Sunday, November 18, 2012
Will work for food
Pierre-André Chiappori, Sonia Oreffice & Climent Quintana-Domeque
Journal of Political Economy, August 2012, Pages 659-695
We construct a marriage market model of matching along multiple dimensions, some of which are unobservable, in which individual preferences can be summarized by a one-dimensional index combining the various characteristics. We show that, under testable assumptions, these indices are ordinally identified and that the male and female trade-offs between their partners' characteristics are overidentified. Using PSID data on married couples, we recover the marginal rates of substitution between body mass index (BMI) and wages or education: men may compensate 1.3 additional units of BMI with a 1 percent increase in wages, whereas women may compensate two BMI units with 1 year of education.
Katie McLaughlin et al.
Journal of the American Academy of Child & Adolescent Psychiatry, forthcoming
Objective: To examine whether food insecurity is associated with past-year DSM-IV mental disorders after controlling for standard indicators of family socioeconomic status (SES) in a U.S. national sample of adolescents.
Method: Data were drawn from 6,483 adolescent-parent pairs who participated in the National Comorbidity Survey Replication Adolescent Supplement, a national survey of adolescents 13 to 17 years old. Frequency and severity of food insecurity were assessed with questions based on the U.S. Department of Agriculture's Food Security Scale (standardized to a mean of 0, variance of 1). DSM-IV mental disorders were assessed with the World Health Organization Composite International Diagnostic Interview. Associations of food insecurity with DSM-IV/Composite International Diagnostic Interview diagnoses were estimated with logistic regression models controlling for family SES (parental education, household income, relative deprivation, community-level inequality, and subjective social status).
Results: Food insecurity was highest in adolescents with the lowest SES. Controlling simultaneously for other aspects of SES, standardized food insecurity was associated with an increased odds of past-year mood, anxiety, behavior, and substance disorders. A 1 standard deviation increase in food insecurity was associated with a 14% increase in the odds of past-year mental disorder, even after controlling for extreme poverty. The association between food insecurity and mood disorders was strongest in adolescents living in families with a low household income and high relative deprivation.
Conclusions: Food insecurity is associated with a wide range of adolescent mental disorders independently of other aspects of SES. Expansion of social programs aimed at decreasing family economic strain might be one useful policy approach for improving youth mental health.
Journal of Poverty, Fall 2012, Pages 392-411
In 2009, 14.7% of U.S. households were food insecure, lacking consistent access to adequate food. Food insecurity increased in all residence areas with the "Great Recession" beginning in 2007, with the greatest increase in suburbs. The Current Population Survey Food Security Supplement was used to examine the likelihood of food insecurity across residence areas. Net of income and other household characteristics, suburban households were more likely to be food insecure than nonmetropolitan households and as likely to be food insecure as principal city households. The results suggest that during the recession economic hardship spread increasingly to suburbs.
Eric Finkelstein et al.
Journal of Health Economics, forthcoming
Using the 2006 Homescan panel, we estimate the changes in energy, fat and sodium purchases resulting from a tax that increases the price of Sugar-Sweetened Beverages (SSBs) by 20% and the effect of such a tax on body weight. In addition to substitutions that may arise with other beverages, we account for substitutions between SSBs and 12 major food categories. Our main findings are that the tax would result in a decrease in store-bought energy of 24.3 kcal per day per person, which would translate into an average weight loss of 1.6 pounds during the first year and a cumulated weight loss of 2.9 pounds in the long run. We do not find evidence of substitution to sugary foods and show that complementary foods could contribute to decreasing energy purchases. Despite their significantly lower price elasticity, the tax has a similar effect on calories for the largest purchasers of SSBs.
Rui Huang & Kristin Kiesel
European Review of Agricultural Economics, December 2012, Pages 797-820
This paper investigates the effects of soft drink bans in schools on purchases outside of schools. Using unique household-level data, we exploit the implementation of a state-mandated ban on soft drinks in Connecticut (USA) in a triple difference approach. We compare soft drink purchases of households with school-age children before and after implementation with purchases of households without school-age children in Connecticut, as well as households with and without school-age children in other states. Our analysis does not support the notion that school-age children compensate for the limited availability at school with increased consumption at home.
