Something to chew on
Maoyong Fan & Yanhong Jin
American Journal of Health Economics, forthcoming
Abstract:
Using the National Longitudinal Survey of Youth 1997, this paper employs difference-in-difference propensity score matching to examine whether the Supplementary Nutrition Assistance Program (SNAP) contributes to childhood obesity. We find no statistically significant SNAP effect among the 12- to 20-year-old participants when controlling for selection bias and more accurately defining the treatment and comparison groups. The results are robust to various robustness checks including redefining the treatment and comparison groups by excluding those who previously enrolled in the SNAP, using an alternative treatment definition based on SNAP benefits received, using different specifications of the propensity score equation, and employing different estimation techniques (covariate matching and inverse probability weighting). This study differs from previous research in the three major aspects. First, we carefully examine the intensity of SNAP participation (full-time vs. part-time) and the amount of SNAP benefits received for one-, two-, and three-year durations. Second, we focus on the change in the BMI or the obesity status rather than the level and control for the pre-treatment BMI to avoid the confounding effects of the time-invariant factors. Third, instead of making parametric assumptions on the outcomes, we employ a variety of semi-parametric estimators to control for the selection bias of program participation. The results show that the SNAP is not responsible for the higher prevalence of obesity among adolescents of low-income households. Proposed SNAP changes such as more frequent benefit distribution and a focus on fresh fruits and vegetables are likely to be ineffective in reducing childhood obesity, although they might encourage healthy dietary practices among SNAP participants.
---------------------
A Prospective Study of Fitness, Fatness, and Depressive Symptoms
Katie Becofsky et al.
American Journal of Epidemiology, 1 March 2015, Pages 311-320
Abstract:
Being overweight or obese might be a risk factor for developing depression. It is also possible that low cardiorespiratory fitness, rather than overweight or obesity, is the better predictor of depressive symptom onset. Adults in the Aerobics Center Longitudinal Study (Dallas, Texas) underwent fitness and fatness assessments between 1979 and 1998 and later completed a questionnaire about depressive symptoms in 1990, 1995, or 1999. Separate logistic regression models were used to test the associations between 3 fatness measures (body mass index, waist circumference, and percentage of body fat) and the onset of depressive symptoms. Analyses were repeated using fitness as the predictor variable. Additional analyses were performed to study the joint association of fatness and fitness with the onset of depressive symptoms. After controlling for fitness, no measure of fatness was associated with the onset of depressive symptoms. In joint analyses, low fitness was more strongly associated with the onset of elevated depressive symptoms than was fatness, regardless of the measure of fatness used. Overall, results from the present study suggest that low fitness is more strongly associated with the onset of elevated depressive symptoms than is fatness. To reduce the risk of developing depression, individuals should be encouraged to improve their fitness regardless of body fatness.
---------------------
Can Changing Economic Factors Explain the Rise in Obesity?
Charles Courtemanche et al.
NBER Working Paper, January 2015
Abstract:
A growing literature examines the effects of economic variables on obesity, typically focusing on only one or a few factors at a time. We build a more comprehensive economic model of body weight, combining the 1990-2010 Behavioral Risk Factor Surveillance System with 27 state-level variables related to general economic conditions, labor supply, and the monetary or time costs of calorie intake, physical activity, and cigarette smoking. Controlling for demographic characteristics and state and year fixed effects, changes in these economic variables collectively explain 37% of the rise in BMI, 43% of the rise in obesity, and 59% of the rise in class II/III obesity. Quantile regressions also point to large effects among the heaviest individuals, with half the rise in the 90th percentile of BMI explained by economic factors. Variables related to calorie intake – particularly restaurant and supercenter/warehouse club densities – are the primary drivers of the results.
---------------------
Michael Marlow
Applied Economics Letters, forthcoming
Abstract:
This article examines whether obesity prevalence is influenced by the market structure of retail food outlets. A few studies have examined the effects of ‘big box’ stores on prices, food choices and obesity, but the present study extends empirical examination to all types of stores to determine if there are significant differences in their effects on obesity prevalence. Four types of retail food outlets are examined: supermarkets, supercentres and warehouse club stores (i.e. ‘big box’ stores), convenience stores and specialty stores. Counties with more retail food stores experience lower prevalence of adult obesity, but this inverse relationship appears to stem from greater numbers of supermarkets and specialty food stores. Obesity prevalence is positively associated with market shares of ‘big box’ and convenience stores.
