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

Sleep Patterns, Eating Behavior and the Risk of Noncommunicable Diseases

Sleep is extremely important for the homeostasis of the organism. In recent years, various studies have been carried out to address factors related to sleep patterns and their influence on food choices, as well as on the onset of chronic noncommunicable diseases. The aim of this article is to provide a scientific literature review on the possible role of sleep patterns on eating behavior and the risk of noncommunicable diseases. A search was performed on Medline (PubMed interface) using several keywords (e.g., "Factors Influencing Sleep" OR "Sleep and Chronic Diseases"). Articles published between 2000 and the present date that relate sleep to cyclic metabolic processes and changes in eating behavior were selected. Changes in sleep patterns are increasingly detected today, and these modifications are mainly caused by work and lifestyle conditions as well as a growing dependence on electronic devices. Sleep deprivation and the resultant short sleep duration lead to an increased appetite via an increase in the hunger hormone (ghrelin) and a decrease in the satiety hormone (leptin). Nowadays, sleep is undervalued, and thus often impaired, with consequences for the performance of various body systems. Sleep deprivation alters physiological homeostasis and influences eating behavior as well as the onset of chronic diseases.

Influence of Using Food Delivery Applications on Adult Saudi Female Dietary Habits and Preferences during COVID-19 Lockdown Restrictions: Attitude Survey

Food delivery applications (FDAs) shined during COVID-19 global lockdown restrictions. Consequently, lifestyle changes imposed a greater use of these applications over this period. These changes may strongly influence the nutritional health of individuals, particularly adult Saudi females. A cross-sectional study was performed to examine the influence of using FDAs during COVID-19 lockdown restrictions on attitude behaviours, including dietary habits and preferences among Saudi adult females. Participants voluntarily submitted their answers to a questionnaire administered via the Google Survey platform. Results illustrated that most Saudi female users of FDAs were aged between 18-24 years with 64.9%, 91.5% being single and 37% ordering food online within one to two days a month. There was a significant association between the influence of using FDAs during COVID-19 lockdown restrictions and age, education, and average days of ordering food online (p ˂ 0.05). Another important factor is that higher education was associated with more frequent use of the FDAs, there were direct relationships between education level and using FDAs, 58% of the participants were educated as undergraduate or postgraduate. Although lifestyle changes increased the use of FDAs during COVID-19 global lockdown restrictions, these changes may negatively affect individuals' dietary habits and preferences, particularly adult Saudi females. These findings can aid in promoting healthy diet management globally and in Saudi Arabia unless the governments lead to significant beneficial changes toward improving food delivery applications.

Association of Household Type and Fast-Food Consumption in Korean Adolescents

Background: Due to changing household types and weakening of family functions, children have fewer opportunities to develop healthy lifestyle patterns from contact with family members compared to the past. In this paper, we evaluate the association between household type and adolescents’ fast-food consumption, focusing on whether they were living with their parents or not, and determine their reasons for not living with their parents. Methods: This cross-sectional study analyzed data from the Korea Youth Risk Behavior web-based survey between 2017 and 2020. The subjects were students in grades 7–12. The outcome variable was a frequency of fast-food intake of ≥5 times per week. The main independent variable was the type of household: (1) living with both parents; (2) living with a single parent (one of father, mother, stepfather, stepmother); (3) not living together, but having parents; and (4) having no parents. Results: Participants without parents were more likely to eat fast food frequently than those living with both parents. Among boys, not having parents and living in a dorm or boarding house or living with other family members or relatives were significantly associated with frequent fast-food intake; among girls, not having parents and living in a dorm or boarding house were significantly associated with frequent fast-food intake. Conclusion: Adolescents having no parents have a higher risk of frequent fast-food intake than those living with both parents. Further studies are needed to address household types in greater detail.

Diet quality comparisons in Hispanic/Latino siblings: Results from the Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth)

The objective of this study was to determine how well Hispanic/Latino siblings' diet quality correlate with each other and whether social and environmental factors explained potential differences. Hispanic/Latino 8-16-year-olds from the cross-sectional Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth) with at least one sibling enrolled in the study were examined (n = 740). Diet quality was assessed with the Healthy Eating Index 2010 (HEI-2010), calculated from two 24-h recalls. Mixed effects models were used with HEI-2010 score as the outcome, and correlations in siblings' diet quality were assessed with intraclass correlation coefficients (ICCs). All models were examined stratified by age and sex. Diet-related social and environmental measures were added as fixed effects in a secondary analysis. Mean (standard deviation) overall HEI-2010 score was 53.8 (13.0). The ICC for siblings' HEI-2010 score was 0.31 (95% CI: 0.25, 0.38). Siblings who were born <3 vs. ≥3 years apart had stronger correlations in overall diet quality (0.47 [95% CI: 0.37, 0.58] vs. 0.21 [95% CI: 0.13, 0.30]), but no differences were observed in overall HEI-2010 score according to sex. Greater peer support for fruit and vegetable intake (β = 1.42 [95% CI: 0.62, 2.21]) and greater away-from-home food consumption (β = -1.24 [95% CI: -2.15, -0.32]) were associated with differences in siblings' diet quality. Overall diet quality scores of Hispanic/Latino siblings in this study were slightly correlated, with stronger correlations among siblings closer in age. Differences in peer support and foods consumed outside the home may explain differences in siblings' diet quality. Future research should investigate additional determinants of differences in siblings' diets.

A Causal Estimate of Long-Term Health Care Spending Attributable to Body Mass Index Among Adults

While high body mass index (BMI) is believed to be a major driver of poor health, there is little evidence about whether it leads to higher health care spending. Understanding the causal contribution of BMI to health care spending is necessary to estimate the returns to investment in weight loss efforts. We exploit genetic variation in BMI across siblings as a natural experiment to estimate the impact of BMI on cumulative third party and out-of-pocket health care spending among adults using the Panel Study of Income Dynamics data from 1999 through 2011. We estimate a two-stage residual inclusion model with a generalized linear model. We find a $611.60 increase in cumulative insurer spending for each one-unit increase in BMI. This amounts to $130.49 in mean annual spending, and is two times higher than the non-causal estimate. We find no difference in out-of-pocket spending by BMI. These findings suggest that having a higher BMI in young/middle adulthood leads to significantly higher insurer health expenditures over the life course, which can help to inform public and private insurer policies on BMI reduction and control.

Bi-Directional Associations Between Real-Time Affect and Physical Activity in Weight-Discordant Siblings

Pediatric obesity confers increased risk for a host of negative psychological and physical health consequences and is reliably linked to low levels of physical activity. Affective antecedents and consequences of physical activity are thought to be important for the development and maintenance of such behavior, though research examining these associations in youth across the weight spectrum remains limited.

OBJECTIVE

This study examined bi-directional associations between affect and physical activity (i.e., moderate-to-vigorous physical activity [MVPA] and total activity counts), and the extent to which weight (body mass index z-score [z-BMI]) moderated these associations.

METHODS

Participants were drawn from a prior study of siblings (N = 77; mean age = 15.4 ± 1.4 years) discordant for weight status (39 nonoverweight siblings, 38 siblings with overweight/obesity) who completed ecological momentary assessment (EMA) with accelerometer-assessed physical activity.

RESULTS

Generalized linear mixed models indicated z-BMI moderated trait-level and momentary associations. When adolescents with higher z-BMI reported momentary negative affect, they evidenced less MVPA within the next hour. Across the sample, greater overall activity was associated with lower negative affect. However, at the momentary level, when adolescents with higher (but not lower) z-BMI evidenced greater activity, they reported decreases in negative affect.

