Feedlot
What Money Can Buy: Family Income and Childhood Obesity
Young Jo
Economics & Human Biology, December 2014, Pages 1–12
Abstract:
This paper investigates the relationship between family income and childhood obesity. Using the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K), I report three new findings. First, family income and childhood obesity are generally negatively correlated, but for children in very low-income families, they are positively correlated. Second, the negative association between family income and Body Mass Index (BMI) is especially strong and significant among high-BMI children. Third, the difference in obesity rates between children from low- and high-income families increases as children age. This study further investigates potential factors that might contribute to a rapid increase in the obesity rate among low-income children. I find that their faster weight gain, rather than slower height growth, is a greater contributor to the rapid increase in their BMI over time. On the other hand, I also find that the faster weight gain by low-income children cannot be attributed to any single factor, such as participation in school meal programs, parental characteristics, or individual characteristics. These findings add to the current obesity debate by demonstrating that the key to curbing childhood obesity may lie in factors generating different obesity rates across income levels.
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Neighborhood Effects on Food Consumption
Tammy Leonard et al.
Journal of Behavioral and Experimental Economics, August 2014, Pages 99–113
Abstract:
Food consumption behavior is likely a result of environmental stimuli, access, and personal preferences, making policy aimed at increasing the nutritional content of food consumption challenging. We examine the dual role of the social and physical neighborhood environment as they relate to the eating behaviors of residents of a low-income minority urban neighborhood. We find that both proximity to different types of food sources (a characteristic of the physical neighborhood environment) and dietary intake of neighbors (a characteristic of the neighborhood's social environment) are related to dietary intake. The relationships are most robust for fruits and vegetables consumption. Proximity to fast food sources is related to less fruits and vegetables consumption while the opposite is found for individuals residing closer to fresh food sources. Additionally, individuals whose neighbors report increased fruits and vegetables intake also report higher fruits and vegetables consumption, while controlling for proximity to food sources. Instrumental variable and quasi-experimental robustness checks suggest that correlation in neighbors’ fruits and vegetables consumption is likely due to social interactions among neighboring residents. The results elucidate important inter-relationships between access and social norms that influence dietary behavior.
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John List & Anya Savikhin Samek
NBER Working Paper, May 2014
Abstract:
Childhood obesity has reached epidemic proportions in the U.S., with now almost a third of children ages 2-19 deemed overweight or obese. In this study, we leverage recent findings from behavioral economics to explore new approaches to tackling one aspect of childhood obesity: food choice and consumption. Using a field experiment where we include more than 1,500 children, we report several key insights. First, we find that individual incentives can have large influences: in the control, only 17% of children prefer the healthy snack, whereas the introduction of small incentives increases take-up of the healthy snack to roughly 75%, more than a four-fold increase. There is some evidence that the effects continue after the treatment period, consistent with a model of habit formation. Second, we find little evidence that the framing of incentives (loss versus gain) matters. While incentives work, we find that educational messaging alone has little influence on food choice. Yet, we do observe an important interaction effect between messaging and incentives: together they provide an important influence on food choice. For policymakers, our findings show the power of using incentives to combat childhood obesity. For academics, our approach opens up an interesting combination of theory and experiment that can lead to a better understanding of theories that explain healthy decisions and what incentives can influence them.
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Differences by mother’s education in the effect of childcare on child obesity
Zafar Nazarov & Michael Rendall
Economics Letters, forthcoming
Abstract:
Previous studies have found adverse effects of maternal employment on child obesity for higher educated mothers. Using a quasi-structural model, we find additionally a lower risk of obesity for children of less educated mothers with increased time in non-parental childcare.
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Emily McFadden et al.
American Journal of Epidemiology, forthcoming
Abstract:
There has been a worldwide epidemic of obesity in recent decades. In animal studies, there is convincing evidence that light exposure causes weight gain, even when calorie intake and physical activity are held constant. Disruption of sleep and circadian rhythms by exposure to light at night (LAN) might be one mechanism contributing to the rise in obesity, but it has not been well-investigated in humans. Using multinomial logistic regression, we examined the association between exposure to LAN and obesity in questionnaire data from over 100,000 women in the Breakthrough Generations Study, a cohort study of women aged 16 years or older who were living in the United Kingdom and recruited during 2003–2012. The odds of obesity, measured using body mass index, waist:hip ratio, waist:height ratio, and waist circumference, increased with increasing levels of LAN exposure (P < 0.001), even after adjustment for potential confounders such as sleep duration, alcohol intake, physical activity, and current smoking. We found a significant association between LAN exposure and obesity which was not explained by potential confounders we could measure. While the possibility of residual confounding cannot be excluded, the pattern is intriguing, accords with the results of animal experiments, and warrants further investigation.