---------------------
Body Weight Misperception in Adolescence and Incident Obesity in Young Adulthood
Angelina Sutin & Antonio Terracciano
Psychological Science, forthcoming
Abstract:
Misperceptions of one’s weight are common in adolescence. Adolescents of normal weight who misperceive themselves as being overweight tend to engage in unhealthy dieting practices and behaviors that are conducive to obesity. To examine whether this misperception is associated with a risk of obesity during early adulthood, we analyzed data from the National Longitudinal Study of Adolescent Health (N = 6,523; mean age at baseline = 16 years; 58% female). Adolescents who misperceived themselves as being overweight had a 40% greater risk of becoming obese over the 12-year follow-up period than adolescents who perceived their weight accurately (odds ratio = 1.41, 95% confidence interval = [1.22, 1.64]). Although the risk associated with misperception of weight was apparent for both sexes, it was significantly stronger among boys (89% higher risk) than among girls (29% higher risk). The present research indicates that weight-based self-stigmatization, much like weight-based social stigmatization, is a powerful risk factor for incident obesity. This finding underscores the importance of addressing inaccurate body weight perceptions, even among adolescents of normal weight.
---------------------
Miao Li
American Journal of Epidemiology, forthcoming
Abstract:
In this study, I used the growth curve model to examine the association between grandparents' (first generation (G1)) life-course exposure to chronic poverty and grandchildren's (third generation (G3)) body mass index (BMI; weight (kg)/height (m)2) growth trajectories. This association was estimated separately for male and female grandchildren. Analyses were based on prospective data from a US longitudinal survey, the Panel Study of Income Dynamics (1968–2011), and 2 of its supplemental studies: the Child Development Supplement (1997–2011) and the Transition into Adulthood Study (1997–2011). A prospectively enrolled nationally representative cohort of 2,613 G3 youth (1,323 male, 1,290 female) sampled in the 2 supplemental studies was linked to 1,719 grandparents from the Panel Study of Income Dynamics core sample. Chronic exposure to poverty among grandparents was prospectively ascertained annually over a 30-year period prior to the collection of data on grandchildren. Findings suggested that grandparents' chronic poverty exposure was positively associated with the slope of the BMI trajectory among granddaughters (β = 0.10, 95% confidence interval: 0.03, 0.17) but not among grandsons (β = 0.02, 95% confidence interval: −0.04, 0.08). The association between grandparents' chronic poverty exposure and granddaughters' BMI growth slope remained even after controlling for parental (second generation (G2)) socioeconomic status and BMI.
---------------------
Sugar-sweetened beverage consumption and age at menarche in a prospective study of US girls
J.L Carwile et al.
Human Reproduction, March 2015, Pages 675-683
Study design, size, duration: The Growing up Today Study, a prospective cohort study of 16 875 children of Nurses' Health Study II participants residing in all 50 US states. This analysis followed 5583 girls, aged 9–14 years and premenarcheal at baseline, between 1996 and 2001. During 10 555 person-years of follow-up, 94% (n = 5227) of girls reported their age at menarche, and 3% (n = 159) remained premenarcheal in 2001; 4% (n = 197) of eligible girls were censored, primarily for missing age at menarche.
Participants/materials, setting, methods: Cumulative updated SSB consumption (composed of non-carbonated fruit drinks, sugar-sweetened soda and iced tea) was calculated using annual Youth/Adolescent Food Frequency Questionnaires from 1996 to 1998. Age at menarche was self-reported annually. The association between SSB consumption and age at menarche was assessed using Cox proportional hazards regression.
Main results and the role of chance: More frequent SSB consumption predicted earlier menarche. At any given age between 9 and 18.5 years, premenarcheal girls who reported consuming >1.5 servings of SSBs per day were, on average, 24% more likely [95% confidence interval (CI): 13, 36%; P-trend: <0.001] to attain menarche in the next month relative to girls consuming ≤2 servings of SSBs weekly, adjusting for potential confounders including height, but not BMI (considered an intermediate). Correspondingly, girls consuming >1.5 SSBs daily had an estimated 2.7-month earlier menarche (95% CI: −4.1, −1.3 months) relative to those consuming ≤2 SSBs weekly. The frequency of non-carbonated fruit drink (P-trend: 0.03) and sugar-sweetened soda (P-trend: 0.001), but not iced tea (P-trend: 0.49), consumption also predicted earlier menarche. The effect of SSB consumption on age at menarche was observed in every tertile of baseline BMI. Diet soda and fruit juice consumption were not associated with age at menarche.