CONCLUSIONS

Findings indicate affective experiences surrounding physical activity differ according to z-BMI. Specifically, momentary negative affect may impede momentary MVPA among youth with higher z-BMI. Further research is warranted to elucidate factors influencing these momentary associations and the extent to which these momentary associations prospectively predict weight change.

Evidence for shared genetics between physical activity, sedentary behaviour and adiposity-related traits

Observational, cross-sectional and longitudinal studies showed that physical activity and sedentary behaviour are associated with adiposity-related traits, apparently in a bidirectional manner. Physical activity is also suggested to suppress the genetic risk of adiposity. Since phenotypic associations with genetic variants are not subject to reverse causation or confounding, they may be used as tools to shed light on cause and effect in this complex interdependency. We review the evidence for shared genetics of physical activity and adiposity-related traits and for gene-by-physical activity interactions on adiposity-related traits in human studies. We outline limitations, challenges and opportunities in studying and understanding of these relationships. In summary, physical activity and sedentary behaviour are genetically correlated with body mass index and fat percentage but may not be correlated with lean body mass. Mendelian randomisation analyses show that physical activity and sedentary behaviour have bidirectional relationships with adiposity. Several studies suggest that physical activity suppresses genetic risk of adiposity. No studies have yet tested whether adiposity enhances genetic predisposition to sedentariness. The complexity of the comprehensive causal model makes the assessment of the single or combined components challenging. Substantial progress in this field may need long-term intervention studies.

Network organization during probabilistic learning via taste outcomes

Reinforcement learning guides food decisions, yet how the brain learns from taste in humans is not fully understood. Existing research examines reinforcement learning from taste using passive condition paradigms, but response-dependent instrumental conditioning better reflects natural eating behavior. Here, we examined brain response during a taste-motivated reinforcement learning task and how measures of task-based network structure were related to behavioral outcomes. During a functional MRI scan, 85 participants completed a probabilistic selection task with feedback via sweet taste or bitter taste. Whole brain response and functional network topology measures, including identification of communities and community segregation, were examined during choice, sweet taste, and bitter taste conditions. Relative to the bitter taste, sweet taste was associated with increased whole brain response in the hippocampus, oral somatosensory cortex, and orbitofrontal cortex. Sweet taste was also related to differential community assignment of the ventromedial prefrontal cortex and ventrolateral prefrontal cortex compared to bitter taste. During choice, increasing segregation of a community containing the amygdala, hippocampus, and right fusiform gyrus was associated with increased sensitivity to punishment on the task's posttest. Further, normal BMI was associated with differential community structure compared to overweight and obese BMI, where high BMI reflected increased connectivity of visual regions. Together, results demonstrate that network topology of learning and memory regions during choice is related to avoiding a bitter taste, and that BMI is associated with increased connectivity of area involved in processing external stimuli. Network organization and topology provide unique insight into individual differences in brain response to instrumental conditioning via taste reinforcers.

Heritability of objectively assessed and self-reported sedentary behavior

Understanding the sources of the large individual differences in sedentary behavior is of great importance as this behavior is associated with pre-mature mortality and non-communicable diseases. Here, we report on the contribution of genetic and environmental factors to the variation in objectively assessed (accelerometer) sedentary behavior and self-reported sitting and their shared genetic basis. In addition, the overlap of the genetic risk factors influencing sedentary time and moderate-to-vigorous physical activity (MVPA) was estimated. A sample of 800 individuals (twins and their siblings) was equipped with an Actigraph accelerometer for 7 days and reported on their sitting time and time spent on MVPA on those days using the IPAQ-SF. Genetic factors explained 56% (CI: 44%, 65%) of the individual differences in objective sedentary behavior (Actigraph) and 26% (CI: 0%, 51%) of the individual differences in self-reported sedentary behavior (IPAQ-SF). A modest correlation (0.33) was found between these measures, which was for 45% accounted for by genetic influences. The genetic correlation was 0.49 reflecting a partly overlapping set of genes that influenced both measurements. A modest correlation (-0.27) between Actigraph-derived sedentary time and MVPA was found, which was 13% accounted for by genetic effects. The genetic correlation was -0.31, indicating that there are overlapping genetic variants that increase sedentary time and decrease MVPA or vice versa. To conclude, more than half of the individual differences in objective sedentary time could be attributed to genetic differences, while for self-reported sitting this was much lower. In addition, using objective measurements, this study confirms that sedentary time is not simply the inverse of MVPA. Future studies are needed to understand the pathways translating genomic variation into variation in these behaviors and how this knowledge might feed into the development of health promotion interventions.

Does a rise in BMI cause an increased risk of diabetes?: Evidence from India

BACKGROUND

Overnutrition increases the risk of diabetes. Evidence on the causal impact of overnutrition on diabetes is scarce for India. Considering a representative sample from India, this study examines the causal effect of a rise in the Body Mass Index (BMI) of an individual on the likelihood of being diabetic while addressing the issue of unobserved endogeneity between overnutrition and diabetes.

METHODS

The study considers individual level data from Demographic and Health Surveys (DHS) of India, namely, National Family Health Survey (NFHS) for the year 2015-16. The NFHS is a large-scale, multi-round survey conducted in a representative sample of households throughout India. The survey covers females having age 15-49 years and males having age 15-54 years. The instrument variable approach is used to address the potential endogeneity in the relationship between BMI and diabetes. We instrument BMI of an individual by BMI of a non-biologically related household member. Ordered Probit, Probit and IV-Probit models are estimated using two alternative definitions for measuring diabetes-self-reported diabetes status and blood glucose levels (ordinal measure).

RESULTS

The coefficients obtained from the Ordered Probit and Probit models are much smaller than those estimated by an IV-Probit model. The latter estimates the causal impact of a rise in BMI on diabetes by taking into account the effect of the unobserved genetic and other related factors. The likelihood of being diabetic is twice or more among the overweight and obese individuals as compared to non-overweight individuals in all the specifications. With a unit increase in BMI the probability of being diabetic increases by about 1.5% among overweight and obese individuals and by 0.5% among the non-overweight individuals in the IV-Probit model. Similar results from the Ordered Probit model show that on average, the overweight and obese individuals experience about 0.2% increase in the probability of being diabetic and about 0.4% increase in the probability of being prediabetic.

CONCLUSION

Our study demonstrates that the likelihood of being both prediabetic and diabetic is higher among the overweight and obese individuals as compared to the non-overweight individuals. We also find that the level of risk of being prediabetic or diabetic differs across gender, wealth quintiles and regions and the effects are more severe among population in the urban areas, belonging to the richest wealth quintile and men. Our findings have significant implications for the policy formulation as diabetes has a substantial health and economic burden associated with it. Future studies may investigate the effect of abdominal obesity on diabetes.

Association of parental body mass index (BMI) with child's health behaviors and child's BMI depend on child's age

Background

Parent’s and child’s body mass index (BMI) are strongly associated, but their relationship varies by child’s sex and age. Parental BMI reflects, among other factors, parents’ behaviors and home environment, which influence their child’s behaviors and weight. This study examined the indirect effect of parent’s BMI on child’s BMI via child health behaviors, conditional on child’s sex and age.

Methods

Data from 2039 children and 1737 parents from eight cities of the U.S. involved in the Childhood Obesity Research Demonstration project tested the association between parental BMI and child’s percentage of 95th BMI percentile (%BMIp95). A generalized structural equation modeling approach to path analysis was used to estimate and test simultaneously the associations among parental BMI and child’s health behaviors and BMI across three age groups (preschool 2-4 yr., elementary 5-10 yr., and middle school 11-12 yr). Child’s health behaviors were examined as mediators.

