Full Figure
The Interplay between Gender, Race and Weight Status: Self Perceptions and Social Consequences
Jason Fletcher
Economics & Human Biology, forthcoming
Abstract:
This paper uses data from nearly 15,000 young adult respondents to the Add Health survey to examine racial and gender differences in the perceptions and social rewards to weight. The data include information on several typically unmeasured domains: self-perceptions of ideal weight, attractiveness ratings, and measured weight information, along with ties to a series of adult outcomes. Results show important gender and racial differences in ideal weight as well as differences for both self-perceived attractiveness and interviewer rated attractiveness. Findings also suggest the existence of large differences in socio-cultural rewards and sanctions for weight status. Black respondents, particularly women, appear to receive lower "obesity penalties" in both their self-perceived and interviewer accessed attractiveness ratings than other groups. These findings suggest the need to consider new classes of policies directed at shifting relative social benefits and consequences to weight status.
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Emily Hayes et al.
PLoS ONE, March 2012
Abstract:
Maternal obesity results in a number of obstetrical and fetal complications with both immediate and long-term consequences. The increased prevalence of obesity has resulted in increasing numbers of women of reproductive age in this high-risk group. Since many of these obese women have been subjected to hypercaloric diets from early childhood we have developed a rodent model of life-long maternal obesity to more clearly understand the mechanisms that contribute to adverse pregnancy outcomes in obese women. Female Sprague Dawley rats were fed a control diet (CON - 16% of calories from fat) or high fat diet (HF - 45% of calories from fat) from 3 to 19 weeks of age. Prior to pregnancy HF-fed dams exhibited significant increases in body fat, serum leptin and triglycerides. A subset of dams was sacrificed at gestational day 15 to evaluate fetal and placental development. The remaining animals were allowed to deliver normally. HF-fed dams exhibited a more than 3-fold increase in fetal death and decreased neonatal survival. These outcomes were associated with altered vascular development in the placenta, as well as increased hypoxia in the labyrinth. We propose that the altered placental vasculature may result in reduced oxygenation of the fetal tissues contributing to premature demise and poor neonatal survival.
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Margarete Vollrath, Sarah Hampson & Pétur Júlíusson
Appetite, June 2012, Pages 1113-1117
Abstract:
The role of children's personality traits in the consumption of potentially obesogenic foods was investigated in a sample of Norwegian children aged 6-12 years (N = 327, 170 boys, 157 girls). Mothers rated their child's personality on the traits of the Five Factor Model (i.e., extraversion, benevolence, conscientiousness, neuroticism, and imagination). Mothers also completed a food frequency questionnaire assessing their child's consumption of sweet drinks, sweet foods, and fruit and vegetables, and reported their child's height and weight. Controlling for age and mothers' education, boys and girls who were less benevolent consumed more sweet drinks, and girls who were less conscientious and more neurotic consumed more sweet drinks. Boys and girls who were more benevolent and imaginative consumed more fruits and vegetables, and boys who were more extraverted, more conscientious, and less neurotic consumed more fruits and vegetables. Controlling for maternal education, boys and girls who were less extraverted, and girls who were less benevolent, less conscientious, and more neurotic were more likely to be overweight or obese. These findings suggest that children's personality traits play an important yet understudied role in their diet. Further investigation of mechanisms that relate child traits to obesogenic eating and overweight would be valuable.
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Sarah Elizabeth Gollust, Ijeoma Eboh & Colleen Barry
Social Science & Medicine, forthcoming
Abstract:
News media coverage can affect how Americans view health policy issues. While previous research has investigated the text content of news media coverage of obesity, these studies have tended to ignore the photographs and other images that accompany obesity-related news coverage. Images can convey important messages about which groups in society are more or less affected by a health problem, and, in turn, shape public understanding about the social epidemiology of that condition. In this study, we analyzed the images of overweight and obese individuals in Time and Newsweek coverage over a 25-year period (1984-2009), and compared these depictions, which we characterize as representing the "news media epidemiology" of obesity, to data describing the true national prevalence of obesity within key populations of interest over this period. Data collected included descriptive features of news stories and accompanying images, and demographic characteristics of individuals portrayed in images. Over the 25-year period, we found that news magazines increasingly depicted non-whites as overweight and obese, and showed overweight and obese individuals less often performing stereotypical behaviors. Even with increasing representation of non-whites over time, news magazines still under-represented African Americans and Latinos. In addition, the elderly were starkly under-represented in images of the overweight and obese compared to actual prevalence rates. Research in other policy arenas has linked media depictions of the populations affected by social problems with public support for policies to combat them. Further research is needed to understand how news media depictions can affect public stigma toward overweight and obese individuals and public support for obesity prevention efforts.
