Plus Size
Obesity and All-Cause Mortality Among Black Adults and White Adults
Sarah Cohen et al.
American Journal of Epidemiology, forthcoming
Abstract:
In recent pooled analyses among whites and Asians, mortality was shown to rise markedly with increasing body mass index (BMI; weight (kg)/height (m)2), but much less is known about this association among blacks. This study prospectively examined all-cause mortality in relation to BMI among 22,014 black males, 9,343 white males, 30,810 black females, and 14,447 white females, aged 40-79 years, from the Southern Community Cohort Study, an epidemiologic cohort of largely low-income participants in 12 southeastern US states. Participants enrolled in the cohort from 2002 to 2009 and were followed up to 8.9 years. Hazard ratios and 95% confidence intervals for mortality were obtained from sex- and race-stratified Cox proportional hazards models in association with BMI at cohort entry, adjusting for age, education, income, cigarette smoking, and alcohol consumption. Elevated BMI was associated with increased mortality among whites (hazard ratios for BMI >40 vs. 20-24.9 = 1.37 (95% confidence interval (CI): 1.02, 1.84) and 1.47 (95% CI: 1.15, 1.89) for white males and white females, respectively) but not significantly among blacks (hazard ratios = 1.13 (95% CI: 0.89, 1.43) and 0.87 (95% CI: 0.72, 1.04) for black males and black females, respectively). In this large cohort, obesity in mid-to-late adulthood among blacks was not associated with the same excess mortality risk seen among whites.
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James Kirby et al.
American Journal of Public Health, August 2012, Pages 1572-1578
Objectives: We explored the association between community racial/ethnic composition and obesity risk.
Methods: In this cross-sectional study, we used nationally representative data from the Medical Expenditure Panel Survey linked to geographic data from the US Decennial Census and Census Business Pattern data.
Results: Living in communities with a high Hispanic concentration (≥ 25%) was associated with a 0.55 and 0.42 increase in body mass index (BMI; defined as weight in kilograms divided by the square of height in meters) and 21% and 23% higher odds for obesity for Hispanics and non-Hispanic Whites, respectively. Living in a community with a high non-Hispanic Asian concentration (≥ 25%) was associated with a 0.68 decrease in BMI and 28% lower odds for obesity for non-Hispanic Whites. We controlled for individual- and community-level social, economic, and demographic variables.
Conclusions: Community racial/ethnic composition is an important correlate of obesity risk, but the relationship differs greatly by individual race/ethnicity. To better understand the obesity epidemic and related racial/ethnic disparities, more must be learned about community-level risk factors, especially how built environment and social norms operate within communities and across racial/ethnic groups.
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"The mind is willing, but the flesh is weak": The effects of mind-body dualism on health behavior
Matthias Forstmann, Pascal Burgmer & Thomas Mussweiler
Psychological Science, forthcoming
Abstract:
Beliefs in mind-body dualism - i.e., perceiving one's mind and body as two distinct entities - are evident among virtually all human cultures. Despite their prevalence, surprisingly little is known about the psychological implications of holding such beliefs. The current research investigated the relationship between dualistic beliefs and health behavior. We theorized that dualism leads people to perceive their body as a mere ‘shell' and, thus, to neglect that body. Supporting this hypothesis, participants who were primed with dualism (vs. physicalism) reported less engagement in healthy behaviors and less positive attitudes toward such behaviors. Additionally, the bidirectionality of this link was investigated. Activating health-related concepts affected participants' subsequently reported metaphysical beliefs in mind-body dualism. A final set of studies demonstrated that participants primed with dualism make real-life decisions that may ultimately compromise their physical health (e.g., consuming unhealthy food). We conclude by discussing potential implications for health interventions.
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Sedentary behaviour and life expectancy in the USA: A cause-deleted life table analysis
Peter Katzmarzyk & I-Min Lee
BMJ Open, July 2012
Objectives: To determine the impact of sitting and television viewing on life expectancy in the USA.
Design: Prevalence-based cause-deleted life table analysis.
Setting: Summary RRs of all-cause mortality associated with sitting and television viewing were obtained from a meta-analysis of available prospective cohort studies. Prevalences of sitting and television viewing were obtained from the US National Health and Nutrition Examination Survey.