Results

Parental BMI was related to %BMIp95 across all age groups, and was strongest in 11-12 yr. children. Parental BMI was positively associated with boys’ fruit and vegetable (FV) intake and girls’ sugar-sweetened beverage (SSB) intake. Compared to 2-4 yr., older children had less FVs and physical activity, more screen time and SSB, and higher %BMIp95. Mediation effects were not significant.

Conclusions

Parental BMI was associated with child’s %BMIp95 and some child behaviors, and this association was stronger in older children; older children also exhibited less healthy behaviors. Age- and sex-specific interventions that focus on age-related decreases in healthy behaviors and parental strategies for promoting healthy behaviors among at-risk children are needed to address this epidemic of childhood obesity.

Profile Resemblance in Health-Related Markers: The Portuguese Sibling Study on Growth, Fitness, Lifestyle, and Health

The co-occurrence of health-related markers and their associations with individual, family, and environmental characteristics have not yet been widely explored in siblings. We aimed to identify multivariate profiles of health-related markers, analyze their associations with biological, sociodemographic, and built environment characteristics, and estimate sibling resemblance in these profiles. The sample includes 736 biological siblings aged 9–20 years. Body fat was measured with a portable bioelectrical impedance scale; biological maturation was assessed with the maturity offset; handgrip strength, standing long jump, one-mile run, and shuttle run were used to mark physical fitness. Health behaviors, sociodemographic, and built environmental characteristics were recorded by questionnaire. Latent profile analysis and multilevel logistic regression models were used; sibling resemblance was estimated with the intraclass correlation (ρ). Two multivariate profiles emerged: “P1 = fit, lower fat and poorer diet” (86.7%) and “P2 = higher fat and lower fit, but better diet” (13.3%). Siblings whose fathers were less qualified in their occupation were more likely to belong to P2 (OR = 1.24, p = 0.04); those whose fathers with Grade 12 and university level education were more likely to fit in P2 compared to peers living with fathers having an educational level below Grade 12 (OR = 3.18, p = 0.03, and OR = 6.40, p = 0.02, Grade 12 and university level, respectively). A moderate sibling profile resemblance was found (0.46 ≤ ρ ≤ 0.55). In conclusion, youth health-related markers present substantial differences linked with their body composition, physical fitness and unhealthy diet. Furthermore, only father socio-demographic characteristics were associated with profile membership. Sibling´s profile resemblance mirrors the effects of genetics and shared characteristics.

Dietary Habits and Eating Practices and Their Association with Overweight and Obesity in Rural and Urban Black South African Adolescents

The aim of this study was to investigate differences/similarities in dietary habits and eating practices between younger and older, rural and urban South African adolescents in specific environments (home, community and school) and their associations with overweight and obesity. Dietary habits, eating practices, and anthropometric measurements were performed on rural (n = 392, mean age = 13 years) and urban (n = 3098, mean age = 14 years) adolescents. Logistic regression analysis was used to examine the associations between dietary habits and eating practices, with overweight and obesity risk. Differences in dietary habits and eating practices by gender and by site within the three environments were identified. After adjusting for gender, site, dietary habits, and eating practices within the home, community and school environment, eating the main meal with family some days (OR = 1.78, 95% CI = 1.114-2.835; p ≤ 0.02), eating the main meal with family almost every day (OR = 1.61, 95% CI = 1.106-2.343; p ≤ 0.01), and irregular frequency of consuming breakfast on weekdays (OR = 1.38, 95% CI = 1.007-1.896; p ≤ 0.05) were all associated with increased risk of overweight and obesity. For "Year 15" adolescents, irregular frequency of consuming breakfast on weekends within the home environment (OR = 1.53, 95% CI = 1.099-2.129, p ≤ 0.01), was associated with increased risk of overweight and obesity. For both early- and mid-adolescents, being male (OR = 0.401, 95% CI = 0.299-0.537; p ≤ 0.00; OR = 0.29, 95% CI = 0.218-0.397; p ≤ 0.00) was associated with reduced risk of overweight and obesity, while residing in a rural setting (OR = 0.55, 95% CI = 0.324-0.924; p ≤ 0.02) was associated with reduced risk of overweight and obesity only among early-adolescents. Only dietary habits and eating practices within the home environment were associated with increased risk of overweight and obesity.

Change in diet in the period from adolescence to early adulthood: a systematic scoping review of longitudinal studies

BACKGROUND

Late adolescence to early adulthood is a period of lifestyle change and personal development which may influence dietary behaviour. Understanding dietary trajectories across this age range may help in targeting interventions appropriately. This scoping review aimed to assess how longitudinal change in diet is conceptualised and measured between the ages of 13 to 30.

METHODS

We searched Medline, SCOPUS, Embase, PsycInfo (EBSCO), ASSIA, Sportdiscus, and Web of Science Core Collection (January 2016) using search terms combining diet outcomes, longitudinal methods and indicators of adolescent or young adult age. Titles and abstracts were screened and data extracted following published guidelines for scoping reviews. Data were analysed to summarize key data on each study and map availability of longitudinal data on macronutrients and food groups by age of study participants.

RESULTS

We identified 98 papers reporting on 40 studies. Longitudinal dietary data were available on intake of energy, key macronutrients and several food groups, but this data had significant gaps and limitations. Most studies provided only two or three waves of data within the age range of interest and few studies reported data collected beyond the early twenties. A range of dietary assessment methods were used, with greater use of less comprehensive dietary assessment methods among studies reporting food group intakes.

CONCLUSION

Despite limited availability of longitudinal data to aid understanding of dietary trajectories across this age range, this scoping review identified areas with scope for further evidence synthesis. We identified a paucity of longitudinal data continuing into the mid and late twenties, variability in (quality of) dietary assessment methods, and a large variety of macronutrients and food groups studied. Advances in dietary assessment methodologies as well as increased use of social media may facilitate new data collection to further understanding of changing diet across this life stage.

Incremental impact of body mass status with modifiable unhealthy lifestyle behaviors on pharmaceutical expenditure

BACKGROUND

Overweight/obesity is a growing health risk in Korea. The impact of overweight/obesity on pharmaceutical expenditure can be larger if individuals have multiple risk factors and multiple comorbidities. The current study estimated the combined effects of overweight/obesity and other unhealthy behaviors on pharmaceutical expenditure.

METHODS

An instrumental variable quantile regression model was estimated using Korea Health Panel Study data. The current study extracted data from 3 waves (2009, 2010, and 2011).

RESULTS

The final sample included 7148 person-year observations for adults aged 20 years or older. Overweight/obese individuals had higher pharmaceutical expenditure than their non-obese counterparts only at the upper quantiles of the conditional distribution of pharmaceutical expenditure (by 119% at the 90th quantile and 115% at the 95th). The current study found a stronger association at the upper quantiles among men (152%, 144%, and 150% at the 75th, 90th, and 95th quantiles, respectively) than among women (152%, 150%, and 148% at the 75th, 90th, and 95th quantiles, respectively). The association at the upper quantiles was stronger when combined with moderate to heavy drinking and no regular physical check-up, particularly among males.

CONCLUSION

The current study confirms that the association of overweight/obesity with modifiable unhealthy behaviors on pharmaceutical expenditure is larger than with overweight/obesity alone. Assessing the effect of overweight/obesity with lifestyle risk factors can help target groups for public health intervention programs.