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Adam Fletcher et al.
Sociology, June 2014, Pages 500-517
Abstract:
Drawing on two qualitative studies, we report evidence of pervasive black markets in confectionery, ‘junk’ food and energy drinks in English secondary schools. Data were collected at six schools through focus groups and interviews with students (n = 149) and staff (n = 36), and direct observations. Supermarkets, new technologies and teachers’ narrow focus on attainment have enabled these ‘underground businesses’ to emerge following increased state regulation of school food and drink provision. These activities represent a new form of counter-school resistance to institutional constraints within the context of enduring, although less visible, class-based stratification in British secondary schools. These black markets also appear to be partly driven by the unsafe and unsociable nature of school canteens, which was a recurring theme across all schools. These findings highlight how new school food ‘bans’ ignore the complex, ecological drivers of poor diet in youth and the potential for iatrogenic effects which exacerbate health inequalities.
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If It's Useful and You Know It, Do You Eat? Preschoolers Refrain from Instrumental Food
Michal Maimaran & Ayelet Fishbach
Journal of Consumer Research, forthcoming
Abstract:
Marketers, educators, and caregivers often refer to instrumental benefits to convince preschoolers to eat (e.g., “this food will make you strong”). We propose that preschoolers infer that if food is instrumental to achieve a goal, it is less tasty, and therefore they consume less of it. Accordingly, preschoolers (3-5.5 years old) rated crackers as less tasty and consumed fewer of them when the crackers were presented as instrumental to achieve a health goal (studies 1-2). In addition, preschoolers consumed fewer carrots and crackers when these were presented as instrumental to knowing how to read (study 3) and count (studies 4-5). This research supports an inference account for the negative impact of certain persuasive messages on consumption: preschoolers who are exposed to one association (e.g., between eating carrots and intellectual performance) infer another association (e.g., between carrots and taste) must be weaker.
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Esra Tasali et al.
Appetite, September 2014, Pages 220–224
Introduction: Sleep curtailment is an endemic behavior in modern society. Well-controlled laboratory studies have shown that sleep loss in young adults is associated with increased desire for high-calorie food and obesity risk. However, the relevance of these laboratory findings to real life is uncertain. We conducted a 3 week, within-participant, intervention study to assess the effects of extended bedtimes on sleep duration and food desire under real life conditions in individuals who are at risk for obesity.
Methods: Ten overweight young adults reporting average habitual sleep duration of less than 6.5 h were studied in the home environment. Habitual bedtimes for 1-week (baseline) were followed by bedtimes extended to 8.5 h for 2-weeks (intervention). Participants were unaware of the intervention until after the baseline period. Participants received individualized behavioral counseling on sleep hygiene on the first day of the intervention period. Sleep duration was recorded by wrist actigraphy throughout the study. Participants rated their sleepiness, vigor and desire for various foods using visual analog scales at the end of baseline and intervention periods.
Results: On average, participants obtained 1.6 h more sleep with extended bedtimes (5.6 vs 7.1; P < 0.001) and reported being less sleepy (P = 0.004) and more vigorous (P = 0.034). Additional sleep was associated with a 14% decrease in overall appetite (P = 0.030) and a 62% decrease in desire for sweet and salty foods (P = 0.017). Desire for fruits, vegetables and protein-rich nutrients was not affected by added sleep.
Conclusions: Sleep duration can be successfully increased in real life settings and obtaining adequate sleep is associated with less desire for high calorie foods in overweight young adults who habitually curtail their sleep.
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The Short-Run Impact of the Healthy Incentives Pilot Program on Fruit and Vegetable Intake
Jacob Klerman et al.
American Journal of Agricultural Economics, forthcoming
Abstract:
In response to low consumption levels of fruits and vegetables by Supplemental Nutrition Assistance Program (SNAP) participants, the USDA Food and Nutrition Service created the Healthy Incentives Pilot (HIP) to test the efficacy of providing a 30% incentive for purchases of targeted fruits and vegetables (TFVs). Four to six months after implementation, mean daily TFV intake for adult HIP participants was 0.22 cup-equivalents higher (24% higher) than for control-group SNAP participants. These impact estimates with a random-assignment research design generally agree with previously published nonexperimental elasticity estimates, which imply that a pure price reduction of 30% would increase fruit and vegetable consumption by about 20%.
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The Effects of Taxing Sugar-Sweetened Beverages across Different Income Groups
Anurag Sharma et al.
