Euna Han

CONSUMPTION PATTERNS OF SUGAR SWEETENED BEVERAGES IN THE UNITED STATES

BACKGROUND Few previous studies have investigated consumption distributions of sugar-sweetened beverages (SSBs) over time and individual-level associations despite recent interest in SSBs regarding obesity control. OBJECTIVE To assess consumption patterns and individual-level associations. DESIGN Trend and cross-sectional analyses of 24-hour dietary recall data and demographic characteristics and socioeconomic status (SES) drawn from National Health and Nutrition Examination Survey (1999-2000, 2001-2002, 2003-2004, 2005-2006, and 2007-2008) data. PARTICIPANTS/SETTING Children (aged 2 to 11 years, n=8,627), adolescents (aged 12 to 19 years, n=8,922), young adults (aged 20 to 34 years, n=5,933), and middle-aged and elder adults (aged ≥35 years, n=16,456). STATISTICAL ANALYSES PERFORMED Age-stratified regression analyses for SSBs overall and by subtypes. RESULTS The prevalence of heavy total SSB consumption (≥500 kcal/day) increased among children (4% to 5%) although it decreased among adolescents (22% to 16%) and young adults (29% to 20%). Soda was the most heavily consumed SSB in all age groups except for children. Prevalence of soda consumption decreased, whereas heavy sports/energy drink consumption tripled (4% to 12%) among adolescents. Black children and adolescents showed higher odds of heavy fruit drink consumption (odds ratios 1.71 and 1.67) than whites. Low-income children had a higher odds of heavy total SSB consumption (odds ratio 1.93) and higher energy intake from total SSBs and fruit drinks (by 23 and 27 kcal/day) than high-income children. Adolescents with low- vs high-educated parents had higher odds of heavy total SSB consumption (odds ratio 1.28) and higher energy intake from total SSBs and soda (by 27 and 21 kcal/day). Low vs high SES was associated with a higher odds of heavy consumption of total SSBs, soda, and fruit drinks among adults. CONCLUSIONS Prevalence of soda consumption fell, but consumption of nontraditional SSBs rose. Heterogeneity of heavy consumption by SSB types across racial/ethnic subpopulations and higher odds of heavy SSB consumption among low-SES populations should be considered in targeting policies to encourage healthful beverage consumption.

Weight and wages: fat versus lean paychecks

Past empirical work has shown a negative relationship between the body mass index (BMI) and wages in most cases. We improve on this work by allowing the marginal effect of non-linear BMI groups to vary by gender, age, and type of interpersonal relationships required in each occupation. We use the National Longitudinal Survey of Youth 1979 (1982-1998). We find that the often-reported negative relationship between the BMI and wages is larger in occupations requiring interpersonal skills with presumably more social interactions. Also, the wage penalty increases as the respondents get older beyond their mid-twenties. We show that being overweight and obese penalizes the probability of employment across all race-gender subgroups except black women and men. Our results for the obesity-wage association can be explained by either consumers or employers having distaste for obese workers.

Field validation of secondary commercial data sources on the retail food outlet environment in the U.S.

This study used direct field observations with interior assessments of outlets to validate food store and restaurant data from two commercial business lists conditional on classification of outlet type, including supermarkets, grocery stores, convenience stores, full-service restaurants and fast food restaurants. The study used a stratified random sample that included 274 urban census tracts across 9 counties from the Chicago Metropolitan Statistical Area (MSA) and 46 suburban and 61 rural census tracts across 13 counties from a 50-mile buffer surrounding the MSA. Results showed that agreement between the field observations and the commercial business lists for the food store and restaurant outlets was generally moderate (ranging from fair to good). However, when the listed data were validated based on an exact classification match, agreement was only fair (ranging from poor to moderate) and, in particular, poor for fast food restaurants. The study also found that agreement levels for some outlet types differed by tract characteristics. Commercial databases must be used with caution as substitutes for on the ground data collection.

