Television Viewing Is Not Predictive of BMI in Black and Hispanic Young Adult Females

Previous studies have observed that television (TV) viewing is predictive of obesity and weight gain. We examined whether the cross‐sectional association between TV viewing and BMI varied by racial/ethnic subgroups among young women in Wave III (collected in 2001–2002) of the National Longitudinal Study of Adolescent Health. We used multivariate linear regression to examine the relationship between TV viewing and BMI among 6,049 females while controlling for sociodemographic and health attributes. We stratified the sample by race/ethnicity to better understand the association between TV viewing and BMI across different groups. Black and Hispanic females had higher BMIs (black: 28.5 kg/m², Hispanic: 27.3 kg/m², white: 26.0 kg/m²) than white females, while black females reported higher numbers of hours spent watching TV (black: 14.7 h/week, Hispanic: 10.6 h/week, white: 11.2 h/week) when compared to their white and Hispanic peers. TV viewing was positively associated with BMI (β = 0.79, P = 0.003 for 8–14 vs. ≤7 h/week; β = 1.18, P = 0.01 for >14 vs. ≤7 h/week) independent of race/ethnicity, age, maternal education, history of pregnancy, parental obesity, and household income. However, in models stratified by race/ethnicity, increased TV viewing was associated with increased BMI only among white females; TV viewing was not predictive of higher BMI in black or Hispanic young adult females. Among black and Hispanic females, counseling to decrease TV viewing may be important but insufficient for promoting weight loss.     

Impact of Objective and Subjective Social Status on Obesity in a Biracial Cohort of Adolescents

Objective: To characterize the associations between socioeconomic status (SES), two levels of subjective social status (SSS), and adolescent obesity. Research Methods and Procedures: Cross‐sectional study of 1491 black and white adolescents attending public school in a suburban school district in Greater Cincinnati, Ohio. BMI ≥95th percentile derived from measured height and weight defined overweight. Students rated SSS on separate 10‐point scales for society and school. A parent provided information on parent education and household income for SES. Results: Although there were no sex differences in SES, black students were more likely to come from families with less well‐educated parents and lower incomes (p < 0.001). Black girls had the lowest societal SSS (p = 0.003), lowest school SSS (p = 0.046), and highest BMI (p < 0.001). Prevalence of overweight was highest among black girls (26.0%) and boys (26.2%), intermediate for white boys (17.2%), and least for white girls (11.6%). Logistic regression modeling revealed that parent education, household income, and school SSS were each associated with overweight. In a fully adjusted model, school SSS retained its association to overweight (odds ratio, 1.16; 95% CI, 1.06, 1.26) independent of SES. The association of school SSS was strongest among white girls, intermediate for white and black boys, and absent for black girls. Discussion: Perceptions of social stratification are independently associated with overweight. There were important racial and sex differences in the social status‐overweight association. SSS in the more immediate, local reference group, the school, had the strongest association to overweight.     

Weight Loss Surgery Eligibility According to Various BMI Criteria Among Adolescents

A BMI cutoff point at the 99th percentile for age and gender or at 40 kg/m² has been suggested for more aggressive treatment of adolescent obesity. The main objective of this study was to determine the proportion of adolescents eligible for weight loss surgery (WLS) based on various BMI cutoff points. Data was extracted from the electronic medical record database of an urban pediatric ambulatory care center over 4 years. National data were used to calculate BMI percentiles (Centers for Disease Control and Prevention (CDC), 2000). Eligibility for WLS was based on a BMI percentile criterion (≥99th percentile) or the adult WLS cutoff point (≥40 kg/m²). The sample consisted of 3,220 adolescents aged 12–17.9 years, of which 53% were female, 55% were of black race, and 17% of Hispanic ethnicity. Overall, 88 (3%) adolescents had a BMI ≥40 kg/m² and 236 (7%) had a BMI ≥99th percentile (P < 0.001). All adolescents with BMI ≥40 kg/m² had a BMI ≥99th percentile. A total of 159/2,007 (8%) of 12–14.9‐year olds had a BMI ≥99th percentile compared with 77/1,213 (6%) 15–17.9‐year olds (P = 0.10), whereas 43/2,007 (2%) of 12–14.9‐year olds had a BMI ≥40 kg/m² compared with 45/1,213 (4%) 15–17.9‐year olds (P = 0.003). In summary, a relatively large proportion of adolescents from a diverse urban population would qualify for WLS based on the percentile criterion. Fewer adolescents would be eligible based on the adult WLS criterion, and younger adolescents would be less likely to be eligible for WLS than older adolescents.     