Wider implications of the findings: More frequent SSB consumption may predict earlier menarche through mechanisms other than increased BMI. Our findings provide further support for public health efforts to reduce SSB consumption.
---------------------
The Effects of Prospective Mate Quality on Investments in Healthy Body Weight Among Single Women
Matthew Harris & Christopher Cronin
University of Tennessee Working Paper, October 2014
Abstract:
This paper examines how a single female's investment in healthy body weight is affected by the quality of single males in her marriage market. A principle concern in estimation is the presence of market-level unobserved heterogeneity that may be correlated with changes in single male quality. To address this concern, we employ a differencing strategy that normalizes the exercise behaviors of single women to those of their married counterparts. Our main results suggest that when potential mate quality in a marriage market decreases, single black women invest less in healthy body weight. For example, we find that a ten percentage point increase in the proportion of low quality single black males leads to a 5% to 10% decrease in vigorous exercise taken by single black females. No significant response is found for single white women. These results highlight the relationship between male and female human capital acquisition that is driven by participation in the marriage market. Our results suggest that programs designed to improve the economic prospects of single males may yield positive externalities in the form of improved health behaviors, such as more exercise, particularly for single black females.
---------------------
An experimental field study of weight salience and food choice
Angela Incollingo Rodriguez et al.
Appetite, forthcoming
Abstract:
Laboratory research has found that individuals will consume more calories and make unhealthy food choices when in the presence of an overweight individual, sometimes even regardless of what that individual is eating. This study expanded these laboratory paradigms to the field to examine how weight salience influences eating in the real world. More specifically, we tested the threshold of the effect of weight salience of food choice to see if a more subtle weight cue (e.g., images) would be sufficient to affect food choice. Attendees (N = 262) at Obesity Week 2013, a weight-salient environment, viewed slideshows containing an image of an overweight individual, an image of a thin individual, or no image (text only), and then selected from complimentary snacks. Results of ordinal logistic regression analysis showed that participants who viewed the image of the overweight individual had higher odds of selecting the higher calorie snack compared to those who viewed the image of the thin individual (OR = 1.77, 95% CI = [1.04, 3.04]), or no image (OR = 2.42, 95% CI = [1.29, 4.54]). Perceiver BMI category did not moderate the influence of image on food choice, as these results occurred regardless of participant BMI. These findings suggest that in the context of societal weight salience, weight-related cues alone may promote unhealthy eating in the general public.
---------------------
The Role of Physicians in Promoting Weight Loss
Joshua Berning
Economics & Human Biology, forthcoming
Abstract:
There are numerous costs resulting from being overweight or obese. A relevant question is how to effectively reduce rates of obesity. I examine the effect of advice from a physician or heath care provider to lose weight on individual weight outcomes using survey data. I account for selection bias using a control function approach and rely on data restrictions to control for simultaneity. I find robust results indicating that advice has a significant effect on weight loss. Several studies suggest physicians may not adequately advise their patients about weight loss. The results of this paper highlight an important opportunity for physicians to advise at-risk patients.
---------------------
Does providing nutrition information at vending machines reduce calories per item sold?
Deirdre Dingman et al.
Journal of Public Health Policy, February 2015, Pages 110–122
Abstract:
In 2010, the United States (US) enacted a restaurant menu labeling law. The law also applied to vending machine companies selling food. Research suggested that providing nutrition information on menus in restaurants might reduce the number of calories purchased. We tested the effect of providing nutrition information and ‘healthy’ designations to consumers where vending machines were located in college residence halls. We conducted our study at one university in Southeast US (October–November 2012). We randomly assigned 18 vending machines locations (residence halls) to an intervention or control group. For the intervention we posted nutrition information, interpretive signage, and sent a promotional email to residents of the hall. For the control group we did nothing. We tracked sales over 4 weeks before and 4 weeks after we introduced the intervention. Our intervention did not change what the residents bought. We recommend additional research about providing nutrition information where vending machines are located, including testing formats used to present information.
---------------------
Trends in overweight and obesity in soldiers entering the US Army, 1989-2012
Adela Hruby et al.