Energy Intake from Restaurants: Demographics and Socioeconomics, 2003–2008

BACKGROUND Eating food away from home and restaurant consumption have increased over the past few decades. PURPOSE To examine recent changes in calories from fast-food and full-service restaurant consumption and to assess characteristics associated with consumption. METHODS Analyses of 24-hour dietary recalls from children, adolescents, and adults using nationally representative data from the 2003-2004 through 2007-2008 National Health and Nutrition Examination Surveys, including analysis by gender, ethnicity, income, and location of consumption. Multivariate regression analyses of associations between demographic and socioeconomic characteristics and consumption prevalence and average daily caloric intake from fast-food and full-service restaurants. RESULTS In 2007-2008, 33%, 41%, and 36% of children, adolescents, and adults, respectively, consumed foods and/or beverages from fast-food restaurant sources and 12%, 18%, and 27% consumed from full-service restaurants. Their respective mean daily caloric intake from fast food was 191, 404, and 315 kcal, down by 25% (p ≤ 0.05), 3%, and 9% from 2003-2004; and among consumers, intake was 576, 988, and 877 kcal, respectively, down by 12% (p ≤ 0.05), 2%, and 7%. There were no changes in daily calories consumed from full-service restaurants. Consumption prevalence and average daily caloric intake from fast-food (adults only) and full-service restaurants (all age groups) were higher when consumed away from home versus at home. There were some demographic and socioeconomic associations with the likelihood of fast-food consumption, but characteristics generally were not associated with the extent of caloric intake among those who consumed from fast-food or from full-service restaurants. CONCLUSIONS In 2007-2008, fast-food and full-service restaurant consumption remained prevalent and a source of substantial energy intake.

Genetic Information, Obesity, and Labor Market Outcomes

Economists have argued that obesity may lead to worse labor market outcomes, especially for women. Empirical methods to test this hypothesis have not thus far adequately controlled for the endogeneity of obesity. We use variation in genotype to predict variation in phenotype (obesity). Genetic information from specific genes linked to obesity in the biomedical literature provides strong exogenous variation in the body mass index and thus can be used as instrumental variables. These genes predict swings in weight of between 5 and 20 pounds for persons between five and six feet tall. We use additional genetic information to control for omitted variables correlated with both obesity and labor market outcomes. We analyzed data from the third wave of the Add Health data set, when respondents are in their mid-twenties. Results from our preferred models show no effect of lagged obesity on the probability of employment or on wages, for either men or women. This paper shows the potential of using genetic information in social sciences.

Economic Contextual Factors, Food Consumption, and Obesity among U.S. Adolescents

Adolescents have poor dietary behaviors and high overweight prevalence. Economic contextual factors such as food prices and food store and restaurant availability are hypothesized and increasingly being explored empirically as contributors to the obesity epidemic. Evidence showed that healthful compared with less healthful foods increasingly cost more and that fast food restaurants are increasingly available. In addition, racial, ethnic, and socioeconomic disparities have been documented in access to food outlets, particularly chain supermarkets, and such disparities have been shown to be increasing recently. Empirical evidence based on nationally representative U.S. adolescent data revealed that lower fruit and vegetable prices, higher fast food prices, and greater supermarket availability were related to higher fruit and vegetable consumption and lower BMI, in particular for BMI among teens who are overweight or at risk for overweight and who are low- to middle-socioeconomic status. The availability of fast food restaurants was not associated with youth BMI. Overall, this research implies that pricing interventions of taxes on energy-dense foods such as fast food and/or subsidies to healthful foods such as fruits and vegetables and policy efforts to improve access to supermarkets may help to improve adolescent weight outcomes.

Classification bias in commercial business lists for retail food stores in the U.S.

BackgroundAspects of the food environment such as the availability of different types of food stores have recently emerged as key modifiable factors that may contribute to the increased prevalence of obesity. Given that many of these studies have derived their results based on secondary datasets and the relationship of food stores with individual weight outcomes has been reported to vary by store type, it is important to understand the extent to which often-used secondary data correctly classify food stores. We evaluated the classification bias of food stores in Dun & Bradstreet (D&B) and InfoUSA commercial business lists.MethodsWe performed a full census in 274 randomly selected census tracts in the Chicago metropolitan area and collected detailed store attributes inside stores for classification. Store attributes were compared by classification match status and store type. Systematic classification bias by census tract characteristics was assessed in multivariate regression.ResultsD&B had a higher classification match rate than InfoUSA for supermarkets and grocery stores, while InfoUSA was higher for convenience stores. Both lists were more likely to correctly classify large supermarkets, grocery stores, and convenience stores with more cash registers and different types of service counters (supermarkets and grocery stores only). The likelihood of a correct classification match for supermarkets and grocery stores did not vary systemically by tract characteristics whereas convenience stores were more likely to be misclassified in predominately Black tracts.ConclusionResearches can rely on classification of food stores in commercial datasets for supermarkets and grocery stores whereas classifications for convenience and specialty food stores are subject to some systematic bias by neighborhood racial/ethnic composition.

Direct and indirect effects of body weight on adult wages.