Neighborhood risk factors for obesity

Objective: The goal of this study was to explore neighborhood environmental factors associated with obesity in a sample of adults living in a major U.S. metropolitan area. Research Methods and Procedures: This was a multi‐level study combining data from the U.S. Behavioral Risk Factor Surveillance System with data from the U.S. Census. A total of 15,358 subjects living in 327 zip code tabulation areas were surveyed between 1998 and 2002. The outcome was obesity (BMI >30), and independent variables assessed included individual level variables (age, education, income, smoking status, sex, black race, and Hispanic ethnicity), and zip code level variables (percentage black, percentage Hispanic, percentage with more than a high school education, retail density, establishment density, employment density, population density, the presence of a supermarket, intersection density, median household income, and density of fast food outlets). Results: After controlling for individual level factors, median household income [relative risk (RR) = 0.992; 95% confidence interval (CI) = 0.990, 0.994], population density (RR = 0.98; 95% CI = 0.972, 0.990), employment density (RR = 1.004; 95% CI = 1.001, 1.009), establishment density (RR = 0.981 95% CI = 0.964, 0.999), and the presence of a supermarket (RR = 0.893; 95% CI = 0.815, 0.978) were associated with obesity risk. Fast food establishment density was poorly associated with obesity risk. Discussion: Where one lives may affect obesity status. Given the influence of the presence of a supermarket on obesity risk, efforts to address food access might be a priority for reducing obesity.     

Maternal obesity is associated with younger age at obesity onset in U.S. adolescent offspring followed into adulthood

Objective: The objective was to test the hypothesis that maternal obesity is associated with younger age of offspring's obesity onset. Research Methods and Procedures: We used prospective, nationally representative, longitudinal data collected across Waves I (1995; 12 to 20 years), II (1996; 13 to 20 years), and III (2001; 18 to 28 years) of the National Longitudinal Study of Adolescent Health (N = 14,654; 49% female). Interval regression analysis was used to assess the association between maternal obesity and age at offspring's obesity onset (International Obesity Task Force BMI ≥30 equivalent age‐ and sex‐specific cut‐off points for adolescents and BMI ≥30 for young adults) using self‐reported heights and weights, adjusting for race/ethnicity, sex, parental education, and family income, accounting for complex sampling design. Results: The net effect of having an obese mother varied by race/ethnicity and was associated with a significantly earlier age at obesity onset (p = 0.0001) for whites [β= ?8.1 year, 95% confidence interval (CI), ?9.3; ?6.9)], blacks (β = ?10.8 years, 95% CI, ?12.4; ?9.2), Hispanics (β = ?7.0 years, 95% CI, ?9.2; ?4.8), and Asians (β = ?8.6 years, 95% CI, ?13.3; ?3.9). Earlier obesity onset (<18 years) was associated with increased severity at young adulthood (mean BMI, 36.0 ± 0.3 kg/m²) vs. onset after age 18 (mean BMI, 34.4 ± 0.2 kg/m²; p = 0.0001). There were no sex differences in the association of maternal obesity to age at obesity onset. Conclusions: Having an obese mother was associated with earlier age at obesity onset across all race/ethnic groups, particularly non‐Hispanic blacks. Early obesity onset has important health consequences because of its association with more severe adult obesity.     

Psychometric properties and construct validity of the Weight-Related Eating Questionnaire in a diverse population