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Association between More Frequent Chocolate Consumption and Lower Body Mass Index
Beatrice Golomb, Sabrina Koperski & Halbert White
Archives of Internal Medicine, 26 March 2012, Pages 519-521
"Adults who consumed chocolate more frequently had a lower BMI than those who consumed chocolate less often. The findings were retained or strengthened in a range of adjustment models and was not explained by calorie intake (frequent chocolate intake was linked to more overall calories), activity, or other assessed potential confounders...Cocoa-derived epicatechin, specifically, is reported to increase mitochondrial biogenesis and capillarity, muscular performance, and lean muscle mass and to reduce weight without changing calories or exercise in rodent studies. Parallel processes in humans, if present, could underlie our findings."
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Thinness and obesity: A model of food consumption, health concerns, and social pressure
Davide Dragone & Luca Savorelli
Journal of Health Economics, January 2012, Pages 243-256
Abstract:
The increasing concern of the policy maker about eating behaviour has focused on the spread of obesity and on the evidence of people dieting despite being underweight. As the latter behaviour is often attributed to the social pressure to be thin, some governments have already taken actions to ban ultra-thin ideals and models. This paper proposes a theoretical framework to assess whether increasing the ideal body weight is socially desirable, both from a welfare and a health point of view. We first show that being underweight and being overweight are possible outcomes of a rational eating model. Then, assuming that people are heterogeneous in their healthy weights but exposed to the same ideal body weight, we show that increasing the thin ideal weight can be welfare improving, but may exacerbate the obesity epidemic.
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Obesity: A disease or a biological adaptation? An update
J.-P. Chaput, É. Doucet & A. Tremblay
Obesity Reviews, forthcoming
Abstract:
Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. An important challenge of today's world is that our so-called obesogenic environment is conducive to the consumption of energy and unfavourable to the expenditure of energy. The modern, computer-dependent, sleep-deprived, physically inactive humans live chronically stressed in a society of food abundance. From a physiological standpoint, the excess weight gain observed in prone individuals is perceived as a normal consequence to a changed environment rather than a pathological process. In other words, weight gain is a sign of our contemporary way of living or a ‘collateral damage' in the physiological struggle against modernity. Additionally, substantial body fat loss can complicate appetite control, decrease energy expenditure to a greater extent than predicted, increase the proneness to hypoglycaemia and its related risk towards depressive symptoms, increase the plasma and tissue levels of persistent organic pollutants that promote hormone disruption and metabolic complications, all of which are adaptations that can increase the risk of weight regain. In contrast, body fat gain generally provides the opposite adaptations, emphasizing that obesity may realistically be perceived as an a priori biological adaptation for most individuals. Accordingly, prevention and treatment strategies for obesity should ideally target the main drivers or root causes of body fat gain in order to be able to improve the health of the population.
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"Split Them!" Smaller Item Sizes of Cookies Lead to a Decrease in Energy Intake in Children
David Marchiori, Laurent Waroquier & Olivier Klein
Journal of Nutrition Education and Behavior, forthcoming
Objective: Examine the influence of altering the size of snack food (ie, small vs large cookies) on short-term energy intake.
Methods: First- and sixth-graders (n = 77) participated in a between-subjects experimental design. All participants were offered the same gram weight of cookies during an afternoon tea at their school. For half of the participants, food was cut in 2 to make the small item size. Food intake (number of cookies, gram weight, and energy intake) was examined using ANOVA.
Results: Decreasing the item size of food led to a decrease of 25% in gram weight intake, corresponding to 68 kcal. Appetitive ratings and subject and food characteristics had no moderating effect.
Conclusions and Implications: Reducing the item size of food could prove a useful dietary prevention strategy based on decreased consumption, aimed at countering obesity-promoting eating behaviors favored by the easy availability of large food portions.