Lisa Bailey-Davis et al.
Objectives: To examine 3-year trends and spatial clustering in the prevalence of obesity among elementary-aged children in Pennsylvania.
Methods: Height and weight were measured for ∼980 000 children between ages 5 and 12 years, corresponding to kindergarten through grade 6 in 3 consecutive school years (2006-2007, 2007-2008, 2008-2009). These data were obtained at the school district level and reported to the Pennsylvania Department of Health in response to a state mandate requiring public schools to conduct annual surveillance of student growth. Analyses at the school district level (n = 501) regarding obesity prevalence (BMI ≥ 95th percentile) according to age and gender were conducted to examine associations over time and in relation to population density, geographic boundaries, and a calculated family distress index.
Results: The mean prevalence of obesity remained stable over 3 years at ∼17.6% of elementary-aged children. However, within the state, significant differences in the prevalence of obesity were identified. Schools in the most rural areas had adjusted obesity prevalence over 2 percentage points higher than urban schools. Consistent with secular findings for the nation in general, students with families living in socioeconomic distress exhibited upward trends in obesity risk.
Conclusions: School-based surveillance elucidates the disparate risk of obesity for younger students living in the most rural areas, a key finding for primarily rural states. Preventive interventions are needed to reach the most rural children with an emphasis on families where parents are single, are unemployed, have a lower income, and lower educational attainment.
Alison Buttenheim et al.
Social Science & Medicine, forthcoming
Obesity among the Mexican-origin adult population in the US has been associated with longer stays in the US and with being US- vs. Mexican-born, two proxies for acculturation. This pattern is less clear for Mexican-origin children and young adults: recent evidence suggests that it may be reversed, with foreign-born Mexican youth in the US at higher risk of obesity than their US-born Mexican-American counterparts. The objective of this study is to evaluate the hypothesis that the immigrant advantage in obesity prevalence for Mexican-origin populations in the US does not hold for children and young adults. We use data from the Los Angeles Family and Neighborhood Survey (N=1143) and the California Health Interview Survey (N=25,487) for respondents ages 4-24 to calculate the odds of overweight/obesity by ethnicity and nativity. We find support for the hypothesis that overweight/obesity prevalence is not significantly lower for first-generation compared to second- and third-generation Mexican-origin youth. Significantly higher obesity prevalence among the first generation was observed for young adult males (ages 18-24) and adolescent females (ages 12-17). The previously-observed protective effect against obesity risk among recent adult immigrants does not hold for Mexican-origin youth.
Willy Eriksen, Jon Sundet & Kristian Tambs
American Journal of Human Biology, forthcoming
Objectives: The aim of this study was to determine the relationship between paternal age at birth and the risk of obesity in young adulthood.
Methods: Data from the medical birth register of Norway were linked with register data from the Norwegian National Conscript Service and the national statistics agency, Statistics Norway. This study used the data on 346,609 registered males who were born at term in single birth without physical anomalies during 1967-1984 and who were examined at the time of the mandatory military conscription (age 18-20 years). The relationship between paternal age at birth and the occurrence of obesity (body mass index (BMI) ≥ 30.0 kg/m2) at conscription was examined using a multinomial logistic regression analysis with BMI < 25.0 kg/m2 as the reference outcome category.
Results: The relative risk of obesity at conscription increased linearly with increasing paternal age at birth but did not increase (P = 0.52) with maternal age at birth. Men born when their fathers were 50 years or older had a 55% (95% confidence interval (CI): 14%, 110%) higher relative risk of obesity than men born when their fathers were younger than 20 years of age, after adjustment for age at conscription, birth order, birth year, maternal age at birth, the mother's total number of children, and maternal and paternal education levels.
Conclusions: The risk of obesity in young Norwegian men increases with advancing paternal age at birth but does not increase with advancing maternal age at birth.