This study evaluates the 16‐item, four‐factor Weight‐Related Eating Questionnaire (WREQ), which assesses theory‐based aspects of eating behavior, across diverse, nonclinical subgroups. A total of 621 men and women aged 18–81 years (34.3 ± 16.4) with a mean BMI of 25.7 ± 6.1 kg/m² (range 15.5–74.1 kg/m²) were recruited from general education classes at the University of Hawai'i, Manoa and an online survey panel of Hawai'i residents to complete a web‐based survey. Participants were predominantly white (23%), Asian/Asian‐mix (42%), or Native Hawaiian/Pacific Islander (18%). The WREQ's factor structure was successfully replicated by confirmatory factor analysis (CFA) for the entire sample and by weight status, gender, age, and race with strong internal consistency. Four‐week test‐retest reliability (n = 31) for the subscales was excellent with interclass correlations of 0.849–0.932. Tests of population invariance confirmed the generalizability of the WREQ across all subgroups having provided no evidence that the factor structure, factor loadings, or indicator intercepts varied significantly between the groups. Multivariate regression analyses showed that emotional eating was independently associated with BMI (β = 0.272, P < 0.001) as well as moderate‐ and long‐term weight change rates (weight gain) in young adults (β = 0.152, P = 0.042) and adults (β = 0.217, P = 0.001). Compensatory restraint was negatively associated with weight gain in adults (β = ?0.133, P = 0.039). Routine restraint and emotional eating were highest among dieters. All associations remained significant after accounting for gender, age, and race. The hypothesized WREQ measurement model demonstrated very good construct validity, confirming the unbiased generalizability of the WREQ measure across sex, age, race, and BMI subgroups, and excellent criterion‐related validity with respect to current BMI, weight change, and weight control status.     

School Programs and Characteristics and Their Influence on Student BMI: Findings from Healthy Passages

Background

Little is known about the contribution of school contextual factors to individual student body mass index (BMI). We set out to determine if school characteristics/resources: (1) are associated with student BMI; (2) explain racial/ethnic disparities in student BMI; and (3) explain school-level differences in student BMI.

Methods

Using gender-stratified multi-level modeling strategies we examined the association of school characteristics/resources and individual BMI in 4,387 5^th graders in the Healthy Passages Longitudinal Study of Adolescent Health. Additionally, we examined the association of race/ethnicity and individual BMI as well as the between-school variance in BMI before and after adding individual and school characteristics to test for attenuation.

Results

The school-level median household income, but not physical activity or nutrition resources, was inversely associated with female BMI (β = −0.12, CI: −0.21,−0.02). Neither school demographics nor physical activity/nutrition resources were predictive of individual BMI in males. In Black females, school characteristics attenuated the association of race/ethnicity and BMI. Individual student characteristics—not school characteristics/resources-reduced the between-school variation in BMI in males by nearly one-third and eliminated it in females.

Conclusions

In this cohort of 5^th graders, school SES was inversely associated with female BMI while school characteristics and resources largely explained Black/White disparities in female weight status. Between-school differences in average student weight status were largely explained by the composition of the student body not by school characteristics or programming.     

A 30‐year Follow‐up of the Effects of Child Abuse and Neglect on Obesity in Adulthood

Childhood maltreatment has been implicated as a risk factor for adult obesity. We describe the first prospective assessment of adult obesity in individuals with documented histories of childhood physical and sexual abuse and neglect and a matched comparison group in a 30‐year follow‐up. Using a prospective cohort design, children with court substantiated cases of physical and sexual abuse and neglect (ages 0–11 years) from a Midwest county during 1967–1971 (n = 410) were matched with children without histories of abuse or neglect on age, sex, race/ethnicity and approximate family social class (n = 303) and followed up and assessed at mean age 41. Outcome measures include BMI and obesity assessed in 2003–2004 as part of a medical status examination and interview. Childhood physical abuse predicted significantly higher BMI scores in adulthood (β = 0.14, P < 0.05), even controlling for demographic characteristics, cigarette smoking, and alcohol consumption (β = 0.16, P < 0.01). Childhood sexual abuse (β = 0.07, not significant) and neglect (β = 0.02, not significant) were not significant predictors of adult BMI scores. These results demonstrate the long‐term impact of childhood physical abuse on weight into adulthood and suggest that physically abused children may be at risk for other adverse health outcomes associated with increased weight. Health professionals need to understand this risk for physically abused children and researchers should identify and evaluate strategies for effective interventions.     