Pilot Study of a Computer-Based Parental Questionnaire and Visual Profile of Obesity Risk in Healthy Preschoolers

PURPOSE

This group field-tested a computer-based, parental questionnaire entitled the Childhood Obesity Risk Questionnaire 2-5 (CORQ 2-5) designed to assess obesity risk in healthy preschoolers. COR 2-5 generates a profile of seven obesity risk factors.

RESULTS

Field studies provided good internal reliability data and evidence of discriminant validity for the CORQ 2-5. Pediatric nurse clinicians found the CORQ 2-5 profile to be clinically relevant.

CONCLUSION

The CORQ 2-5 is a promising measure of obesity risk in preschoolers who attend community-based health centers for their wellchild visits and who are not yet obese. CORQ 2-5 is intended to guide provider-parental obesity risk discussions.

Individual- and neighborhood-level education influences the effect of obesity on prostate cancer treatment failure after prostatectomy

Purpose

The relationship between obesity and prostate cancer (CaP) treatment failure is complex and may vary by patient- and neighborhood-level educational attainment. We evaluated whether patient- and neighborhood-level education is associated with the effect of obesity on biochemical recurrence.

Methods

Seven hundred and forty-six CaP cases were classified into four groups: Concordant Low–Low: less educated cases (<4 years college) living in a less educated neighborhood (below-median proportion of college-educated residents; n = 164); Concordant High–High: highly educated cases (≥4 years college) living in a highly educated neighborhood (above-median proportion of college-educated residents; n = 326); Discordant Low–High: less educated cases living in a highly educated neighborhood (n = 69); and Discordant High–Low: highly educated cases living in a less educated neighborhood (n = 187). Cox regression models were used to examine associations between obesity and biochemical (PSA) failure after prostatectomy stratified by the concordant/discordant groups.

Results

The association of obesity with biochemical failure varied significantly by educational concordance/discordance (p = 0.007). Obesity was associated with risk of biochemical failure for less educated cases residing in less educated neighborhoods (HR 3.72, 95 % CI 1.30–10.65). The relationship was not significant for other concordant/discordant groups.

Conclusions

Obesity effects on CaP outcomes vary by multilevel educational discordance/concordance. Strategies to decrease prostate cancer risk of progression may focus on reduction in obesity, particularly for less educated cases residing in less educated neighborhoods.

Associations Between Fast-Food Consumption and Body Mass Index: A Cross-Sectional Study in Adult Twins

Obesity is a substantial health problem in the United States, and is associated with many chronic diseases. Previous studies have linked poor dietary habits to obesity. This cross-sectional study aimed to identify the association between body mass index (BMI) and fast-food consumption among 669 same-sex adult twin pairs residing in the Puget Sound region around Seattle, Washington. We calculated twin-pair correlations for BMI and fast-food consumption. We next regressed BMI on fast-food consumption using generalized estimating equations (GEE), and finally estimated the within-pair difference in BMI associated with a difference in fast-food consumption, which controls for all potential genetic and environment characteristics shared between twins within a pair. Twin-pair correlations for fast-food consumption were similar for identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins, but were substantially higher in MZ than DZ twins for BMI. In the unadjusted GEE model, greater fast-food consumption was associated with larger BMI. For twin pairs overall, and for MZ twins, there was no association between within-pair differences in fast-food consumption and BMI in any model. In contrast, there was a significant association between within-pair differences in fast-food consumption and BMI among DZ twins, suggesting that genetic factors play a role in the observed association. Thus, although variance in fast-food consumption itself is largely driven by environmental factors, the overall association between this specific eating behavior and BMI is largely due to genetic factors.

All in the family: correlations between parents' and adolescent siblings' weight and weight-related behaviors

OBJECTIVE

To examine whether and how parents' and adolescent siblings' weight and weight-related behaviors are correlated. Results will inform which family members may be important to include in adolescent obesity prevention interventions.

METHODS

Data from two linked population-based studies, EAT 2010 and F-EAT, were used for cross-sectional analyses. Parents (n = 58; 91% females; mean age = 41.7 years) and adolescent siblings (sibling #1 n = 58, 50% girls, mean age = 14.3 years; sibling #2 n = 58, 64% girls, mean age = 14.8 years) were socioeconomically and racially/ethnically diverse.

RESULTS

Some weight-related behaviors between adolescent siblings were significantly positively correlated (i.e., fast food consumption, breakfast frequency, sedentary patterns, p < 0.05). There were no significant correlations between parents' weight and weight-related behaviors and adolescent siblings' same behaviors. Some of the significant correlations found between adolescent siblings' weight-related behaviors were statistically different from correlations between parents' and adolescent siblings' weight-related behaviors.

CONCLUSIONS

Although not consistently, adolescent siblings' weight-related behaviors were significantly correlated as compared with parents' and adolescent siblings' weight-related behaviors. It may be important to consider including siblings in adolescent obesity prevention interventions or in recommendations healthcare providers give to adolescents regarding their weight and weight-related behaviors.

Trends of fast food consumption among adolescent and young adult Saudi girls living in Riyadh

Background : Saudi Arabia has passed through lifestyle changes toward unhealthy dietary patterns such as high fast food consumption. Adolescents and young adults, particularly girls, are the main groups exposed to and affected by these adverse eating behaviors. Objective : The aim of this study was to examine the trends of fast food consumption among adolescent and young adult Saudi girls living in Riyadh, and to compare between them. Design : In a cross-sectional survey, 127 adolescent Saudi girls (13-18 years) and 69 young adult Saudi girls (19-29 years) were randomly recruited to participate in this study. Weight, height, waist circumference, and hip circumference were measured using standardized methods. Twenty-four-hour diet recall and a face-to-face interview food questionnaire were performed. Results : Most of the participants had adequate intake of protein, riboflavin, iron, and sodium, but exhibited low intake for several other nutrients. Among study participants, 95.4% consume restaurants' fast food and 79.1% eat fast food at least once weekly. Burgers and carbonated soft drinks were the main kinds of fast food meals and beverages usually eaten by girls. Adolescent girls who usually ate large portion sizes of fast food had significantly higher mean waist circumference and hip circumference. Participants eat fast food primarily for enjoying the delicious taste, followed by convenience. Restaurants' hygiene and safety standards were the main concern regarding fast food for 62.2% of girls. Finally, international restaurants were preferable by participants to buy fast food compared with local restaurants (70.9% vs. 29.1%). Conclusion : Our findings provide evidence on the high prevalence of fast food consumption among Saudi girls, suggesting an urgent need for community-based nutrition interventions that consider the trends of fast food consumption and targeted eating behaviors of adolescent and young adult girls.

SeqSIMLA2: simulating correlated quantitative traits accounting for shared environmental effects in user-specified pedigree structure

Simulation tools that simulate sequence data in unrelated cases and controls or in families with quantitative traits or disease status are important for genetic studies. The simulation tools can be used to evaluate the statistical power for detecting the causal variants when planning a genetic epidemiology study, or to evaluate the statistical properties for new methods. We previously developed SeqSIMLA version 1 (SeqSIMLA1), which simulates family or case-control data with a disease or quantitative trait model. SeqSIMLA1, and several other tools that simulate quantitative traits, do not specifically model the shared environmental effects among relatives on a trait. However, shared environmental effects are commonly observed for some traits in families, such as body mass index. SeqSIMLA1 simulates a fixed three-generation family structure. However, it would be ideal to simulate prespecified pedigree structures for studies involving large pedigrees. Thus, we extended SeqSIMLA1 to create SeqSIMLA2, which can simulate correlated traits and considers the shared environmental effects. SeqSIMLA2 can also simulate prespecified large pedigree structures. There are no restrictions on the number of individuals that can be simulated in a pedigree. We used a blood pressure example to demonstrate that SeqSIMLA2 can simulate realistic correlation structures between the systolic and diastolic blood pressure among relatives. We also showed that SeqSIMLA2 can simulate large pedigrees with large chromosomal regions in a reasonable time frame.