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Ching-Yu Cheng et al.
PLoS ONE, March 2012
Abstract:
The risk of type 2 diabetes is approximately 2-fold higher in African Americans than in European Americans even after adjusting for known environmental risk factors, including socioeconomic status (SES), suggesting that genetic factors may explain some of this population difference in disease risk. However, relatively few genetic studies have examined this hypothesis in a large sample of African Americans with and without diabetes. Therefore, we performed an admixture analysis using 2,189 ancestry-informative markers in 7,021 African Americans (2,373 with type 2 diabetes and 4,648 without) from the Atherosclerosis Risk in Communities Study, the Jackson Heart Study, and the Multiethnic Cohort to 1) determine the association of type 2 diabetes and its related quantitative traits with African ancestry controlling for measures of SES and 2) identify genetic loci for type 2 diabetes through a genome-wide admixture mapping scan. The median percentage of African ancestry of diabetic participants was slightly greater than that of non-diabetic participants (study-adjusted difference = 1.6%, P<0.001). The odds ratio for diabetes comparing participants in the highest vs. lowest tertile of African ancestry was 1.33 (95% confidence interval 1.13-1.55), after adjustment for age, sex, study, body mass index (BMI), and SES. Admixture scans identified two potential loci for diabetes at 12p13.31 (LOD = 4.0) and 13q14.3 (Z score = 4.5, P = 6.6×10-6). In conclusion, genetic ancestry has a significant association with type 2 diabetes above and beyond its association with non-genetic risk factors for type 2 diabetes in African Americans, but no single gene with a major effect is sufficient to explain a large portion of the observed population difference in risk of diabetes. There undoubtedly is a complex interplay among specific genetic loci and non-genetic factors, which may both be associated with overall admixture, leading to the observed ethnic differences in diabetes risk.
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Sitting Time and All-Cause Mortality Risk in 222 497 Australian Adults
Hidde van der Ploeg et al.
Archives of Internal Medicine, 26 March 2012, Pages 494-500
Background: Prolonged sitting is considered detrimental to health, but evidence regarding the independent relationship of total sitting time with all-cause mortality is limited. This study aimed to determine the independent relationship of sitting time with all-cause mortality.
Methods: We linked prospective questionnaire data from 222 497 individuals 45 years or older from the 45 and Up Study to mortality data from the New South Wales Registry of Births, Deaths, and Marriages (Australia) from February 1, 2006, through December 31, 2010. Cox proportional hazards models examined all-cause mortality in relation to sitting time, adjusting for potential confounders that included sex, age, education, urban/rural residence, physical activity, body mass index, smoking status, self-rated health, and disability.
Results: During 621 695 person-years of follow-up (mean follow-up, 2.8 years), 5405 deaths were registered. All-cause mortality hazard ratios were 1.02 (95% CI, 0.95-1.09), 1.15 (1.06-1.25), and 1.40 (1.27-1.55) for 4 to less than 8, 8 to less than 11, and 11 or more h/d of sitting, respectively, compared with less than 4 h/d, adjusting for physical activity and other confounders. The population-attributable fraction for sitting was 6.9%. The association between sitting and all-cause mortality appeared consistent across the sexes, age groups, body mass index categories, and physical activity levels and across healthy participants compared with participants with preexisting cardiovascular disease or diabetes mellitus.
Conclusions: Prolonged sitting is a risk factor for all-cause mortality, independent of physical activity. Public health programs should focus on reducing sitting time in addition to increasing physical activity levels.
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Black and White Body Mass Index Values in Nineteenth Century Developing Philadelphia County
Scott Alan Carson & Paul Hodges
Journal of Biosocial Science, May 2012, Pages 273-288
Abstract:
This paper demonstrates that although modern BMIs in the US have increased, 19th century BMIs in Philadelphia were lower than elsewhere within Pennsylvania, indicating that urbanization and agricultural commercialization were associated with lower BMIs. After controlling for stature, blacks consistently had greater BMI values than mulattos and whites; therefore, there is no evidence of a 19th century mulatto BMI advantage in the industrializing North. Farmers' BMIs were consistently heavier than those of non-farmers.