Obesity, March 2015, Pages 662–670
Objective: The US Army recruits new soldiers from an increasingly obese civilian population. The change in weight status at entry into the Army between 1989 and 2012 and the demographic characteristics associated with overweight/obesity at entry were examined.
Methods: 1,741,070 unique individuals with complete sex, age, and anthropometric information contributed data to linear and logistic regressions examining time trends and associations between demographic characteristics and overweight/obesity.
Results: The prevalence of overweight (body mass index 25-<30 kg/m2) generally increased, from 25.8% (1989) to 37.2% (2012), peaking at 37.9% (2011). The prevalence of obesity (body mass index ≥30 kg/m2) also increased from 5.6% (1989) to 8.0% (2012), peaking at 12.3% (2009); 2005-2009 annual prevalence exceeded 10%. The most consistent demographic characteristics predicting overweight/obesity were male sex, older age, Hispanic or Asian/Pacific Island race/ethnicity, and being married. There were no distinct geographic trends.
Conclusions: The US Army is not immune to the US obesity epidemic. Demographic characteristics associated with being overweight or obese should be considered when developing military-sponsored weight management programs for new soldiers.
---------------------
Changes in Body Mass Index Associated With Head Start Participation
Julie Lumeng et al.
Pediatrics, February 2015, Pages e449-e456
Objectives: The goal of this study was to determine if Head Start participation is associated with healthy changes in BMI.
Methods: The sample included children participating in Head Start between 2005 and 2013 and children from 2 comparison groups drawn from a Michigan primary care health system: 5405 receiving Medicaid and 19 320 not receiving Medicaid. Change in BMI z score from the beginning to the end of each of 2 academic years and the intervening summer was compared between groups by using piecewise linear mixed models adjusted for age, gender, and race/ethnicity.
Results: The total sample included 43 748 children providing 83 239 anthropometric measures. The Head Start sample was 64.9% white, 10.8% black, and 14.4% Hispanic; 16.8% of the children were obese and 16.6% were overweight at the initial observation. Children who entered Head Start as obese exhibited a greater decline in the BMI z score during the first academic year versus the comparison groups (β = –0.70 [SE: 0.05] vs –0.07 [0.08] in the Medicaid group [P < .001] and –0.15 [SE: 0.05] in the Not Medicaid group [P < .001]); patterns were similar for overweight children. Head Start participants were less obese, less overweight, and less underweight at follow-up than children in the comparison groups.
Conclusions: Preschool-aged children with an unhealthy weight status who participated in Head Start had a significantly healthier BMI by kindergarten entry age than comparison children in a primary care health system (both those receiving and those not receiving Medicaid).
---------------------
Edward Coffield et al.
American Journal of Public Health, February 2015, Pages e83-e89
Objectives: We investigated the body mass index (BMI; weight in pounds/[height in inches]2 × 703) of parents whose children participated in Shape Up Somerville (SUS), a community-based participatory research study that altered household, school, and community environments to prevent and reduce childhood obesity.
Methods: SUS was a nonrandomized controlled trial with 30 participating elementary schools in 3 Massachusetts communities that occurred from 2002 to 2005. It included first-, second-, and third-grade children. We used an inverse probability weighting estimator adjusted for clustering effects to isolate the influence of SUS on parent (n = 478) BMI. The model’s dependent variable was the change in pre- and postintervention parent BMI.
Results: SUS was significantly associated with decreases in parent BMIs. SUS decreased treatment parents’ BMIs by 0.411 points (95% confidence interval = −0.725, −0.097) relative to control parents.
Conclusions: The benefits of a community-based environmental change childhood obesity intervention can spill over to parents, resulting in decreased parental BMI. Further research is warranted to examine the effects of this type of intervention on parental health behaviors and health outcomes.
---------------------
Constrained choices? Linking employees' and spouses' work time to health behaviors
Wen Fan et al.