Is the gene-environment interaction paradigm relevant to genome-wide studies? The case of education and body mass index

This study uses data from the Framingham Heart Study to examine the relevance of the gene-environment interaction paradigm for genome-wide association studies (GWAS). We use completed college education as our environmental measure and estimate the interactive effect of genotype and education on body mass index (BMI) using 260,402 single-nucleotide polymorphisms (SNPs). Our results highlight the sensitivity of parameter estimates obtained from GWAS models and the difficulty of framing genome-wide results using the existing gene-environment interaction typology. We argue that SNP-environment interactions across the human genome are not likely to provide consistent evidence regarding genetic influences on health that differ by environment. Nevertheless, genome-wide data contain rich information about individual respondents, and we demonstrate the utility of this type of data. We highlight the fact that GWAS is just one use of genome-wide data, and we encourage demographers to develop methods that incorporate this vast amount of information from respondents into their analyses.

A study of sedentary behaviour in the older Finnish twin cohort: a cross sectional analysis

The aim of the study was to investigate the effects of age, sex, and body mass index (BMI) on total sitting time among the Finnish twin cohort. Also, heritability and environmental factors were analysed. The final sample included 6713 twin individuals 53-67 years of age (46% men). Among them there were 1940 complete twin pairs (732 monozygotic [MZ] and 1208 dizygotic [DZ] twin pairs). Sedentary behaviour was queried with a self-reported questionnaire with multiple-choice questions about sitting time at different domains. The mean total sitting time per day was 6 hours 41 minutes (standard deviation: 2 hours 41 minutes). The total sitting time was less in women than in men (P = 0.002). Older age was associated with less total sitting time (P < 0.001). Those with higher body mass index had higher total sitting time in age and sex adjusted analysis (P < 0.001). MZ pairs were more similar for sitting time than DZ pairs, with initial estimates of heritability for the total sitting time of 35%.The influence of shared environmental factors was negligible (1%), while most (64%) of the variation could be ascribed to unique environmental factors, the latter including measurement error.

Association of infant feeding and dietary intake on obesity prevalence in low-income toddlers

OBJECTIVE

This cross-sectional study assesses the independent and combined effects of breastfeeding (BF) and dietary intake, specifically sugar-sweetened beverages (SSB), on obesity prevalence in low-income, primarily Hispanic toddlers.

METHODS

The following data were collected in 2011 via phone surveys with caregivers of 2295 low-income children (2-4 years) from Los Angeles County Women, Infants, and Children (WIC) programs: infant feeding, dietary intake, gestational diabetes status, birth weight, gestational age, and mother's BMI. WIC staff measured children's height and weight. Chi-square tests and binary logistic regressions assessed the independent and combined effects of BF and dietary intake on obesity prevalence.

RESULTS

Compared to no BF, BF ≥ 12 mos was associated with a 47% reduction in obesity prevalence (AOR = 0.53, 95% CI 0.4-0.8, P = 0.004). Compared to 2 + SSB/d, no SSB/d intake was associated with a 28% reduction in obesity prevalence (AOR = 0.72, 95% CI 0.5-1.0, P = 0.03). High intake of soda, diet soda, and fruit drinks were linked to increases in obesity prevalence. There was no effect of 100% juice, milk (plain or flavored) fruit, vegetable, fast food, or sweetened grain intake on obesity prevalence.

CONCLUSIONS

These findings support encouragement of BF ≥ 12 mos and no SSB intake to prevent obesity in low-income, primarily Hispanic, toddlers.

Genotype by energy expenditure interaction and body composition traits: The Portuguese Healthy Family Study

Background and Aims. Energy expenditure has been negatively correlated with fat accumulation. However, this association is highly variable. In the present study we applied a genotype by environment interaction method to examine the presence of Genotype x by Total Daily Energy Expenditure and Genotype x by Daily Energy Expenditure interactions in the expression of different body composition traits. Methods and Results. A total of 958 subjects from 294 families of The Portuguese Healthy Family Study were included in the analysis. TDEE and DEE were assessed using a physical activity recall. Body fat percentages were measured with a bioelectrical impedance scale. GxTDEE and GxDEE examinations were performed using SOLAR 4.0 software. All BC traits were significantly heritable, with heritabilities ranging from 21% to 34%. The GxTDEE and GxDEE interaction models fitted the data better than the polygenic model for all traits. For all traits, a significant GxTDEE and GxDEE interaction was due to variance heterogeneity among distinct levels of TDEE and DEE. For WC, GxTDEE was also significant due to the genetic correlation function. Conclusions. TDEE and DEE are environmental constraints associated with the expression of individuals' BC genotypes, leading to variability in the phenotypic expression of BC traits.

A prospective multifactorial intervention on subpopulations of predominately Hispanic children at high risk for obesity

OBJECTIVE

Study the effects of multiple exercise and nutritional educational interventions on adverse body mass index (BMI) gain of BMI sub-groups of predominately Hispanic six through eight year-old children at high risk for obesity.

METHODS

BMI and demographic data were recorded at baseline and six months later in 749 first and second grade public school children at four elementary schools. Two schools (intervention group) received 150 min of extra physical education classes, weekly cooking classes, a structured nutritional curriculum, and parental counseling. BMI changes were calculated for each student and compared by BMI percentile subgroups using the two tailed T-test.

RESULTS

No statistical BMI differences occurred between intervention and control group children below the 25th percentile. Significance differences in BMI gain were noted from the 25th to the 50th percentile (P = 0.027), 50th-75th percentile (P = 0.045), and 75th-95th percentile (P = 0.00007), but not for the 95th-98th percentile (P = 0.288), 98th and above (P = 0.223), or both obese groups combined (P = 0.085).

CONCLUSIONS

Nutritional education and exercise can prevent but not treat obesity in predominately Hispanic first and second grade children. BMI subgroups should be studied to avoid masking differing outcomes of obese and nonobese children.

Leisure time activities in adolescence in the presence of susceptibility genes for obesity: risk or resilience against overweight in adulthood? The HUNT study

BACKGROUND

Environment, health behavior, and genetic background are important in the development of obesity. Adolescents spend substantial part of daily leisure time on cultural and social activities, but knowledge about the effects of participation in such activities on weight is limited.

METHODS

A number of 1450 adolescents from the Norwegian HUNT study (1995-97) were followed-up in 2006-08 as young adults. Phenotypic data on lifestyle and anthropometric measures were assessed using questionnaires and standardized clinical examinations. Genotypic information on 12 established obesity-susceptibility loci were available for analyses. Generalized estimating equations were used to examine the associations between cultural and social activities in adolescence and adiposity measures in young adulthood. In addition, interaction effects of a genetic predisposition score by leisure time activities were tested.

RESULTS

In girls, participation in cultural activities was negatively associated with waist circumference (WC) (B = -0.04, 95%CI: -0.08 to -0.00) and with waist-hip ratio (WHR) (B = -0.058, 95%CI: -0.11 to -0.01). However, participation in social activities was positively associated with WC (B = 0.040, CI: 0.00 to 0.08) in girls and with BMI (B = 0.027, CI: 0.00 to 0.05) in boys. The effect of the obesity-susceptibility genetic variants on anthropometric measures was lower in adolescents with high participation in cultural activities compared to adolescents with low participation.