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Peter Hall
Health Psychology, March 2012, Pages 235-241
Objective: Fatty foods are regarded as highly appetitive, and self-control is often required to resist consumption. Executive control resources (ECRs) are potentially facilitative of self-control efforts, and therefore could predict success in the domain of dietary self-restraint. It is not currently known whether stronger ECRs facilitate resistance to fatty food consumption, and moreover, it is unknown whether such an effect would be stronger in some age groups than others. The purpose of the present study was to examine the association between ECRs and consumption of fatty foods among healthy community-dwelling adults across the adult life span.
Methods: An age-stratified sample of individuals between 18 and 89 years of age attended two laboratory sessions. During the first session they completed two computer-administered tests of ECRs (Stroop and Go-NoGo) and a test of general cognitive function (Wechsler Abbreviated Scale of Intelligence); participants completed two consecutive 1-week recall measures to assess frequency of fatty and nonfatty food consumption.
Results: Regression analyses revealed that stronger ECRs were associated with lower frequency of fatty food consumption over the 2-week interval. This association was observed for both measures of ECR and a composite measure. The effect remained significant after adjustment for demographic variables (age, gender, socioeconomic status), general cognitive function, and body mass index. The observed effect of ECRs on fatty food consumption frequency was invariant across age group, and did not generalize to nonfatty food consumption.
Conclusions: ECRs may be potentially important, though understudied, determinants of dietary behavior in adults across the life span.
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Bariatric Surgery versus Intensive Medical Therapy in Obese Patients with Diabetes
Philip Schauer et al.
New England Journal of Medicine, forthcoming
Background: Observational studies have shown improvement in patients with type 2 diabetes mellitus after bariatric surgery.
Methods: In this randomized, nonblinded, single-center trial, we evaluated the efficacy of intensive medical therapy alone versus medical therapy plus Roux-en-Y gastric bypass or sleeve gastrectomy in 150 obese patients with uncontrolled type 2 diabetes. The mean (±SD) age of the patients was 49±8 years, and 66% were women. The average glycated hemoglobin level was 9.2±1.5%. The primary end point was the proportion of patients with a glycated hemoglobin level of 6.0% or less 12 months after treatment.
Results: Of the 150 patients, 93% completed 12 months of follow-up. The proportion of patients with the primary end point was 12% (5 of 41 patients) in the medical-therapy group versus 42% (21 of 50 patients) in the gastric-bypass group (P=0.002) and 37% (18 of 49 patients) in the sleeve-gastrectomy group (P=0.008). Glycemic control improved in all three groups, with a mean glycated hemoglobin level of 7.5±1.8% in the medical-therapy group, 6.4±0.9% in the gastric-bypass group (P<0.001), and 6.6±1.0% in the sleeve-gastrectomy group (P=0.003). Weight loss was greater in the gastric-bypass group and sleeve-gastrectomy group (-29.4±9.0 kg and -25.1±8.5 kg, respectively) than in the medical-therapy group (-5.4±8.0 kg) (P<0.001 for both comparisons). The use of drugs to lower glucose, lipid, and blood-pressure levels decreased significantly after both surgical procedures but increased in patients receiving medical therapy only. The index for homeostasis model assessment of insulin resistance (HOMA-IR) improved significantly after bariatric surgery. Four patients underwent reoperation. There were no deaths or life-threatening complications.
Conclusions: In obese patients with uncontrolled type 2 diabetes, 12 months of medical therapy plus bariatric surgery achieved glycemic control in significantly more patients than medical therapy alone. Further study will be necessary to assess the durability of these results.
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Michael Roettger & Jason Boardman
American Journal of Epidemiology, 1 April 2012, Pages 636-644
Abstract:
Although recent studies suggest that 13% of young adults, including at least one-fourth of African Americans, experience parental incarceration, little research has examined links between parental incarceration and physical health. Using data from the National Longitudinal Study of Adolescent Health (1994-2008) and gender-based theories of stress, the authors examined whether parental incarceration is associated with increased body mass index among women but not men. Panel analysis spanning adolescence and adulthood, controlling for stressful life events, internalizing behaviors, and a range of individual, familial, and neighborhood characteristics, reveals that body mass index for women who have experienced parental incarceration is 0.49 units (P < 0.004) higher than that for women whose parents have never been incarcerated. This association is not evident among men. Similarly, in change score models between waves II and IV, women experiencing parental incarceration have a 0.92-unit increase in body mass index (P < 0.026) relative to women who did not have a parent undergo incarceration. In supplemental analysis examining if gender differences in incarceration stress response (externalizing vs. internalizing) explain these findings, the authors found that obesity status moderates the relation between depression and parental incarceration. Results suggest a stress internalization process that, for the first time, links parental incarceration with obesity among women.