Muniza Mogri et al.
Clinical Endocrinology, forthcoming
Objective: Obesity in adult males is associated with hypogonadotropic hypogonadism. We evaluated the effect of obesity on plasma testosterone concentrations in pubertal and post pubertal young males.
Design And Methods: Morning fasting blood samples were obtained from 25 obese (BMI>95th percentile) and 25 lean(BMI<85th percentile) males between the ages 14-20 years with Tanner staging >4. Total and free testosterone and estradiol concentrations were measured by liquid chromatography tandem mass spectrometry and equilibrium dialysis. Free testosterone was also calculated using SHBG and albumin. C-reactive protein (CRP), insulin and glucose concentrations were measured and homeostasis model of insulin resistance (HOMA-IR) was calculated.
Results: After controlling for age and Tanner staging, obese males had a significantly lower total testosterone(10.5 vs 21.44nmol/l), free testosterone(0.22 vs 0.39nmol/l) and calculated free testosterone(0.26 vs 0.44nmol/l) concentrations as compared to lean males(p<0.001 for all). Obese males had higher CRP concentrations (2.8 vs 0.8mg/l; p<0.001), and HOMA-IR (3.8 vs 1.1; p<0.001) than lean males. Free testosterone concentrations were positively related to age and negatively to BMI, HOMA-IR and CRP concentrations. Total and free estradiol concentrations were significantly lower in males with subnormal testosterone in concentrations.
Conclusion: Testosterone concentrations of young obese pubertal and post pubertal males are 40-50% lower than those with normal BMI. Obesity in young males is associated with low testosterone concentrations which are not secondary to an increase in estradiol concentrations. Our results need to be confirmed in a larger number of subjects.
Janice Sabin, Maddalena Marini & Brian Nosek
PLoS ONE, November 2012
Overweight patients report weight discrimination in health care settings and subsequent avoidance of routine preventive health care. The purpose of this study was to examine implicit and explicit attitudes about weight among a large group of medical doctors (MDs) to determine the pervasiveness of negative attitudes about weight among MDs. Test-takers voluntarily accessed a public Web site, known as Project Implicit®, and opted to complete the Weight Implicit Association Test (IAT) (N = 359,261). A sub-sample identified their highest level of education as MD (N = 2,284). Among the MDs, 55% were female, 78% reported their race as white, and 62% had a normal range BMI. This large sample of test-takers showed strong implicit anti-fat bias (Cohen's d = 1.0). MDs, on average, also showed strong implicit anti-fat bias (Cohen's d = 0.93). All test-takers and the MD sub-sample reported a strong preference for thin people rather than fat people or a strong explicit anti-fat bias. We conclude that strong implicit and explicit anti-fat bias is as pervasive among MDs as it is among the general public. An important area for future research is to investigate the association between providers' implicit and explicit attitudes about weight, patient reports of weight discrimination in health care, and quality of care delivered to overweight patients.
Adam Hayward et al.
Proceedings of the Royal Society: Biological Sciences, 22 October 2012, Pages 4165-4173
Severe food shortage is associated with increased mortality and reduced reproductive success in contemporary and historical human populations. Studies of wild animal populations have shown that subtle variation in environmental conditions can influence patterns of mortality, fecundity and natural selection, but the fitness implications of such subtle variation on human populations are unclear. Here, we use longitudinal data on local grain production, births, marriages and mortality so as to assess the impact of crop yield variation on individual age-specific mortality and fecundity in two pre-industrial Finnish populations. Although crop yields and fitness traits showed profound year-to-year variation across the 70-year study period, associations between crop yields and mortality or fecundity were generally weak. However, post-reproductive individuals of both sexes, and individuals of lower socio-economic status experienced higher mortality when crop yields were low. This is the first longitudinal, individual-based study of the associations between environmental variation and fitness traits in pre-industrial humans, which emphasizes the importance of a portfolio of mechanisms for coping with low food availability in such populations. The results are consistent with evolutionary ecological predictions that natural selection for resilience to food shortage is likely to weaken with age and be most severe on those with the fewest resources.