Primary outcome measure: Life expectancy at birth.
Results: The estimated gains in life expectancy in the US population were 2.00 years for reducing excessive sitting to <3 h/day and a gain of 1.38 years from reducing excessive television viewing to <2 h/day. The lower and upper limits from a sensitivity analysis that involved simultaneously varying the estimates of RR (using the upper and lower bounds of the 95% CI) and the prevalence of television viewing (±20%) were 1.39 and 2.69 years for sitting and 0.48 and 2.51 years for television viewing, respectively.
Conclusion: Reducing sedentary behaviours such as sitting and television viewing may have the potential to increase life expectancy in the USA.
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Body mass index and central adiposity are associated with sperm quality in men of subfertile couples
Fatima Hammiche et al.
Human Reproduction, August 2012, Pages 2365-2372
Background: The incidence of overweight and obesity in men of reproductive ages is rising, which may affect fertility. Therefore, this study aims to assess the associations between BMI, central adiposity and sperm parameters in men of subfertile couples.
Methods: Ejaculate volume (ml), sperm concentration (millions per ml), percentage of progressive motile and immotile spermatozoa and total motile sperm count (millions) were measured in 450 men of subfertile couples visiting a tertiary outpatient clinic for reproductive treatment and preconception counseling.
Results: Overweight was negatively associated with the percentage of progressive motility type A [β -0.32 (SE 0.2), P = 0.036] and positively associated with the percentage of immotility type C [β 0.21 (SE 0.07), P = 0.002]. Obesity was negatively associated with ejaculate volume [β -0.23 (SE 0.1), P = 0.02], sperm concentration [β -0.77 (SE 0.3), P = 0.006] and total motile sperm count [β -0.91 (SE 0.3), P = 0.007]. Waist circumference ≥102 cm, a measure for central adiposity, was inversely associated with sperm concentration [β -0.69 (SE 0.2), P = 0.001] and total motile sperm count [β -0.62 (SE 0.3), P = 0.02]. All associations remained significant after adjustment for age, ethnicity, active and passive smoking, alcohol and medication use and folate status.
Conclusions: This study shows that in particular, sperm concentration and total motile sperm count in men of subfertile couples are detrimentally affected by a high BMI and central adiposity. The effect of weight loss on sperm quality and fertility needs further investigation.
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Weight stigma, addiction, science, and the medication of fatness in mid-twentieth century America
Nicolas Rasmussen
Sociology of Health & Illness, July 2012, Pages 880-895
Abstract:
Obesity and overweight are today recognised as subject to harmful stigma. Through an analysis of discussions of obesity in major American newspapers, the medical literature, and pharmaceutical advertising in the 1930s, 1940s and 1950s, I document a significant shift in medical thinking about overweight and obesity based in psychiatry, and explore the relationship of that shift to changes in popular understandings of fatness after the Second World War. I argue that the psychiatrically-oriented postwar medical thinking about obesity was more stigmatising as compared with the endocrinologically-oriented thinking of the interwar period, in that the newer biomedical theory linked fatness to the already stigmatised condition of addiction and authorised attribution of moral blame to the fat. I further argue that the pharmaceutical industry cannot be assigned the lead role in medicalisation in this period that some authors attributed to it. These events cast doubt on the received view of fatness as subject to decreasing stigma and increasing medicalisation over the course of the twentieth century, and call for exploration of the social factors influencing specific forms of medicalisation.
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Evidence on the Efficacy of School-Based Incentives for Healthy Living
H.E. Cuffe et al.
Economics of Education Review, forthcoming
Abstract:
We analyze the effects of a school-based program that offers children an opportunity to win prizes if they walk or bike to school during prize periods. We use daily child-level data and individual fixed effects models to measure the effect of the prizes, with variation in the timing of prize periods across different schools allowing us to estimate models with calendar-date fixed effects to control for day-specific attributes, such as weather and proximity to holidays. On average, we find that being in a prize period increases the riding behavior of participating children by sixteen percent, a large impact given that the prize value is just six cents per student. We also find that winning a prize lottery has a positive impact on ridership over subsequent weeks; consider heterogeneity across prize type, gender, age, and calendar month; and explore differential effects on the intensive versus extensive margins.