CONCLUSION

This study suggests that the effects of cultural activities on body fat are different from the effects of participation in social activities. The protective influence of cultural activities in female adolescents against overweight in adulthood and their moderating effect on obesity-susceptibility genes suggest that even cultural activities may be useful in public health strategies against obesity.

The influence of local food environments on adolescents' food purchasing behaviors

This study examined the relationship between the neighborhood food environment and the food purchasing behaviors among adolescents. Grade 7 and 8 students (n = 810) at 21 elementary schools in London, Ontario, Canada completed a questionnaire assessing their food purchasing behaviors. Parents of participants also completed a brief questionnaire providing residential address and demographic information. A Geographic Information System (GIS) was used to assess students' home and school neighborhood food environment and land use characteristics. Logistic regression analysis was conducted to assess the influence of the home neighborhood food environment on students' food purchasing behaviors, while two-level Hierarchical Non-Linear Regression Models were used to examine the effects of school neighborhood food environment factors on students' food purchasing behaviors. The study showed that approximately 65% of participants reported self-purchasing foods from fast-food outlets or convenience stores. Close proximity (i.e., less than 1 km) to the nearest fast-food outlet or convenience store in the home neighborhood increased the likelihood of food purchasing from these food establishments at least once per week by adolescents (p < 0.05). High fast-food outlet density in both home and school neighborhoods was associated with increased fast-food purchasing by adolescents (i.e., at least once per week; p < 0.05). In conclusion, macro-level regulations and policies are required to amend the health-detracting neighborhood food environment surrounding children and youth's home and school.

Heritability of body mass index in pre-adolescence, young adulthood and late adulthood

Increased body mass index (BMI) is a worldwide health issue. Individual differences in the susceptibility to increased BMI could be related to genes or environment. We performed a systematic review of genetic studies on BMI in pre-adolescence, young adulthood and late adulthood. We searched PubMed and EMBASE with heritability, body mass index, BMI, weight, height, anthropometry and twins as search terms. Studies reporting intra-pair correlations of healthy twin pairs that were raised together were included. This resulted in the inclusion of 8,179 monozygotic (MZ) and 9,977 dizygotic (DZ) twin pairs from twelve published studies in addition to individual participant data for 629 MZ and 594 DZ pairs from four twin registries. Structural equation modelling with intra-pair twin correlations showed that the heritability of BMI remained high over all age categories ranging from 61% (95% CI 54-64%) to 80% (95% CI 76-81%) for male and female subjects combined, while unique environmental influences increased from 14% (95% CI 13-15%) to 40% (95% CI 37-43%) with increasing age. Heritability of BMI remains consistently high over different age categories. Environmental changes over time do not seem to have as big a relative impact on an individual's weight as previously reported, suggesting a mainly genetic influence on variation in BMI over the years.

The medical care costs of obesity: an instrumental variables approach

This paper is the first to use the method of instrumental variables (IV) to estimate the impact of obesity on medical costs in order to address the endogeneity of weight and to reduce the bias from reporting error in weight. Models are estimated using restricted-use data from the Medical Expenditure Panel Survey for 2000-2005. The IV model, which exploits genetic variation in weight as a natural experiment, yields estimates of the impact of obesity on medical costs that are considerably higher than the estimates reported in the previous literature. For example, obesity is associated with $656 higher annual medical care costs, but the IV results indicate that obesity raises annual medical costs by $2741 (in 2005 dollars). These results imply that the previous literature has underestimated the medical costs of obesity, resulting in underestimates of the economic rationale for government intervention to reduce obesity-related externalities.

Obesogenic family types identified through latent profile analysis

BACKGROUND

Obesity may cluster in families due to shared physical and social environments.

PURPOSE

This study aims to identify family typologies of obesity risk based on family environments.

METHODS

Using 2007-2008 data from 706 parent/youth dyads in Minnesota, we applied latent profile analysis and general linear models to evaluate associations between family typologies and body mass index (BMI) of youth and parents.

RESULTS

Three typologies described most families with 18.8% "Unenriched/Obesogenic," 16.9% "Risky Consumer," and 64.3% "Healthy Consumer/Salutogenic." After adjustment for demographic and socioeconomic factors, parent BMI and youth BMI Z-scores were higher in unenriched/obesogenic families (BMI difference = 2.7, p < 0.01 and BMI Z-score difference = 0.51, p < 0.01, respectively) relative to the healthy consumer/salutogenic typology. In contrast, parent BMI and youth BMI Z-scores were similar in the risky consumer families relative to those in healthy consumer/salutogenic type.

CONCLUSIONS

We can identify family types differing in obesity risks with implications for public health interventions.

Shortened sleep duration does not predict obesity in adolescents

Obesity continues to be a major public health issue. In adolescents, there are limited studies on the relationship between obesity and sleep duration. We found hypothesized that an average sleep duration of <6 h in adolescents was associated with obesity. Data were from the National Longitudinal Study of Adolescent Health (ADD Health); a survey of 90,000 youths, aged 12-18 years; surveyed in several waves. The sample population for our study was 13,568. Weighted multiple logistic regression was used to identify the relationship between obesity at Wave II and sleep duration, having adjusted for skipping breakfast ≥ 2/week; race, gender, parental income, TV ≥ 2 h per day, depression, and obesity at Wave I. At Wave I, the mean age was 15.96 ± 0.11 years; mean sleep hours were 7.91 ± 0.04. At Waves I and II, respectively, 10.6 and 11.2% of adolescents were obese. Adjusted analyses suggest that the effect of shortened sleep duration in Wave I was not significantly predictive of obesity in Wave II (P < 0.218). Longitudinally, depression and TV ≥ 2 h per day at Wave I was associated with a higher risk of obesity at Wave II in adjusted analyses. Depressed adolescents were almost twice as likely to be obese (OR = 1.84, 95% CI = 1.25-2.72); adolescents who watched TV ≥ 2 h per day were 37% more likely to be obese (OR = 1.37, 95% CI = 1.09-1.72). Environmental factors including TV ≥ 2 h per day and depression were significantly associated with obesity; shortened sleep duration was not. Future longitudinal studies in adolescents are needed to determine whether timing of television watching directly influences sleep patterns and, ultimately, obesity.

Sociodemographic and lifestyle characteristics in relation to dietary patterns among young Brazilian adults

OBJECTIVE

To identify dietary patterns among young adults and the relationships with socio-economic, demographic and lifestyle characteristics.

DESIGN

Population-based, cross-sectional analysis of a cohort study. Food intake was assessed by a frequency questionnaire, and dietary patterns were identified using principal components analysis.

SETTING

Southern Brazil.

SUBJECTS

A total of 4202 men and women aged 23 years, who participated in the 1982 Pelotas Birth Cohort Study.

RESULTS

Five dietary patterns were identified: common Brazilian, processed food, vegetable/fruit, dairy/dessert and tubers/pasta. Subjects who had low own or maternal educational levels, low social position or who were always poor throughout life had high adherence to the common Brazilian dietary pattern. In contrast, the processed food pattern was more likely to be followed by those belonging to middle and high social position and who were never poor. Men and smokers showed high adherence to the processed food and common Brazilian dietary patterns. Vegetable/fruit pattern was more likely to be followed by women and subjects engaged in physical activity. Women also showed high adherence to the dairy/dessert pattern.

CONCLUSIONS

Our study among young Brazilian adults has identified distinct dietary patterns that are clearly influenced by socio-economic and lifestyle characteristics, which have important policy implications in a country with marked social and economic inequalities.

