabolic outcomes in this population and affect future body composition trajectories. The objective was to evaluate the efficacy of a moderately restricted carbohydrate (CHO) versus a standard CHO diet on weight/fat loss and metabolic parameters in overweight/obese AA girls ages 9 to 14 years.A total of 26 AA girls (ranging from 92nd body mass index percentile and above) were assigned to either a reduced- (SPEC: 42% energy from CHO, n = 12) or a standard- (STAN: 55% of energy from CHO, n = 14) CHO diet (protein held constant) for 16 weeks. All of the meals were provided and clinically tailored to meet the estimated energy requirements (resting energy expenditure × 1.2 in eucaloric phase and resting energy expenditure × 1.2 - 1000 kcal in energy deficit phase). The first 5 weeks encompassed a eucaloric phase evaluating metabolic changes in the absence of weight change. The subsequent 11 weeks were hypocaloric (1000 kcal/day deficit) to promote weight/fat loss. Meal tests were performed during the eucaloric phase for metabolic analyses. Dual-energy x-ray absorptiometry was used to evaluate body composition.Both groups experienced reductions in weight/adiposity, but the difference did not reach significance. The solid meal test indicated improved glucose/insulin homeostasis on the SPEC diet up to 3 hours postingestion. In addition, significantly lower triglycerides (P 0.001) were observed on the SPEC diet.Dietary CHO reduction favorably influences metabolic parameters but did not result in greater weight/fat loss relative to a standard diet in obese AA girls. Future research is needed to determine long-term effectiveness of a reduced CHO diet on glucose and insulin homeostasis and how it may apply to weight maintenance/fat loss during development alone and/or in combination with additional weight loss/metabolic improvement strategies.

Parental feeding practices have been associated with children's weight status, but results have been inconsistent across populations. Research is needed to elucidate the relationship between parental feeding practices and adiposity in diverse populations. The present study tested if: (1) parental feeding practices differed by race/ethnicity, (2) parental pressure to eat and parental restriction were associated with adiposity levels, and (3) to investigate the relationship between parental feeding practices and/or child adiposity with socioeconomic status (SES). Structural equations modeling was conducted to test the model in 267 children aged 7-12 years self-identified as African American (AA), European American (EA), or Hispanic American (HA) from economically diverse backgrounds. Dual energy X-ray absorptiometry and computed tomography scanning were used to determine body composition and abdominal fat distribution, respectively. Parental restriction was a significant predictor of child adiposity while parental pressure to eat had an inverse relationship with child adiposity. HA parents reported significantly higher levels of restriction and pressure to eat, whereas EA parents reported the lowest. SES was positively associated with child adiposity and inversely related to parental restriction and pressure to eat. Thus, parental feeding practices differ across racial/ethnic groups and SES and may contribute to population differences in child adiposity.

Objective The objective was to determine if calcium intake was associated with resting energy expenditure (REE) and body fat in children after accounting for ancestral genetic background. Study design Participants included 315 children. REE, body composition, and dietary calcium were assessed by indirect calorimetry, dual-energy x-ray absorptiometry, and 24-hour recalls, respectively. Structural equations modeling assessed the relationships among REE, calcium intake, and body fat. Results There were positive associations between calcium intake and REE (P < .01) and between REE and total body fat (P < .0001). There was indirect effect of calcium intake on total body fat (P < .01). There were positive associations between calcium intake and REE (P < .01), and a trend toward an association of calcium intake and total body fat (P = .065) among boys only, whereas the only significant relationship among girls was an association of REE on total body fat (P < .0001). Conclusions REE was associated with calcium intake and mediated a relationship between calcium intake and total body fat. These findings suggest calcium intake may play a role in fat accumulation and energy balance through its effects on REE, especially in boys. (J Pediatr 2010;157:473-8).

Genome-wide Association Studies (GWAS) have resulted in many discovered risk variants for several obesity-related traits. However, before clinical relevance of these discoveries can be achieved, molecular or physiological mechanisms of these risk variants needs to be discovered. One strategy is to perform data mining of phenotypically-rich data sources such as those present in dbGAP (database of Genotypes and Phenotypes) for hypothesis generation. Here we propose a technique that combines the power of existing Bayesian Network (BN) learning algorithms with the statistical rigor of Structural Equation Modeling (SEM) to produce an overall phenotypic network discovery system with optimal properties. We illustrate our method using the analysis of a candidate SNP data set from the AMERICO sample, a multi-ethnic cross-sectional cohort of roughly three hundred children with detailed obesity-related phenotypes. We demonstrate our approach by showing genetic mechanisms for three obesity-related SNPs.