Abstract P299: Lifespan Body Mass Index Change by Race and Education: Gain and Loss During the Obesity Epidemic

Abstract

Introduction: The obesity epidemic in the United States accelerated in the late 1970’s and has lifelong effects. Longitudinal patterns of racial/ethnic and socioeconomic differences in weight gain across the lifespan are relatively uncharacterized. Hypothesis: Weight gain starts earlier and is larger in individuals who are black or have less education compared to those who are white or have higher education; weight loss after midlife shows similar patterns. Methods: We analyzed body mass index (BMI, kg/m2) changes in 14,291 ARIC participants (ages 45 - 64) followed from Visit 1 (1987 - 89) to Visit 5 (2011 - 13, Table 1). Participant BMI at age 25 was ascertained by self-report at the time of study enrollment. BMI change between these time points was categorized as stable (<+/-2 kg/m2, average of <+/-13 lbs.), increasing or decreasing (>+/-2 kg/m2) and analyzed using multinomial logistic regression. Results: Table 1 shows BMI change and its associations with race and education. BMI change from age 25 to visit 1 (median age: 54) increased in 71%, was stable in 25% and decreased in 4% of participants. In midlife (visit 1 [1987 - 89] to visit 4 [1996 - 98]), an increase in BMI was more common (33%) compared to a decrease in BMI (7%). However, at older age (visit 4 [1996 - 98] to visit 5 [2011 - 2013]), both an increase and decrease in BMI (23% and 21% respectively) were common. Multinomial logistic regression demonstrated that being black, and having lower education, was consistently associated with weight gain from age 25 to midlife (visit 1). Interestingly, weight loss was also more common among blacks than whites, particularly at older age. Conclusion: Increases in BMI over the lifespan are common; weight gain from young adulthood to midlife, and both further weight gain and weight loss are common at older ages. Compared to whites, blacks experience more weight gain to midlife and greater late life weight loss. The implications for cardiovascular risk for weight gain and weight loss (a subset of which may mark poor health) needs to be explored.