Capability and clinical success

Better outcomes for chronic diseases remain elusive because success depends on events outside the control of the health care system: patients' ability to mange their health behaviors and chronic diseases. Among the most powerful influences on self-management are the social and environmental constraints on healthy living, yet the clinical response to these environmental determinants is poorly developed. A potential approach for addressing social determinants in practice, as well as planning and evaluating community responses, is the capability framework. Defined as the real opportunity to achieve a desired lifestyle, capability focuses attention on the material conditions that constrain real opportunity and how opportunity emerges from the interaction between personal resources and the social environment. Using examples relevant to chronic disease and behavior change, we discuss the clinical application of the capability framework.

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 > or =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 (rho(G)) = 0.61 +/- 0.03) and young adulthood (rho(G) = 0.23 +/- 0.06). Our findings support a complex etiology of BMI and BMI change.

Stable genes and changing environments: body mass index across adolescence and young adulthood

The transition between adolescence and young adulthood is a developmentally sensitive time where children are at an increased risk for becoming overweight and developing obesity. Twin studies have reported that body mass index [BMI] is highly heritable, however, it remains unclear whether the genetic influences are sex-limited and whether non-additive genetic influences contribute to body mass index [BMI] during these ages. In the current report, we examined self-reported data on BMI in same [n = 2,744] and opposite-sex [n = 1,178] siblings participating in the National Longitudinal Study on Adolescent Health [Add Health]. To investigate whether the same or different genes contributed to BMI for both sexes, we fit quantitative sex-limited genetic models to three waves of data collection. At each of the three Waves of assessment, models that included additive genetic, individual-specific environment, and no sex-limited genetic influences fit the data most parsimoniously. Heritable effects on BMI at each of the three Waves were large for both sexes and ranged between .75 and .86. While genetic contributions across the ages were highly correlated, longitudinal analyses indicated that the relevant individual-specific environmental influences on BMI in adolescence and young adulthood change sizably. These results underscore the importance of understanding early genetic influences on BMI and highlight the role environmental experiences have at later ages when new genetic influences appear to make a small contribution to individual variation in BMI.

Sitting time and body mass index, in a Portuguese sample of men: results from the Azorean Physical Activity and Health Study (APAHS)

The aim of this study was to verify the relation between body mass index (BMI) and sitting time in a sample of 4,091 Azorean men. BMI was calculated from self-reported weight and height. Total physical activity (PA) time and total sitting time were assessed with the IPAQ (short version). Linear Regression analysis showed that total sitting time (hours/day) was positively associated with BMI (B = 0.078; p < 0.001) after adjustments for age, meal frequency, alcohol and tobacco consumptions, island of residence, education level and total PA time. Although the cross sectional design precludes us from establishing causality, our findings emphasize the importance of reducing sedentary behavior to decrease the risk of obesity.

Ethnicity, body mass, and genome-wide data

This article combines social and genetic epidemiology to examine the influence of self-reported ethnicity on body mass index (BMI) among a sample of adolescents and young adults. We use genetic information from more than 5,000 single nucleotide polymorphisms in combination with principal components analysis to characterize population ancestry of individuals in this study. We show that non-Hispanic white and Mexican-American respondents differ significantly with respect to BMI and differ on the first principal component from the genetic data. This first component is positively associated with BMI and accounts for roughly 3% of the genetic variance in our sample. However, after controlling for this genetic measure, the observed ethnic differences in BMI remain large and statistically significant. This study demonstrates a parsimonious method to adjust for genetic differences among individual respondents that may contribute to observed differences in outcomes. In this case, adjusting for genetic background has no bearing on the influence of self-identified ethnicity.

Prediction of BMI change in young children with the family nutrition and physical activity (FNPA) screening tool

BACKGROUND

Youth obesity prevention practices would be enhanced if modifiable risk factors can be identified before children become overweight.

PURPOSE

This study evaluated the predictive validity of the Family Nutrition and Physical Activity (FNPA) screening tool, a behaviorally based screening tool designed to assess family environments and behaviors that may predispose youth to becoming overweight.

METHODS

Parents from a large urban school district completed the FNPA screening when children were in first grade. One-year change in measured body mass index (BMI) was used as the primary outcome, and this was computed using the relative change in distance from the BMI value at the 50th percentile. Descriptive, correlation, and mixed modeling analyses were used for survey validation.

RESULTS

Over half of the participants exhibited an increase in BMI percentile over the 1-year follow-up with an average change of 0.51 +/- 11.5% which is indicative of trends to overweight. Although baseline BMI predicted BMI at follow-up, the FNPA total score explained unique variance in child BMI at follow-up after accounting for baseline BMI, parent BMI, and other demographic variables (p = 0.049).

CONCLUSIONS

This study demonstrates the potential validity of a simple, easy-to-use screening tool for identifying children that may be at risk for becoming overweight.

Men develop more intraabdominal obesity and signs of the metabolic syndrome after hyperalimentation than women

We prospectively studied the effects of fast food-based hyperalimentation on insulin sensitivity and components of the metabolic syndrome and analyzed this with respect to sex. Twelve nonobese men and 6 nonobese women (26 +/- 6.6 years old), and an age-matched control group were recruited. Subjects in the intervention group aimed for 5% to 15% weight increase by doubling their regular caloric intake based on at least 2 fast food meals a day while also adopting a sedentary lifestyle for 4 weeks (<5000 steps a day). Weight of subjects in the intervention group increased from 67.6 +/- 9.1 to 74.0 +/- 11 kg (P < .001), with no sex difference with regard to this or with respect to changes of total abdominal fat volumes or waist circumferences. Fasting insulin (men: before, 3.8 +/- 1.7 microU/mL; after, 7.4 +/- 3.1 microU/mL; P = .004; women: before, 4.9 +/- 2.3 microU/mL; after, 5.9 +/- 2.8 microU/mL; P = .17), systolic blood pressure (men: before, 117 +/- 13 mm Hg; after, 127 +/- 9.1 mm Hg; P = .002; women: before, 102 +/- 5.1 mm Hg; after, 98 +/- 5.4 mm Hg; P = .39), serum low-density lipoprotein cholesterol, and apolipoprotein B increased only in the men of the intervention group. The sex differences in the metabolic responses to the intervention were linked to a considerable difference in the fat accumulation pattern; 41.4% +/- 9.2% of the increase of the fat volume in the abdominal region was accumulated intraabdominally in men and 22.7 +/- 6.5% in women (P < .0001). This study thus showed that women are protected, compared with men, against developing intraabdominal obesity when adopting a standardized obesity-provoking lifestyle. Our findings suggest that it is not different lifestyles and/or behaviors that underlie the fact that men have a higher cardiovascular risk at the same level of percentage of body fat than women.

Walking and body mass index in a Portuguese sample of adults: a multilevel analysis

Physical inactivity is an important risk factor for many chronic diseases. The purpose of this study was to investigate the cross-sectional associations between walking and body mass index (BMI). This study comprised 9991 adults (5723 women), aged 37.8+/-9.5 years, from the 2004 Azorean Physical Activity and Health Study. Walking was assessed with the International Physical Activity Questionnaire, and expressed as minutes per week. BMI was calculated from self-reported weight and height. A series of multilevel linear regression models were fitted to assess regression coefficients and s.e. predicting BMI. Results show that, in both genders, and after adjustments for potential confounders, walking was not a significant predictor of BMI. Therefore, our analysis does not extend the findings of earlier studies as it shows no significant associations between walking and BMI, after adjustments for potential confounders. Nevertheless, among Azoreans walking should be encouraged, as walking has other health benefits, beyond controlling obesity.