Previous estimates of the association between body weight and wages in the literature have been conditional on education and occupation. In addition to the effect of current body weight status (body mass index (BMI) or obesity) on wages, this paper examines the indirect effect of body weight status in the late-teenage years on wages operating through education and occupation choice. Using the National Longitudinal Survey of Youth 1979 data, for women, we find that a one-unit increase in BMI is directly associated with 1.83% lower hourly wages whereas the indirect BMI wage penalty is not statistically significant. Neither a direct nor an indirect BMI wage penalty is found for men. However, results based on clinical weight classification reveal that the indirect wage penalty occurs to a larger extent at the upper tail of the BMI distribution for both men and women via the pathways of education and occupation outcomes. Late-teen obesity is indirectly associated with 3.5% lower hourly wages for both women and men. These results are important because they imply that the total effect of obesity on wages is significantly larger than has been estimated in previous cross-sectional studies.

Development and reliability testing of a food store observation form.

OBJECTIVE To develop a reliable food store observational data collection instrument to be used for measuring product availability, pricing, and promotion. DESIGN Observational data collection. SETTING A total of 120 food stores (26 supermarkets, 34 grocery stores, 54 gas/convenience stores, and 6 mass merchandise stores) in the Chicago metropolitan statistical area. MAIN OUTCOME MEASURES Inter-rater reliability for product availability, pricing, and promotion measures on a food store observational data collection instrument. ANALYSIS Cohens kappa coefficient and proportion of overall agreement for dichotomous variables and intra-class correlation coefficient for continuous variables. RESULTS Inter-rater reliability, as measured by average kappa coefficient, was 0.84 for food and beverage product availability measures, 0.80 for interior store characteristics, and 0.70 for exterior store characteristics. For continuous measures, average intra-class correlation coefficient was 0.82 for product pricing measures; 0.90 for counts of fresh, frozen, and canned fruit and vegetable options; and 0.85 for counts of advertisements on the store exterior and property. CONCLUSIONS AND IMPLICATIONS The vast majority of measures demonstrated substantial or almost perfect agreement. Although some items may require revision, results suggest that the instrument may be used to reliably measure the food store environment.

The validity of genes related to neurotransmitters as instrumental variables

Health economics has a tradition of evaluating the models of instrumental variables (IV) used in our field. For example, French and Popovici (2011) assess the instruments used in 60 recent studies measuring the effect of substance use (alcohol, illicit drugs, and tobacco) on various outcomes. Rashad and Kaestner (2004) evaluate the instruments used by Sen (2002) and Rees and colleagues (2001) to identify the effect of alcohol on risky sex among adolescents. Terza et al. (2008) review the health economics literature that applies linear IV methods in inherently nonlinear regression settings. In this editorial we discuss the IVs used in Fletcher and Lehrer (2009a), hereafter FL, to estimate the effect of health conditions on educational attainment. We focus on FL because it is novel, well-written, and careful in many ways; it won the 2009 Victor R. Fuchs award for ‘the best research paper with the potential to spawn new research in an underdeveloped area of health economics or health policy’. The use of genes as IVs (and in other empirical capacities) is likely to become more widespread as large social science datasets continue to add data from genetic assays. Therefore, consideration of this method is timely and likely to be useful in the future. Our comments should not be interpreted as exclusively about FL, but also apply to other papers in this emerging area of empirical health economics (e.g. Ding et al., 2009; Fletcher and Lehrer, 2009b), including our own (Norton and Han, 2008). FL estimate IV models using data from the third wave of the National Longitudinal Survey of Adolescent Health (Add Health) to test whether overweight (based on self-reported weight and height), depression (based on the 20-item Center for Epidemiologic Studies-Depression Scale), and attention deficit and hyperactivity disorder or ADHD (based on 18 retrospective questions) affect years of schooling completed when respondents were on average 22 years old. FL argue persuasively that these measures of physical and mental health are endogenous to educational attainment. For example, poor grades in school may contribute to depression (reverse causality) and unobserved factors, such as rate of time preference, may contribute to both poor health and worse educational outcomes. As a result, simple regression would result in biased estimates of the effect of health on educational attainment. FL address the endogeneity of health by using genes as IVs. The specific IVs they use, listed in column 1 of Table I, are genes related to the neurotransmitters dopamine and serotonin. Fletcher and Lehrer (2009b) note that geneticists have linked these specific genes to overweight, depression, and ADHD, and that these correlations make sense in light of the fact that neurotransmitters affect mood, attention, and are associated with feelings of pleasure and reward, and thus serve as positive reinforcement for certain decisions. For example, people who are genetically predisposed to low levels