Angela Kong et al.
Journal of Nutrition Education and Behavior, forthcoming
Objective: To compare the diets of African American and Hispanic families in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) prior to the 2009 food package revisions.
Methods: Mother-child dyads were recruited from 12 WIC sites in Chicago, IL. Individuals with 1 valid 24-hour recall were included in the analyses (n = 331 children, n = 352 mothers).
Results: Compared to their African American counterparts, diets of Hispanic mothers and children were lower (P < .001) in percentage of calories from fat, added sugars, sodium, and sweetened beverages, but higher (P < .001) in vitamin A, calcium, whole grains, fruit, and total dairy. However, no groups met national recommendations for percentage of calories from saturated fat, fiber, sodium, whole grains, vegetables, and total dairy.
Conclusions and Implications: There are racial/ethnic differences in dietary intake, and future research is needed to determine whether diets improve as a result of package revisions and whether uptake of these changes varies by race/ethnicity.
Obesity Reviews, December 2012, Pages 97-104
A substantial proportion of energy expenditure is utilized for maintenance of the ‘warm-blooded' or homoeothermic state. In normally active humans, this compartment of energy output approximates 40% of total energy expenditure. Many mammalian species utilize regulated decreases in temperature, such as hibernation or shallow torpor, as a means of energy conservation. Inherited forms of rodent obesity (ob/ob mouse, fa/fa rat) have lower core temperatures and withstand cold poorly. Obese humans, however, have normal core temperatures. This review addresses the role of core temperature in the metabolic economy of the obese state and raises the possibility that (i) lower temperatures may contribute to the increase in metabolic efficiency that accompanies weight loss in the obese; and (ii) that lower core temperatures may have initiated weight gain in the pre-obese state and that the normal temperatures in the obese may represent metabolic compensation to restore energy balance and limit further weight gain.
Daniele Campa et al.
PLoS ONE, November 2012
Several studies have shown that genetic factors account for 25% of the variation in human life span. On the basis of published molecular, genetic and epidemiological data, we hypothesized that genetic polymorphisms of taste receptors, which modulate food preferences but are also expressed in a number of organs and regulate food absorption processing and metabolism, could modulate the aging process. Using a tagging approach, we investigated the possible associations between longevity and the common genetic variation at the three bitter taste receptor gene clusters on chromosomes 5, 7 and 12 in a population of 941 individuals ranging in age from 20 to 106 years from the South of Italy. We found that one polymorphism, rs978739, situated 212 bp upstream of the TAS2R16 gene, shows a statistically significant association (p = 0.001) with longevity. In particular, the frequency of A/A homozygotes increases gradually from 35% in subjects aged 20 to 70 up to 55% in centenarians. These data provide suggestive evidence on the possible correlation between human longevity and taste genetics.
Margaret Carroll et al.
Journal of the American Medical Association, 17 October 2012, Pages 1545-1554
Context: Serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) contribute to atherosclerosis and its clinical consequences. Between the periods 1988-1994 and 1999-2002, mean TC and mean LDL-C declined in adults. During this time, there was an increase in the percentage of adults receiving lipid-lowering medications. Geometric mean triglyceride levels increased but mean high-density lipoprotein cholesterol (HDL-C) remained unchanged.
Objective: To examine trends in serum lipids in adults between 1988 and 2010.
Design, Setting, and Participants: Three distinct US cross-sectional National Health and Nutrition Examination Surveys, 1988-1994 (n = 16 573), 1999-2002 (n = 9471), and 2007-2010 (n = 11 766).
Main Outcome Measures: Mean TC, LDL-C, HDL-C, non-HDL-C, and geometric mean triglyceride levels and the prevalence of lipid-lowering medication use.
