Early-Life Social Origins of Later-Life Body Weight Tetyana Pudrovska Pennsylvania State University Eric Reither Utah State University Ellis Logan Aliza Richman Pennsylvania State University

Social Inequality in Body Weight Low socioeconomic status is associated with higher rates of overweight and obesity NLSY 1979: Growing within-cohort inequality with age Source: C.L. Baum, C.J. Ruhm, Journal of Health Economics 28 (2009) 635–648

Social Inequality in Body Weight Two mechanisms explaining the association between SES and body weight: Low SES  Overweight and obesity Overweight and obesity  Low SES Two disparate strands of research Reciprocal relationships between body weight and SES have not received sufficient attention The social determinants of overweight and obesity originate early in life Children from disadvantaged socioeconomic backgrounds are more likely than higher-SES children to be overweight and obesity in adulthood and late life (Giskes et al. 2008; Langenberg et al. 2003)

Social Inequality in Body Weight How exactly does early-life SES affects later-life body weight? We explore to what extent the reciprocal relationship between SES and body weight over the life course convey the effect of early-life SES Socioeconomic disadvantage and higher body mass are simultaneously antecedents and consequences of each other

Overarching Framework

Data The Wisconsin Longitudinal Study (WLS) 10,317 non-Hispanic white men and women born in 1939 Graduated from Wisconsin high schools in 1957 Three waves: Age 18 in 1957 Age 36 in 1975 Age 54 in 1993

Measures SES in 1957: father’s and mother’s education, family income, and father’s occupation, occupational education and occupational income Status attainment: Academic performance in high school is based on high school grades in 1957 converted into a percentile rank SES in 1975: education, household wealth, household income, occupation, occupational education and occupational income

Measures Body weight: BMI in 1993 Relative body mass (RBM) in adolescence is coded from facial adiposity in high school yearbook pictures (Reither, Hauser, and Swallen 2009) Six coders assigned RBM scores separately for boys and girls on scale ranging from 1 (the lowest) to 11 (the highest).

Measures Control variables 1957: Grew up with both parents, lived in a rural area, mother worked for pay 1993: marital and parental status

Methods Structural equation modeling (SEM) to examine reciprocal life-course effects of body mass and SES Decomposition of the total effect of early-life disadvantage into direct and indirect effects Multiple-group analysis to formally test gender differences

Results Total effect: Early-life socioeconomic disadvantage is related to higher BMI in 1993 at age 54 a standard-deviation increase in disadvantage is associated with extra 15 pounds for a woman who is 5’5” tall and weighs 150 lb. and extra 10 pounds for a man who is 6 feet tall and weighs 190 lb. The effect of early-life SES is significantly stronger among women

Results: Pathways

Results: Effect Decomposition

Summary of Results Socioeconomic disadvantage at age 18 is related to higher BMI at age 54, especially among women Mechanisms: Perpetuation of socioeconomic disadvantage over life course: Early disadvantage increases later disadvantage Socioeconomic disadvantage in later life is related to heavier weight, and more closely for women than men Body mass in adolescence among women: Low early-life SES significantly increases girls’ body mass in adolescence Adolescent body mass is strongly and positively related to BMI in midlife among both men and women

Summary of Results Academic performance and SES: Higher body mass in adolescence has a large adverse effect on high school grades among girls but not boys Lower grades lead to lower SES Direct effect of adolescent body mass on SES in adulthood beyond high school grades

Conclusion A complex chain of risk: Body mass and SES are both determinants and consequences of each other over the life course via mutually-reinforcing effects Women experience more adverse effects than men of both low SES and heavier weight