Social Science & Medicine, February 2015, Pages 99–109
Abstract:
There are extensive literatures on work conditions and health and on family contexts and health, but less research asking how a spouse or partners' work conditions may affect health behaviors. Drawing on the constrained choices framework, we theorized health behaviors as a product of one's own time and spouses' work time as well as gender expectations. We examined fast food consumption and exercise behaviors using survey data from 429 employees in an Information Technology (IT) division of a U.S. Fortune 500 firm and from their spouses. We found fast food consumption is affected by men's work hours — both male employees' own work hours and the hours worked by husbands of women respondents — in a nonlinear way. The groups most likely to eat fast food are men working 50 h/week and women whose husbands work 45–50 h/week. Second, exercise is better explained if work time is conceptualized at the couple, rather than individual, level. In particular, neo-traditional arrangements (where husbands work longer than their wives) constrain women's ability to engage in exercise but increase odds of men exercising. Women in couples where both partners are working long hours have the highest odds of exercise. In addition, women working long hours with high schedule control are more apt to exercise and men working long hours whose wives have high schedule flexibility are as well. Our findings suggest different health behaviors may have distinct antecedents but gendered work-family expectations shape time allocations in ways that promote men's and constrain women's health behaviors. They also suggest the need to expand the constrained choices framework to recognize that long hours may encourage exercise if both partners are looking to sustain long work hours and that work resources, specifically schedule control, of one partner may expand the choices of the other.
---------------------
Priming healthy eating. You can't prime all the people all of the time
Suzanna Forwood et al.
Appetite, June 2015, Pages 93–102
Objective: In the context of a food purchasing environment filled with advertising and promotions, and an increased desire from policy makers to guide individuals toward choosing healthier foods, this study tests whether priming methods that use healthy food adverts to increase preference for healthier food generalize to a representative population.
Methods: In two studies (Study 1 n = 143; Study 2 n = 764), participants were randomly allocated to a prime condition, where they viewed fruit and vegetable advertisements, or a control condition, with no advertisements. A subsequent forced choice task assessed preference between fruits and other sweet snacks. Additional measures included current hunger and thirst, dietary restraint, age, gender, education and self-reported weight and height.
Results: In Study 1, hunger reduced preferences for fruits (OR (95% CI) = 0.38 (0.26–0.56), p < 0.0001), an effect countered by the prime (OR (95% CI) = 2.29 (1.33–3.96), p = 0.003). In Study 2, the effect of the prime did not generalize to a representative population. More educated participants, as used in Study 1, chose more fruit when hungry and primed (OR (95% CI) = 1.42 (1.13–1.79), p = 0.003), while less educated participants' fruit choice was unaffected by hunger or the prime.
Conclusion: This study provides preliminary evidence that the effects of adverts on healthy eating choices depend on key individual traits (education level) and states (hunger), do not generalize to a broader population and have the potential to increase health inequalities arising from food choice.
---------------------
Perceptions of overweight in US and global cultures
William Johnson et al.
Eating Behaviors, April 2015, Pages 125–129
Abstract:
We explored the hypothesis that perceptions of overweight vary in accord with the prevalence of overweight in specific populations. The present study investigated this relationship in samples from diverse groups in the US and four other countries. The perceptual threshold for overweight is the scalar point at which individuals determine the transition from normal to overweight. Perceptual thresholds for overweight were obtained from 812 adults in Korea, Mexico, Ukraine, Tanzania, and the US (Black, Hispanic, White and college student samples). A linear relationship was observed between the perceptual threshold for overweight and the population prevalence (r = 0.52, adjusted R2 = 0.22, F (1/15) = 5.24, p < .05), and this relationship was considerably stronger in the non-US samples. This finding links with the results of other studies documenting the influence of the social environment on both weight perception and weight transmission. Together, they suggest that the socio-cultural milieu and weight norms are components of the obesogenic environment and argue for the inclusion of weight norm interventions in weight management programs and public health initiatives.
---------------------
David Moore & Sara Konrath
Journal of Consumer Psychology, January 2015, Pages 42–59
Abstract:
The goal of this paper is to examine whether individual differences in affect intensity predict people's responses to food advertisements. In doing so, we aim to uncover individual differences and situational factors that are associated with higher food cravings and other consumption-related responses. Studies 1 and 2 identified three mediators (emotional memories, weak impulse control, and the intensity of pleasure anticipation) which indirectly link affect intensity to food cravings and behavioral intentions. Studies 3 and 4 identified two moderators (vividness of advertisement, dieting status of participants) of the relationship between affect intensity and consumption-related outcomes. In Study 3 high affect intensity individuals reported stronger food cravings only in response to vivid advertising appeals. In Study 4, respondents with high levels of positive affectivity, a sub-dimension of affect intensity, experienced increased salivation, but especially when they were dieters exposed to vivid food images. Implications for theory development and for marketing and public policy strategists are discussed.