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Few Associations between Income and Fruit and Vegetable Consumption
Amanda Middaugh et al.
Journal of Nutrition Education and Behavior, forthcoming
Objective: To examine the association between income and the consumption of fruits and vegetables using the poverty income ratio (PIR).
Design: Association between PIR and intake of fruits and vegetables combined. The PIR was divided into 5 groups ranging from < poverty threshold (PT) to ≥ 400% PT.
Participants: Adults aged 18 years and older (N = 16,232) who participated in the 1999-2006 National Health and Nutrition Examination Survey and fit the qualifiers.
Main Outcome Measures: The amount of combined fruit and vegetable intake based on income level.
Analyses: Using ANCOVA, a base model with increasing number of covariates was analyzed.
Results: Mean daily intake ranged from 253-324 g for those who consumed both fruits and vegetables (N = 16,213). In the base model, significant differences in intake occurred between those who were at ≥ 400% PT and PIR groups < 400. When age, sex, race/ethnicity, and calorie intake were added to the base model, these differences remained. Adding educational level to the model removed these differences.
Conclusions and Implications: Dietary intake of fruits and vegetables is directly related to income when income reaches levels of ≥ 400% PT. These differences are mediated by education. Providing nutrition education may help individuals to reach the recommended level of consumption of fruits and vegetables.
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Paul Williams
PLoS ONE, February 2012
Objective: Physical activity has been shown to attenuate the effect of the FTO polymorphism on body weight, and the heritability of body weight in twin and in family studies. The dose-response relationship between activity and the risk for inherited obesity is not well known, particularly for higher doses of vigorous exercise. Such information is needed to best prescribe an exercise dose for obesity prevention in those at risk due to their family history.
Design: We therefore analyzed self-reported usual running distance, body mass index (BMI), waist circumference, and mother's and father's adiposity (1 = lean, 2 = normal, 3 = overweight, and 4 = very overweight) from survey data collected on 33,480 male and 14,211 female runners. Age-, education-, and alcohol-adjusted regression analyses were used to estimate the contribution of parental adiposities to the BMI and waist circumferences in runners who ran an average of <3, 3-6, 6-9, ≥9 km/day.
Results: BMI and waist circumferences of runners who ran <3 km/day were significantly related to their parents adiposity (P<10-15 and P<10-11, respectively). These relationships (i.e., kg/m2 or cm per increment in parental adiposity) diminished significantly with increasing running distance for both BMI (inheritance×exercise interaction, males: P<10-10; females: P<10-5) and waist circumference (inheritance × exercise interaction, males: P<10-9; females: P = 0.004). Compared to <3 km/day, the parental contribution to runners who averaged ≥9 km/day was diminished by 48% for male BMI, 58% for female BMI, 55% for male waist circumference, and 58% for female waist circumference. These results could not be attributed to self-selection.
Conclusions: Exceeding the minimum exercise dose currently recommended for general health benefits (energy equivalent to running 2-3 km/day) may substantially diminish the risk for inherited obesity. The results are consistent with other research suggesting the physical activity dose required to prevent unhealthy weight gain is greater than that recommended for other health benefits.
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Rebecca Hasson et al.