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Per Gustafsson et al.
PLoS ONE, June 2012
Abstract:
While the importance of social relations for health has been demonstrated in childhood, adolescence and adulthood, few studies have examined the prospective importance of peer relations for adult health. The aim of this study was to examine whether peer problems in the school setting in adolescence relates to the metabolic syndrome in middle-age. Participants came from the Northern Swedish Cohort, a 27-year cohort study of school leavers (effective n = 881, 82% of the original cohort). A score of peer problems was operationalized through form teachers' assessment of each student's isolation and popularity among school peers at age 16 years, and the metabolic syndrome was measured by clinical measures at age 43 according to established criteria. Additional information on health, health behaviors, achievement and social circumstances were collected from teacher interviews, school records, clinical measurements and self-administered questionnaires. Logistic regression was used as the main statistical method. Results showed a dose-response relationship between peer problems in adolescence and metabolic syndrome in middle-age, corresponding to 36% higher odds for the metabolic syndrome at age 43 for each SD higher peer problems score at age 16. The association remained significant after adjustment for health, health behaviors, school adjustment or family circumstances in adolescence, and for psychological distress, health behaviors or social circumstances in adulthood. In analyses stratified by sex, the results were significant only in women after adjustment for covariates. Peer problems were significantly related to all individual components of the metabolic syndrome. These results suggest that unsuccessful adaption to the school peer group can have enduring consequences for metabolic health.
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Population heterogeneity in the impact of body weight on mortality
Hui Zheng & Yang Yang
Social Science & Medicine, September 2012, Pages 990-996
Abstract:
Existing research provides inconsistent evidence for a relationship between overweight and/or obesity and mortality, and poorly studies the population heterogeneity with respect to the mortality consequence of overweight/obesity. This study investigates how overweight and/or obesity affect mortality and how these effects may vary across sociodemographic groups defined by race, sex, age, education and income by using the U.S. Third National Health and Nutrition Examination Survey (NHANES III) with linked mortality data from 1988 to 2006 (6915 respondents with 2694 deaths). Analysis from Cox proportional hazard model suggests overweight people are at lower risk of death compared to normal weight people, but this protection effect is concentrated in black men, older adults, and people in the lowest income stratum. Class I obesity does not increase mortality risk, but Class II/III obesity does and the harmful effect is concentrated in whites, young and middle adults, and people with higher education and income levels. We discuss these findings in the context of the extant literature and the long-term prospect of life expectancy in the U.S.
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Obesity and socioeconomic status in developing countries: A systematic review
G.D. Dinsa et al.
Obesity Reviews, forthcoming
Abstract:
We undertook a systematic review of studies assessing the association between socioeconomic status (SES) and measured obesity in low- and middle-income countries (defined by the World Bank as countries with per capita income up to US$12,275) among children, men and women. The evidence on the subject has grown significantly since an earlier influential review was published in 2004. We find that in low-income countries or in countries with low human development index (HDI), the association between SES and obesity appears to be positive for both men and women: the more affluent and/or those with higher educational attainment tend to be more likely to be obese. However, in middle-income countries or in countries with medium HDI, the association becomes largely mixed for men and mainly negative for women. This particular shift appears to occur at an even lower level of per capita income than suggested by an influential earlier review. By contrast, obesity in children appears to be predominantly a problem of the rich in low- and middle-income countries.
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Obesity and Supermarket Access: Proximity or Price?
Adam Drewnowski et al.
American Journal of Public Health, August 2012, Pages e74-e80
Objectives: We examined whether physical proximity to supermarkets or supermarket price was more strongly associated with obesity risk.
Methods: The Seattle Obesity Study (SOS) collected and geocoded data on home addresses and food shopping destinations for a representative sample of adult residents of King County, Washington. Supermarkets were stratified into 3 price levels based on average cost of the market basket. Sociodemographic and health data were obtained from a telephone survey. Modified Poisson regression was used to test the associations between obesity and supermarket variables.