Ability to taste 6-n-propylthiouracil and BMI in low-income preschool-aged children

Background: Sensitivity to the bitter compound 6‐n‐propylthiouracil (PROP) is genetically mediated. Sensitivity to PROP has been associated with weight status in both adults and children. Objective: To determine whether there is an association between PROP sensitivity and BMI in low‐income children of diverse race/ethnicity, among whom there is a high prevalence of obesity. Methods and Procedures: Eighty‐one preschool‐aged children attending Head Start tasted a solution of 560 μmol/l PROP and reported whether it tasted “like water” or “like something else”. Mothers reported child's race, age, maternal education, maternal weight and height, child's reluctance to sample new foods via the Food Neophobia Scale (FNS), and child's dietary intake using a food frequency questionnaire. Child weight and height were measured. BMI was calculated and for children, expressed in z‐scores. Regression analyses were used to evaluate the relationship between child's PROP taster status and BMI z‐score, testing covariates child's age, gender, race, maternal education and BMI, and child's FNS score. Children's dietary intake was compared by PROP taster status. Results: PROP tasters, compared with nontasters, had significantly higher BMI z‐scores (0.99 (s.d. 1.24) vs. 0.03 (1.12), P = 0.004) and had a significantly higher prevalence of overweight (31.8% vs. 5.6%, P = 0.025), but demonstrated no differences in reported dietary intake. The most parsimonious model predicting the child's BMI z‐score included only maternal BMI and the child's PROP taster status (R ² = 22.3%). Discussion: A genetically mediated ability to taste bitter may contribute to obesity risk in low‐income, preschool‐aged children.     

Raised CRP levels in obese patients: symptoms of depression have an independent positive association

Background: Depression and obesity, the two common ailments of modern society, are associated with increased risk of coronary artery disease and raised C‐reactive protein (CRP) levels. Are the effects of depression and obesity related or do they influence CRP levels independently? Objective: In 493 consecutive patients presenting for obesity surgery, we explored the relationship between symptoms of depression and raised CRP levels after controlling for confounding factors. Methods and Procedures: Depression was measured using the Beck Depression Inventory (BDI). Confounding variables were age, gender, BMI, waist and hip measures, smoking and alcohol habits, medications, biochemical measures of the metabolic syndrome, and indirect measures of insulin resistance. General linear regression sought variables independently associated with CRP levels. Results: These patients had a BMI range from 31 to 91 kg/m², participants age ranged from 14 to 71 years, and 76% were women. The median CRP concentration was 7.7 mg/l (interquartile range: 3.9–14), 40% had an abnormally raised concentration (>10 mg/l). The mean BDI score was 17.0 ± 9.0, indicating symptoms of moderate depression. We found five independent factors associated with raised CRP levels. In order of strength of association, these were: higher BMI (β = 0.36, P < 0.001), female gender (β = ?0.19, P < 0.001), estrogen therapy (β = 0.18, P < 0.001), higher BDI score (β = 0.11, P = 0.01), and insulin resistance index (β = 0.11, P = 0.01), and with a combined R ² = 0.24, (P < 0.001). Discussion: In obese patients, symptoms of depression were associated with raised CRP levels after controlling for confounding variables. Obese women on estrogen therapy are at risk of high CRP levels.     

Waist Circumference,BMI, and Visceral Adipose Tissue in White Women and Women of African Descent

Although waist circumference (WC) is a marker of visceral adipose tissue (VAT), WC cut‐points are based on BMI category. We compared WC‐BMI and WC‐VAT relationships in blacks and whites. Combining data from five studies, BMI and WC were measured in 1,409 premenopausal women (148 white South Africans, 607 African‐Americans, 186 black South Africans, 445 West Africans, 23 black Africans living in United States). In three of five studies, participants had VAT measured by computerized tomography (n = 456). Compared to whites, blacks had higher BMI (29.6 ± 7.6 (mean ± s.d.) vs. 27.6 ± 6.6 kg/m², P = 0.001), similar WC (92 ± 16 vs. 90 ± 15 cm, P = 0.27) and lower VAT (64 ± 42 vs. 101 ± 59 cm², P < 0.001). The WC‐BMI relationship did not differ by race (blacks: β (s.e.) WC = 0.42 (.01), whites: β (s.e.) WC = 0.40 (0.01), P = 0.73). The WC‐VAT relationship was different in blacks and whites (blacks: β (s.e.) WC = 1.38 (0.11), whites: β (s.e.) WC = 3.18 (0.21), P < 0.001). Whites had a greater increase in VAT per unit increase in WC. WC‐BMI and WC‐VAT relationships did not differ among black populations. As WC‐BMI relationship did not differ by race, the same BMI‐based WC guidelines may be appropriate for black and white women. However, if WC is defined by VAT, race‐specific WC thresholds are required.     