The female-male disparity in obesity prevalence among black American young adults: contributions of sociodemographic characteristics of the childhood family

BACKGROUND

In the United States, black women are at much greater risk of obesity than are black men. Little is known about the factors underlying this disparity.

OBJECTIVE

We explored whether childhood sociodemographic factors (parental education, single-mother household, number of siblings, number of minors in household, birth order, and female caregiver's age) were associated with the gender disparity in obesity prevalence in young black adults in the United States.

DESIGN

An analytic data set (n = 7747) was constructed from the nationally representative National Longitudinal Study of Adolescent Health. Childhood sociodemographic factors were assessed in 1994-1995 in nonimmigrant black and white youths aged 11-19 y. Obesity was assessed in 2001-2002. For each childhood sociodemographic factor, we evaluated whether the prevalence difference (female obesity minus male obesity) was modified by the factor. We described the contribution of each variable category to the overall prevalence difference.

RESULTS

In unadjusted and multivariable-adjusted models, parental education consistently modified gender disparity in blacks (P = 0.01). The gender gap was largest with low parental education (16.7% of men compared with 45.4% of women were obese) and smallest with high parental education (28.5% of men compared with 31.4% of women were obese). In whites, there was little overall gender difference in obesity prevalence.

CONCLUSIONS

To our knowledge, this was the first study to document that the gender disparity in obesity prevalence in young black adults is concentrated in families with low parental education. In these low-socioeconomic-status families, obesity development is either under the control of distinct mechanisms in each gender, or men and women from these households adopt different obesity-related behaviors.

Parent-reported eating and leisure-time activity selection patterns related to energy balance in preschool- and school-aged children

OBJECTIVE

Compare parent-reported preschool- and school-aged children's eating and leisure-time activity patterns that are proposed to influence energy balance.

DESIGN

Cross-sectional investigation of children, 2 to 12 years, attending a well visit.

SETTING

Pediatric private practice/ambulatory pediatric clinic.

PARTICIPANTS

One hundred seventy-four children: 49% preschool-aged, 54% female, 28% Hispanic, and 34% overweight or at risk for overweight.

VARIABLES MEASURED

Parent-reported eating/leisure-time behaviors. Height/weight from medical records.

ANALYSIS

Analyses of covariance/chi-square tests; significance at P

RESULTS

By parents' report, preschool-aged children consumed more servings/day of low-fat dairy (2.1 +/- 1.6 vs 1.7 +/- 1.5; P < .01), fewer servings/day of sweetened drinks (1.4 +/- 1.9 vs 2.2 +/- 2.6; P < .01) and watched fewer hours/day of weekend TV (2.3 +/- 1. 3 vs 2.7 +/- 1.3; P < .05) than school-aged children. Fewer preschool-aged children consumed salty (14.0% vs 26.1%; P < .05) and sweet (16.3% vs. 29.5%; P < .05) snack food daily, and a greater percentage regularly consumed dinner with a parent (93.0% vs 80.7%; P < .05), as assessed by parent report.

CONCLUSIONS AND IMPLICATIONS

Parent-reported children's eating/leisure-time patterns that may influence energy balance were less healthful in the school-aged children. However, most children did not meet recommendations, irrespective of age or weight. Interventions for meeting recommendations should start with families with preschool-aged children. Future research should focus on identifying factors that might be contributing to increased reporting of problematic food and leisure-time activity patterns in school-aged children.

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Key Words

• children
• preschool
• diet
• leisure-time
• obesity

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MESH Headings

• Age Distribution
• Ambulatory Care Facilities
• Analysis of Variance
• Child
• Child, Preschool
• Cross-Sectional Studies
• Energy Intake/physiology
• Energy Metabolism/physiology
• Feeding Behavior/ethnology
• Feeding Behavior/physiology
• Feeding Behavior/psychology
• Female
• Humans
• Leisure Activities/psychology
• Male
• Overweight/etiology
• Parents
• Pediatrics
• Surveys and Questionnaires

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Grants

• R21 DK074919-01 NIDDK NIH HHS
• R21 DK074919-02 NIDDK NIH HHS
• R21 DK074919-03 NIDDK NIH HHS
• R21 DK074919 NIDDK NIH HHS
• DK074919 NIDDK NIH HHS

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Affiliation(s)

Hollie A Raynor Department of Nutrition, University of Tennessee, Knoxville, Tennessee 37996, USA.
Elissa Jelalian
Patrick M Vivier
Chantelle N Hart
Rena R Wing

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Behavioral science and the study of gene-nutrition and gene-physical activity interactions in obesity research

This report summarizes emerging opportunities for behavioral science to help advance the field of gene-environment and gene-behavior interactions, based on presentations at The National Cancer Institute (NCI) Workshop, "Gene-Nutrition and Gene-Physical Activity Interactions in the Etiology of Obesity." Three opportunities are highlighted: (i) designing potent behavioral "challenges" in experiments, (ii) determining viable behavioral phenotypes for genetics studies, and (iii) identifying specific measures of the environment or environmental exposures. Additional points are underscored, including the need to incorporate novel findings from neuroimaging studies regarding motivation and drive for eating and physical activity. Advances in behavioral science theory and methods can play an important role in advancing understanding of gene-brain-behavior relationships in obesity onset.

Fast food consumption and increased caloric intake: a systematic review of a trajectory towards weight gain and obesity risk

Consumption of fast food, which have high energy densities and glycemic loads, and expose customers to excessive portion sizes, may be greatly contributing to and escalating the rates of overweight and obesity in the USA. Whether an association exists between fast food consumption and weight gain is unclear. Sixteen studies (six cross sectional, seven prospective cohort, three experimental) meeting methodological and relevance criteria were selected for inclusion in this systematic review. While more research needs to be conducted specifically in regard to effects of fast food consumption among subpopulations such as children and adolescents, sufficient evidence exists for public health recommendations to limit fast food consumption and facilitate healthier menu selection. As the fast food industry continues to increase both domestically and abroad, the scientific findings and corresponding public health implications of the association between fast food consumption and weight are critical.

Genetic analysis of self-reported physical activity and adiposity: the Southwest Ohio Family Study

OBJECTIVE

Physical inactivity poses a major risk for obesity and chronic disease, and is influenced by both genetic and environmental factors. However, the genetic association between physical activity (PA) level and obesity is not well characterized. Our aims were to: (i) estimate the extent of additive genetic influences on physical activity while adjusting for household effects; and (ii) determine whether physical activity and adiposity measures share common genetic effects.

SUBJECTS

The sample included 521 (42 % male) adult relatives, 18-86 years of age, from five large families in the Southwest Ohio Family Study.

DESIGN

Sport, leisure and work PA were self-reported (Baecke Questionnaire of Habitual Physical Activity). Total body and trunk adiposity, including percentage body fat (%BF), were measured using dual-energy X-ray absorptiometry. Abdominal visceral and subcutaneous adipose tissue mass were measured using MRI.

RESULTS

Heritabilities for adiposity and PA traits, and the genetic, household and environmental correlations among them, were estimated using maximum likelihood variance components methods. Significant genetic effects (P < 0.05) were found for sport (h2 = 0.26) and leisure PA (h2 = 0.17). Significant (P < 0.05) household effects existed for leisure PA (c2 = 0.25). Sport PA had a negative genetic correlation with central adiposity measurements adjusted for height (rhoG > |-0.40|). Sport and leisure PA had negative genetic correlations with %BF (rhoG > |-0.46|).

CONCLUSIONS

The results suggest that the association of sport and leisure PA with lower adiposity is due, in part, to a common genetic inheritance of both reduced adiposity and the predisposition to engage in more physical activity.