Health Economics, forthcoming
Abstract:
This paper investigates the impact of sugar-sweetened beverages (SSB) taxes on consumption, bodyweight and tax burden for low-income, middle-income and high-income groups using an Almost Ideal Demand System and 2011 Household level scanner data. A significant contribution of our paper is that we compare two types of SSB taxes recently advocated by policy makers: A 20% flat rate sales (valoric) tax and a 20 cent/L volumetric tax. Censored demand is accounted for using a two-step procedure. We find that the volumetric tax would result in a greater per capita weight loss than the valoric tax (0.41 kg vs. 0.29 kg). The difference between the change in weight is substantial for the target group of heavy purchasers of SSBs in low-income households, with a weight reduction of up to 3.20 kg for the volumetric and 2.06 kg for the valoric tax. The average yearly per capita tax burden on low-income households is $17.87 (0.21% of income) compared with $15.17 for high-income households (0.07% of income) for the valoric tax, and $13.80 (0.15%) and $10.10 (0.04%) for the volumetric tax. Thus, the tax burden is lower, and weight reduction is higher under a volumetric tax.
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Obesity and the Natural Environment Across US Counties
Paul von Hippel & Rebecca Benson
American Journal of Public Health, July 2014, Pages 1287-1293
Objectives: We estimated the association between obesity and features of the natural environment. We asked whether the association is mediated by diet or by physical activity.
Methods: Using county-level data from the contiguous United States, we regressed adult obesity prevalence on 9 measures of the natural environment. Our regression model accounted for spatial correlation, and controlled for county demographics and the built environment. We included physical activity and diet (proxied by food purchases) as potential mediators.
Results: Obesity was more prevalent in counties that are hot in July or cold in January. To a lesser degree, obesity was more prevalent in counties that are dark in January or rainy (but not snowy) year-round. Other aspects of the natural environment—including wind, trees, waterfront, and hills and mountains—had little or no association with obesity. Nearly all of the association between obesity and the natural environment was mediated by physical activity; none was mediated by diet.
Conclusions: Hot summers and cold winters appear to promote obesity by discouraging physical activity. Attempts to encourage physical activity should compensate for the effects of extreme temperatures.
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Maternal prepregnancy obesity and child neurodevelopment in the Collaborative Perinatal Project
Lisu Huang et al.
International Journal of Epidemiology, June 2014, Pages 783-792
Objectives: To examine the association between maternal prepregnancy weight and child neurodevelopment, and the effect of gestational weight gain.
Methods: Using the U.S. Collaborative Perinatal Project data, 1959–76, a total of 30 212 women with a calculable prepregnancy body mass index (BMI) and gestational weight gain, and term singleton children followed up for more than 7 years were included in this study. Intelligence quotient (IQ) was measured at 7 years of age by Wechsler Intelligence Scales.
Results: Maternal prepregnancy BMI displayed inverted U-shaped associations with child IQ after adjustment for maternal age, maternal education levels, maternal race, marital status, socioeconomic status, smoking during pregnancy, parity and study center. Women with BMI at around 20 kg/m2 appeared to have the highest offspring IQ scores. After controlling for familial factors in the siblings’ sample, maternal obesity (BMI ≥30.0 kg/m2) was associated with lower Full-scale IQ (adjusted ß = −2.0, 95% confidence interval −3.5 to −0.5), and Verbal scale IQ (adjusted ß = −2.5, 95% confidence interval −4.0 to −1.0), using BMI of 18.5–24.9 kg/m2 as the reference category. Compared with children born to normal-weight women who gained 21–25 lb. during pregnancy, those born to obese women who gained more than 40 lb. had 6.5 points deficit in IQ after adjustment for potential confounders.
Conclusions: Maternal prepregnancy obesity was associated with lower child IQ, and excessive weight gain accelerated the association. With obesity rising steadily, these results appear to raise serious public health concerns.
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Luis Rivera & Stefanie Paredez
Journal of Social Issues, June 2014, Pages 226–240
Abstract:
The authors draw upon social, personality, and health psychology to propose and test a self-stereotyping and psychological resource model of overweight and obesity. The model contends that self-stereotyping depletes psychological resources, namely self-esteem, that help to prevent overweight and obesity. In support of the model, mediation analysis demonstrates that adult Hispanics who highly self-stereotype had lower levels of self-esteem than those who self-stereotype less, which in turn predicted higher levels of body mass index (overweight and obesity levels). Furthermore, the model did not hold for the referent sample, White participants, and an alternative mediation model was not supported. These data are the first to theoretically and empirically link self-stereotyping and self-esteem (a psychological resource) with a strong physiological risk factor for morbidity and short life expectancy in stigmatized individuals. Thus, this research contributes to understanding ethnic-racial health disparities in the United States and beyond.
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Is there an influence of modern life style on skeletal build?