Sexual Orientation Disparities in Weight Status in Adolescence: Findings From a Prospective Study

A growing number of studies among adult women have documented disparities in overweight adversely affecting lesbian and bisexual women, but few studies have examined sexual orientation–related patterns in weight status among men or adolescents. We examined sexual orientation group trends in BMI (kg/m²), BMI Z‐scores, and overweight using 56,990 observations from 13,785 adolescent females and males in the Growing Up Today Study (GUTS), a large prospective cohort of US youth. Participants provided self‐reported information from six waves of questionnaire data collection from 1998 to 2005. Gender‐stratified linear regression models were used to estimate BMI and BMI Z‐scores and modified Poisson regression models to estimate risk ratios for overweight, controlling for age and race/ethnicity, with heterosexuals as the referent group. Among females, we observed fairly consistently elevated BMI in all sexual orientation minority groups relative to heterosexual peers. In contrast, among males we documented a sexual‐orientation‐by‐age interaction indicating steeper increases in BMI with age from early‐to‐late adolescence in heterosexuals relative to sexual orientation minorities. Additional prospective research is needed to understand the determinants of observed sexual orientation disparities and to inform appropriate preventive and treatment interventions. The long‐term health consequences of overweight are well‐documented and over time are likely to exact a high toll on populations with elevated rates.     

Body mass index and depressive symptoms: instrumental‐variables regression with genetic risk score

The causal role of obesity in the development of depression remains uncertain. We applied instrumental‐variables regression (Mendelian randomization) to examine the association of adolescent and adult body mass index (BMI) with adult depressive symptoms. Participants were from the Young Finns prospective cohort study (n = 1731 persons, 2844 person‐observations), with repeated measurements of BMI and depressive symptoms (modified Beck's Depression Inventory). Genetic risk score of 31 single nucleotide polymorphisms previously identified as robust genetic markers of body weight was used as a proxy for variation in BMI. In standard linear regression analysis, higher adult depressive symptoms were predicted by higher adolescent BMI (B = 0.33, CI = 0.06–0.60, P = 0.017) and adult BMI (B = 0.47, CI = 0.32–0.63, P < 0.001). These associations were replicated in instrumental‐variables analysis with genetic risk score as instrument (B = 1.96, CI = 0.03–3.90, P = 0.047 for adolescent BMI; B = 1.08, CI = 0.11–2.04, P = 0.030 for adult BMI). The association for adolescent BMI was significantly stronger in the instrumented analysis compared to standard regression (P = 0.04). These findings provide additional evidence to support a causal role for high BMI in increasing symptoms of depression. However, the present analysis also demonstrates potential limitations of applying Mendelian randomization when using complex phenotypes.     

Predictors of attrition and weight loss in an adolescent weight control program

Objective: To evaluate demographic and psychosocial predictors of attrition and weight loss in a behaviorally based adolescent weight control trial. Methods and Procedures: Adolescents (N = 76) aged 13–16 years and 20–80% overweight (M = 60.56%, s.d. = 15.17%) received standard group‐based behavioral treatment as part of a randomized trial comparing different activity interventions for overweight adolescents. Anthropometric and psychosocial measures were obtained at baseline and after the 16‐week intervention. Results: Higher parent (P < 0.01) and adolescent BMI (P < 0.05) at baseline, as well as ethnic minority status (P < 0.05) were significantly associated with attrition in univariate analyses. Parent BMI remained the only significant predictor of attrition in multivariate analyses. BMI change for completers (N = 62) was highly variable, ranging from ?6.09 to +1.62 BMI units. Male gender (P < 0.01) was a significant predictor of reduction in BMI, whereas not being from an ethnic minority group (P < 0.05) and attendance at group sessions (P = 0.05) were associated with ≥5% absolute weight loss in multivariate analyses. Absolute weight loss during the first 4 weeks of the program was strongly associated with weight loss (pr = 0.44, P < 0.001) during the remainder of the intervention. Psychosocial variables were unrelated to attrition or treatment outcome. Discussion: These findings highlight the potential importance of attending to parental BMI in efforts to retain adolescent participants in treatment, as well as the need to develop weight control interventions that are more effective for ethnic minority youth.     