Obesity, April 2012, Pages 811-818
Abstract:
The purpose of this study was to examine ethnic differences in the metabolic responses to a 16-week intervention designed to improve insulin sensitivity (SI), adiposity, and inflammation in obese African-American and Latino adolescents. A total of 100 participants (African Americans: n = 48, Latino: n = 52; age: 15.4 ± 1.1 years, BMI percentile: 97.3 ± 3.3) were randomly assigned to interventions: control (C; n = 30), nutrition (N; n = 39, 1×/week focused on decreasing sugar and increasing fiber intake), or nutrition + strength training (N+ST; n = 31, 2×/week). The following were measured at pre- and postintervention: strength, dietary intake, body composition (dual-energy X-ray absorptiometry/magnetic resonance imaging) and glucose/insulin indexes (oral glucose tolerance test (OGTT)/intravenous glucose tolerance test (IVGTT)) and inflammatory markers. Overall, N compared to C and N+ST reported significant improvements in SI (+16.5% vs. -32.3% vs. -6.9% respectively, P < 0.01) and disposition index (DI: +15.5% vs. -14.2% vs. -13.7% respectively, P < 0.01). N+ST compared to C and N reported significant reductions in hepatic fat fraction (HFF: -27.3% vs. -4.3% vs. 0% respectively, P < 0.01). Compared to N, N+ST reported reductions in plasminogen activator inhibitor-1 (PAI-1) (-38.3% vs. +1.0%, P < 0.01) and resistin (-18.7% vs. +11.3%, P = 0.02). There were no intervention effects for all other measures of adiposity or inflammation. Significant intervention by ethnicity interactions were found for African Americans in the N group who reported increases in total fat mass, 2-h glucose and glucose incremental areas under the curve (IAUC) compared to Latinos (P's < 0.05). These interventions yielded differential effects with N reporting favorable improvements in SI and DI and N+ST reporting marked reductions in HFF and inflammation. Both ethnic groups had significant improvements in metabolic health; however some improvements were not seen in African Americans.
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Ross Whitehead et al.
PLoS ONE, March 2012
Background: Fruit and vegetable consumption and ingestion of carotenoids have been found to be associated with human skin-color (yellowness) in a recent cross-sectional study. This carotenoid-based coloration contributes beneficially to the appearance of health in humans and is held to be a sexually selected cue of condition in other species.
Methodology and Principal Findings: Here we investigate the effects of fruit and vegetable consumption on skin-color longitudinally to determine the magnitude and duration of diet change required to change skin-color perceptibly. Diet and skin-color were recorded at baseline and after three and six weeks, in a group of 35 individuals who were without makeup, self-tanning agents and/or recent intensive UV exposure. Six-week changes in fruit and vegetable consumption were significantly correlated with changes in skin redness and yellowness over this period, and diet-linked skin reflectance changes were significantly associated with the spectral absorption of carotenoids and not melanin. We also used psychophysical methods to investigate the minimum color change required to confer perceptibly healthier and more attractive skin-coloration. Modest dietary changes are required to enhance apparent health (2.91 portions per day) and attractiveness (3.30 portions).
Conclusions: Increased fruit and vegetable consumption confers measurable and perceptibly beneficial effects on Caucasian skin appearance within six weeks. This effect could potentially be used as a motivational tool in dietary intervention.
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Dietary fat and semen quality among men attending a fertility clinic
Jill Attaman et al.
Human Reproduction, forthcoming
Background: The objective of this study was to examine the relation between dietary fats and semen quality parameters.
Methods: Data from 99 men with complete dietary and semen quality data were analyzed. Fatty acid levels in sperm and seminal plasma were measured using gas chromatography in a subgroup of men (n = 23). Linear regression was used to determine associations while adjusting for potential confounders.
Results: Men were primarily Caucasian (89%) with a mean (SD) age of 36.4 (5.3) years; 71% were overweight or obese; and 67% were never smokers. Higher total fat intake was negatively related to total sperm count and concentration. Men in the highest third of total fat intake had 43% (95% confidence interval (CI): 62-14%) lower total sperm count and 38% (95% CI: 58-10%) lower sperm concentration than men in the lowest third (Ptrend = 0.01). This association was driven by intake of saturated fats. Levels of saturated fatty acids in sperm were also negatively related to sperm concentration (r= -0.53), but saturated fat intake was unrelated to sperm levels (r = 0.09). Higher intake of omega-3 polyunsaturated fats was related to a more favorable sperm morphology. Men in the highest third of omega-3 fatty acids had 1.9% (0.4-3.5%) higher normal morphology than men in the lowest third (Ptrend = 0.02).
Conclusions: In this preliminary cross-sectional study, high intake of saturated fats was negatively related to sperm concentration whereas higher intake of omega-3 fats was positively related to sperm morphology. Further, studies with larger samples are now required to confirm these findings.