Results: Only 1 in 7 respondents reported shopping at the nearest supermarket. The risk of obesity was not associated with street network distances between home and the nearest supermarket or the supermarket that SOS participants reported as their primary food source. The type of supermarket, by price, was found to be inversely and significantly associated with obesity rates, even after adjusting for individual-level sociodemographic and lifestyle variables, and proximity measures (adjusted relative risk = 0.34; 95% confidence interval = 0.19, 0.63)
Conclusions: Improving physical access to supermarkets may be one strategy to deal with the obesity epidemic; improving economic access to healthy foods is another.
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Smoking Cessation and Body Weight: Evidence from the Behavioral Risk Factor Surveillance Survey
Panagiotis Kasteridis & Steven Yen
Health Services Research, August 2012, Pages 1580-1602
Objective: To investigate the role of smoking cessation in body weight.
Data Sources: 2004-2005 and 2009-2010 Behavioral Risk Factor Surveillance Surveys (BRFSS) (N = 349,000), Centers for Disease Control and Prevention; Tax Burden on Tobacco (Orzechowski and Walker 2010).
Study Design: The Gaussian treatment effect model is estimated for three age categories by gender. Treatment effects of quitting smoking on body mass index (BMI) by quit length are calculated.
Principal Findings: Quitting is found to be endogenous. Differentiated effects of quitting smoking on BMI are found among quitters by gender, between age groups, and by length of time since quitting smoking, and positive association between smoking cessation and body weight confirmed. Declining smoking rates have only a modest effect in the overweight population. The effects of quitting on BMI are considerably lower among younger men and women.
Conclusion: The price that must be paid, in terms of weight gain, to enjoy the health benefits of smoking cessation is trivial even for the obese population.
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Mauno Vanhala et al.
American Journal of Epidemiology, forthcoming
Abstract:
The serum fatty acid composition reflects the dietary fatty acid composition from the past few days to several weeks. However, the role of serum omega-3 (from fish and fish oils) and omega-6 (from vegetable oils) polyunsaturated fatty acids (PUFAs) in the course of metabolic syndrome is poorly understood. At the Primary Health Care Unit in Pieksämäki, Finland, all subjects born in 1942, 1947, 1952, 1957, and 1962 (n = 1,294) were invited for health checkups in 1997-1998 and 2003-2004. Metabolic syndrome was defined by using the new, harmonized criteria. The serum omega-3 PUFAs, omega-6 PUFAs, and total fatty acids were analyzed by proton nuclear magnetic resonance spectroscopy. Altogether, data from both checkups were available for 665 subjects. After adjustment for age, sex, and baseline body mass index, the incidence of metabolic syndrome between the 2 checkups with a 6.4-year follow-up was inversely associated (P < 0.001) with the increased relative proportion of omega-6 PUFAs in serum lipids. Further adjustment for body mass index change, lipid medication, smoking, alcohol intake, and physical activity conveyed similar results. The authors did not find any significant associations between omega-3 PUFAs and the incidence of metabolic syndrome. Therefore, their results suggest that the change in the relative proportion of omega-6 PUFAs in serum lipids is inversely related to the incidence of metabolic syndrome.
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Scott Alan Carson
Mathematical Population Studies, Summer 2012, Pages 147-157
Abstract:
Little research exists on the body mass index (BMI) values of nineteenth-century Americans of European descent. Examination of a new body mass index data set and robust statistical analysis yields the following conclusion: between 1860 and 1880, BMIs decreased across the distribution; however, after 1880, BMIs in the highest quantiles increased, while those in lower BMI quantiles continued to decrease. Late nineteenth- and early twentieth-century white BMIs increased at older ages in higher quantiles and decreased in lower quantiles, indicating significant net biological disparity by age. During industrialization, white BMIs were lower in Kentucky, Missouri, and urban Philadelphia.
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Early education and health outcomes using the U.S. Early childhood longitudinal study-birth cohort
Clive Belfield & Inas Rashad Kelly
Economics & Human Biology, forthcoming
Abstract:
This paper looks at health outcomes, health behaviors, and health screening with respect to participation in Early Childhood Care and Education. With information on health status at multiple periods in time, we are able to look at whether healthier children select into early childhood education (as measured by center-based preschool care and Head Start), as well as whether early childhood education has immediate and near-term effects on a range of health status measures. There is some evidence that child obesity is ameliorated by participation in center-based preschool or Head Start and this finding is supported by clear evidence of improved nutrition and increased levels of health screening. Effects on other health outcomes such as asthma, ear infections, and respiratory problems may be partially masked by unobserved heterogeneity.