Neighborhood safety, collective efficacy, and obesity in women with young children

Objective : To test the hypothesis that mothers of young children would have a higher prevalence of obesity if they lived in neighborhoods that they perceived as unsafe or as having a low level of collective efficacy. Research Methods and Procedures : Using data from the Fragile Families and Child Wellbeing Study, a cross‐sectional analysis was conducted of 2445 women living in 20 large (population ≥ 200, 000) U.S. cities. BMI was measured on 72% and self‐reported on 28%. Perception of neighborhood safety was assessed with the Neighborhood Environment for Children Rating Scales. The collective efficacy measure was adapted from the Project on Human Development in Chicago Neighborhoods. Results : Thirty percent of the women were married, 38% lived below the U.S. poverty threshold, and 66% reported no education beyond high school. Approximately one‐half of the women were non‐Hispanic black, and one‐fourth were Hispanic (any race). After adjustment for sociodemographic factors (household income, education, race/ethnicity, age, and marital status), smoking, depression, and television time, the prevalence of obesity (BMI ≥ 30 kg/m²) increased across tertiles of neighborhood safety from safest to least safe (37% vs. 41% vs. 46%, p = 0.004) but did not differ across tertiles of collective efficacy from highest to lowest (41% vs. 40% vs. 42%, p = 0.67). Discussion : In a national sample of women with young children, obesity was more prevalent among those who perceived their neighborhoods to be unsafe.     

The Influence of Physical Activity,Socioeconomic Status,and Ethnicity on the Weight Status of Adolescents

Objective: This study examined the effects of physical activity, television viewing, video game play, socioeconomic status (SES), and ethnicity on body mass index (BMI). Research Methods and Procedures: The sample was 2389 adolescents, 10 to 16 years of age (12.7 ± 1.0 years); 1240 (52%) females and 1149 (48%) males; 77% white and 23% African American; from rural (77%) and urban (23%) settings. BMI and skinfolds were directly assessed. All other data were obtained from questionnaires. Results: Watching television on non‐school days was related to being overweight (p < 0.005). However, when BMI analyses were adjusted for ethnicity and SES, there were no significant effects of television viewing on BMI (p > 0.061). Increased hours of video game play enhanced the risk of being overweight for both genders when analyses were adjusted for ethnicity and SES (p < 0.019). In males, participation in as little as one high‐intensity physical activity 3 to 5 days a week decreased the ethnic‐ and SES‐adjusted relative risk of being overweight (RR = 0.646; CI: 0.427 to 0.977). For females, the ethnic‐ and SES‐adjusted relative risk for being overweight was not significantly altered by physical activity. The logistic analyses further indicated the influence of low SES and African American ethnicity overshadowed any direct effect of television or videos. Discussion: Because weight status of male adolescents appears to be more related to exercise habits than to television or video game habits, increased participation in high‐intensity exercise appears to be important. For females, neither videos nor exercise habits appear to be related to risk of being overweight. However, ethnicity and SES may be important factors that can influence body weight status, while television viewing may be of some importance. Thus, programs to reduce obesity in female adolescent should focus their efforts in lower SES communities.     

Genetic Epidemiology of BMI and Body Mass Change From Adolescence to Young Adulthood

The complex interplay between genes and environment affecting body mass gain over lifecycle periods of risk is not well understood. We use longitudinal sibling cohort data to examine the role of shared household environment, additive genetic, and shared genetic effects on BMI and BMI change. In the National Longitudinal Study of Adolescent Health, siblings and twin pairs sharing households for ≥10 years as adolescents (N = 5,524; mean = 16.5 ± 1.7 years) were followed into young adulthood (N = 4,368; mean = 22.4 ± 1.8 years). Using a variance component approach, we quantified genetic and household effects on BMI in siblings and nonsiblings sharing household environments over time. Adjusting for race, age, sex, and age‐by‐sex interaction, we detected a heritability of 0.43 ± 0.05 for BMI change. Significant household effects were noted during the young adulthood period only (0.11 ± 0.06). We find evidence for shared genetic effects between BMI and BMI change during adolescence (genetic correlation (ρ_G) = 0.61 ± 0.03) and young adulthood (ρ_G = 0.23 ± 0.06). Our findings support a complex etiology of BMI and BMI change.     