Christiane Scheffler & Michael Hermanussen
American Journal of Human Biology, forthcoming
Objectives: Modern human life style has led to significant decrease in everyday physical activity and bipedal locomotion. It has previously been shown that skeletal robustness (relative elbow breadth) is associated with daily step counts. The aim of the study was to investigate whether also other skeletal measures, particularly pelvic breadth may have changed in recent decades.
Methods: We re-analyzed elbow breadth, pelvic breadth (bicristal), and thoracic depth and breadth, of up to 28,975 healthy females and 28,288 healthy males aged 3–18 years from cross-sectional anthropological surveys performed between 1980 and 2012 by the Universities of Potsdam and Berlin, Germany.
Results: Relative elbow breadth (Frame index) significantly decreased in both sexes since 1980 (<0.001). The trend toward slighter built was even more pronounced in absolute and relative pelvic breadth. In contrast, equivalent changes of parts of the skeletal system that are not involved in bipedal locomotion such as thoracic breadth, thoracic depth, and the thoracic index were absent.
Conclusions: The present investigation confirms the decline in relative elbow breadth in recent decades. Analogue, but even more pronounced changes were detected in pelvic breadth that coincides with the modern decline in upright locomotion. The findings underscore the phenotypic plasticity of humans while adapting to new environmental conditions.
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The effect of portion size on food intake is robust to brief education and mindfulness exercises
Karen Cavanagh et al.
Journal of Health Psychology, June 2014, Pages 730-739
Abstract:
We examined whether a brief education and a brief mindfulness exercise would reduce the effect of portion size on food intake. Participants were randomly assigned to one of the three information conditions (education, mindfulness, or control) and then received a small or large portion of pasta for lunch. Neither education nor mindfulness was effective in reducing the effect of portion size: Overall, participants served a large portion consumed 34 percent more pasta than did those served a small portion. Participants in the mindfulness condition tended to eat less overall than participants did in the two other conditions, but this trend was not significant.
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Sandra Albrecht & Penny Gordon-Larsen
Journal of Epidemiology & Community Health, forthcoming
Background: Despite comparatively lower socioeconomic status (SES), immigrants tend to have lower body weight and weaker SES gradients relative to US-born individuals. Yet, it is unknown how changes in SES over the life-course relate to body weight in immigrants versus US-born individuals.
Methods: We used longitudinal data from a nationally representative, diverse sample of 13 701 adolescents followed into adulthood to investigate whether associations between SES mobility categories (educational attainment reported by individuals as adults and by their parents during adolescence) and body mass index (BMI) measured in adulthood varied by immigrant generation. Weighted multivariable linear regression models were adjusted for age, sex, race/ethnicity and immigrant generation.
Results: Among first-generation immigrants, although parental education was not associated with adult BMI, an immigrant's own education attainment was inversely associated with BMI (β=−2.6 kg/m2; SE=0.9, p<0.01). In addition, upward educational mobility was associated with lower adult mean BMI than remaining low SES (β=−2.5 kg/m2; SE=1.2, p<0.05). In contrast, among US-born respondents, college education in adulthood did not attenuate the negative association between parental education and adult BMI. Although an SES gradient emerged in adulthood for immigrants, remaining low SES from adolescence to adulthood was not associated with loss of health advantage relative to US-born respondents of US-born parents of similar SES.
Conclusions: Immigrants were able to translate higher SES in adulthood into a lower adult mean BMI regardless of childhood SES, whereas the consequences of lower childhood SES had a longer reach even among the upwardly mobile US born.
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Individual differences in executive function predict distinct eating behaviours
Vanessa Allom & Barbara Mullan
Appetite, September 2014, Pages 123–130
Abstract:
Executive function has been shown to influence the performance of health behaviours. Healthy eating involves both the inhibitory behaviour of consuming low amounts of saturated fat, and the initiatory behaviour of consuming fruit and vegetables. Based on this distinction, it was hypothesised that these behaviours would have different determinants. Measures of inhibitory control and updating were administered to 115 participants across 2 days. One week later saturated fat intake and fruit and vegetable consumption were measured. Regression analyses revealed a double dissociation effect between the different executive function variables and the prediction of eating behaviours. Specifically, inhibitory control, but not updating, predict saturated fat intake, whilst updating, but not inhibitory control, was related to fruit and vegetable consumption. In both cases, better executive function capacity was associated with healthier eating behaviour. The results support the idea that behaviours that require stopping a response such as limiting saturated fat intake, have different determinants to those that require the initiation of a response such as fruit and vegetable consumption. The findings suggest that interventions aimed at improving these behaviours should address the relevant facet of executive function.