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Mitzi Gonzales et al.
Psychosomatic Medicine, forthcoming
Objective: Elevated body mass index (BMI) at midlife is associated with increased risk of cognitive decline in later life. The goal of the current study was to assess mechanisms of early brain vulnerability by examining if higher BMI at midlife affects current cognitive performance through alterations in cerebral neurochemistry.
Methods: Fifty-five participants, aged 40 to 60 years, underwent neuropsychological testing, health screen, and proton magnetic resonance spectroscopy examining N-acetylaspartate, creatine (Cr), myo-inositol (mI), choline, and glutamate concentrations in occipitoparietal gray matter. Concentrations of N-acetylaspartate, choline, mI, and glutamate were calculated as a ratio over Cr and examined in relation to BMI using multivariate regression analyses. Structural equation modeling was used to determine if BMI had an indirect effect on cognition through cerebral metabolite levels.
Results: Higher BMI was associated with elevations in mI/Cr (F(5,45) = 3.843, p = .006, β = 0.444, p = .002), independent of age, sex, fasting glucose levels, and systolic blood pressure. Moreover, a χ2 difference test of the direct and indirect structural equation models revealed that BMI had an indirect effect on global cognitive performance (Δχ2 = 19.939, df = 2, p < .001). Subsequent follow-up analyses revealed that this effect was specific to memory (Δχ2 = 22.027, df = 2, p < .001).
Conclusions: Higher BMI was associated with elevations in mI/Cr concentrations in the occipitoparietal gray matter and indirectly related to poorer memory performance through mI/Cr levels, potentially implicating plasma hypertonicity and neuroinflammation as mechanisms underlying obesity-related brain vulnerability.
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Jessica Bolton et al.
Journal of the Federation of American Societies for Experimental Biology, forthcoming
Abstract:
Emerging evidence suggests environmental chemical exposures during critical windows of development may contribute to the escalating prevalence of obesity. We tested the hypothesis that prenatal air pollution exposure would predispose the offspring to weight gain in adulthood. Pregnant mice were exposed to filtered air (FA) or diesel exhaust (DE) on embryonic days (E) 9-17. Prenatal DE induced a significant fetal brain cytokine response at E18 (46-390% over FA). As adults, offspring were fed either a low-fat diet (LFD) or high-fat diet (HFD) for 6 wk. Adult DE male offspring weighed 12% more and were 35% less active than FA male offspring at baseline, whereas there were no differences in females. Following HFD, DE males gained weight at the same rate as FA males, whereas DE females gained 340% more weight than FA females. DE-HFD males had 450% higher endpoint insulin levels than FA-HFD males, and all males on HFD showed decreased activity and increased anxiety, whereas females showed no differences. Finally, both DE males and females fed HFD showed increased microglial activation (30-66%) within several brain regions. Thus, prenatal air pollution exposure can "program" offspring for increased susceptibility to diet-induced weight gain and neuroinflammation in adulthood in a sex-specific manner.
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Obesity Prevention: The Impact of Local Health Departments
Zhuo (Adam) Chen, Kakoli Roy & Carol Gotway Crawford
Health Services Research, forthcoming
Objective: To examine the association between bodyweight status and provision of population-based prevention services.
Data Sources: The National Association of City and County Health Officials 2005 Profile survey data, linked with two cross-sections of the Behavioral Risk Factor Surveillance System (BRFSS) survey in 2004 and 2005.
Study Design: Multilevel logistic regressions were used to examine the association between provision of obesity-prevention services and the change in risk of being obese or morbidly obese among BRFSS respondents. The estimation sample was stratified by sex. Low-income samples were also examined. Falsification tests were used to determine whether there is counterevidence.
Principal Findings: Provision of population-based obesity-prevention services within the jurisdiction of local health departments and specifically those provided by the local health departments are associated with reduced risks of obesity and morbid obesity from 2004 to 2005. The magnitude of the association appears to be stronger among low-income populations and among women. Results of the falsification tests provide additional support of the main findings.
Conclusions: Population-based obesity-prevention services may be useful in containing the obesity epidemic.