Body mass index gain, fast food, and physical activity: effects of shared environments over time

Objective : The magnitude of environmental vs. genetic effects on BMI, diet, and physical activity (PA) is widely debated. We followed a sibling cohort (where individuals shared households in childhood and adolescence) to young adulthood (when some continued sharing households and others lived apart) to examine the role of discordant environments in adult twins’ divergent trends in BMI and health behaviors and to quantify the variation in BMI and behavior among all siblings that is attributable to environmental and additive genetic effects. Research Methods and Procedures : In the National Longitudinal Study of Adolescent Health, siblings sharing households for ≥10 years as adolescents (mean age = 16.5 ± 1.7 years; N = 5524) were followed into adulthood (mean = 22.4 ± 1.8 years; N = 4368), self‐reporting PA, sedentary behavior, and dietary characteristics. Adult BMI and adolescent z scores were derived from measured height and weight. Results : Compared with those living together, twins living apart exhibited greater discordance in change in BMI, PA, and fast food intake from adolescence to adulthood. Adolescent household environments accounted for 8% to 10% of variation in adolescent fast food intake and sedentary behaviors and 50% of variation in adolescent overweight. Adolescent household effects on PA were substantially greater in young adulthood (accounting for 50% of variation) vs. adolescence. Young adult fast food intake was significantly affected by young adult household environment, accounting for 12% of variation. Discussion : These findings highlight important environmental influences on BMI, PA, and fast food intake during the transition to adulthood. Household and physical environments play an important role in establishing long‐term behavior patterns.     

Media use and obesity in adolescent females

Objective: In the context of growing public health concern with the obesity rates among children and adolescents, much attention has focused on the role of television as a contributor to the problem. Less attention has been devoted to interactive media (internet surfing and video games), despite the fact that these forms of entertainment are fast gaining in popularity among youth. This study investigated the relative associations of TV viewing and interactive media use with body fat and BMI, controlling for both physical activity participation and cardiovascular fitness. Research Methods and Procedures: Female high‐school adolescents (N = 194) were assessed for cardiovascular fitness (cycle ergometer), percent body fat (DXA), and BMI. Time spent in moderate, vigorous, and sedentary activities was assessed with a 3‐day recall. Results: Multivariate regression analysis showed that only interactive media use was associated with percentage body fat and BMI, and the relationship remained strong even after controlling for physical activity participation and cardiovascular fitness. Discussion: It appears that, among this group of adolescent females, the association between interactive media use and obesity is not explained by a reduction in moderate or vigorous activity commensurate with media use.     

The influence of body composition, fat distribution, and sustained weight loss on left ventricular mass and geometry in obesity

Alterations in left ventricular mass and geometry vary along with the degree of obesity, but mechanisms underlying such covariation are not clear. In a case–control study, we examined how body composition and fat distribution relate to left ventricular structure and examine how sustained weight loss affects left ventricular mass and geometry. At the 10‐year follow‐up of the Swedish obese subjects (SOS) study cohort, we identified 44 patients with sustained weight losses after bariatric surgery (surgery group) and 44 matched obese control patients who remained weight stable (obese group). We also recruited 44 matched normal weight subjects (lean group). Dual‐energy X‐ray absorptiometry, computed tomography, and echocardiography were performed to evaluate body composition, fat distribution, and left ventricular structure. BMI was 42.5 kg/m², 31.5 kg/m², and 24.4 kg/m² for the obese, surgery, and lean groups, respectively. Corresponding values for left ventricular mass were 201.4 g, 157.7 g, and 133.9 g (P < 0.001). In multivariate analyses, left ventricular diastolic dimension was predicted by lean body mass (β = 0.03, P < 0.001); left ventricular wall thickness by visceral adipose tissue (β = 0.11, P < 0.001) and systolic blood pressure (β = 0.02, P = 0.019); left ventricular mass by lean body mass (β = 1.23, P < 0.001), total body fat (β = 1.15, P < 0.001) and systolic blood pressure (β = 2.72, P = 0.047); and relative wall thickness by visceral adipose tissue (β = 0.02, P < 0.001). Left ventricular adjustment to body size is dependent on body composition and fat distribution, regardless of blood pressure levels. Obesity is associated with concentric left ventricular remodeling and sustained 10‐year weight loss results in lower cavity size, wall thickness and mass.