Variation in the effects of family background and birth region on adult obesity: Results of a prospective cohort study of a Great Depression-era American cohort Chronic Disease epidemiology

Abstract

Background: Studies have identified prenatal and early childhood conditions as important contributors to weight status in later life. To date, however, few studies have considered how weight status in adulthood is shaped by regional variation in early-life conditions, rather than the characteristics of the individual or their family. Furthermore, gender and life course differences in the salience of early life conditions to weight status remain unclear. This study investigates whether the effect of family background and birth region on adult obesity status varies by gender and over the life course. Methods: We used data from a population-based cohort of 6,453 adults from the Health and Retirement Study, 1992-2008. Early life conditions were measured retrospectively at and after the baseline. Obesity was calculated from self-reported height and weight. Logistic models were used to estimate the net effects of family background and birth region on adulthood obesity risk after adjusting for socioeconomic factors and health behaviors measured in adulthood. Four economic and demographic data sets were used to further test the birthplace effect. Results: At ages 50-61, mother's education and birth region were associated with women's obesity risk, but not men's. Each year's increase in mother's education significantly reduces the odds of being obese by 6 % (OR∈=∈0.94; 95 % CI: 0.92, 0.97) among women, and this pattern persisted at ages 66-77. Women born in the Mountain region were least likely to be obese in late-middle age and late-life. Measures of per capita income and infant mortality rate in the birth region were also associated with the odds of obesity among women. Conclusions: Women's obesity status in adulthood is influenced by early childhood conditions, including regional conditions, while adulthood health risk factors may be more important for men's obesity risk. Biological and social mechanisms may account for the gender difference.