Results: Mean TC declined from 206 (95% CI, 205-207) mg/dL in 1988-1994 to 196 (95% CI, 195-198) mg/dL in 2007-2010 (P <.001 for linear trend); mean LDL-C declined from 129 (95% CI, 127-130) mg/dL to 116 (95% CI, 114-117) mg/dL (P <.001 for linear trend). Mean non-HDL-C declined from 155 (95% CI, 153-157) mg/dL in 1988-1994 to 144 (95% CI, 143-145) mg/dL in 2007-2010 (P <.001 for linear trend). Mean HDL-C increased from 50.7 (95% CI, 50.0-51.0) mg/dL during 1988-1994 to 52.5 (95% CI, 51.8-53.2) mg/dL in 2007-2010 (P =.001 for linear trend). Geometric mean serum triglyceride levels increased from 118 (95% CI, 114-121) mg/dL in 1988-1994 to 123 (95% CI, 119-127) mg/dL in 1999-2002 and decreased to 110 (95% CI, 107-113) mg/dL in 2007-2010 (P <.001 for quadratic trend). The prevalence of lipid-lowering medication use increased from 3.4% (95% CI, 2.9%-3.9%) in 1988-1994 to 15.5% (95% CI, 14.7%-16.3%) in 2007-2010 (P <.001 for linear trend). Among adults not receiving lipid-lowering medications, trends in lipids were similar to those reported for adults overall. Among obese adults, mean TC, non-HDL-C, LDL-C, and geometric mean triglycerides declined between 1988 and 2010.
Conclusion: Between 1988 and 2010, favorable trends in lipid levels have occurred among adults in the United States.
Esther Papies & Harm Veling
There is a growing consensus that our food-rich living environment contributes to rising numbers of people with overweight and obesity. Low-cost, effective intervention tools are needed to facilitate healthy eating behavior, especially when eating away from home. Therefore, we present a field experiment in a restaurant that tested whether providing subtle environmental diet reminders increases low-calorie food choices among both chronic and current dieters. For half of the participants, the menu was supplemented with diet-related words, as reminders of healthy eating and dieting. We recorded customers' choices of low-calorie or high-calorie items from the menu, and we assessed chronic and current dieting. Consistent with our hypotheses, we found that diet reminders increased choices for low-calorie foods, among both chronic and current dieters. After a diet reminder, around half of dieters made a healthy menu choice. This study demonstrates the efficacy of providing subtle diet reminders as a low-cost practical intervention to increase low-calorie food choices among weight-concerned individuals, who are motivated to regulate their eating behavior but have been found to often fail in food-rich environments.
Nandini Datta & James Kulik
Basic and Applied Social Psychology, September/October 2012, Pages 467-473
Times for college women in an exercise facility to begin working out on a target apparatus were unobtrusively recorded under three nearby peer conditions: fit peer, unfit peer, or no peer. In 116 trials, approach times were significantly faster in the unfit compared to the no-peer and fit-peer conditions, which did not differ significantly. Of those who approached (N = 75), neither exercise time nor post-exercise body satisfaction differed by condition. The results provide the first evidence that women in a naturalistic environment, when possible, manage their comparison opportunities and do so in a manner that may maintain body satisfaction.
Eric Robinson & Suzanne Higgs
PLoS ONE, November 2012
Social factors are known to influence food intake and choice. However, whether social influence acts on evaluations of food and drink liking has not been studied. Across two studies, we tested whether leading a participant to believe that other people do not like a food affects food liking evaluations. In Study 1, we exposed participants to social normative information suggesting a) that an in-group disliked orange juice, b) that an out-group disliked orange juice or c) that an in-group were neutral about orange juice. We then examined how much participants believed they liked orange juice. In Study 2, participants consumed a snack food before being led to believe that two previous participants had also eaten the food and either disliked or quite liked it. We asked participants to rate how much they had enjoyed eating the snack food. Across both studies, social influence was observed, as underlined by decreases in liking evaluations. In Study 1, beliefs about liking were only influenced by social normative information when the norm was expressed by an in-group. In Study 2, exposure to others' accounts of a negative experience with a food decreased evaluated liking of the recent consumption experience. These results suggest that social influence can act upon food liking evaluations.