Abstract 1266: Do Gender Differences Exist in the Relation of Physical Activity with Changes in Body Mass Index and Waist Circumference over 20 years: the CARDIA Study

Abstract

Public health guidelines recommend physical activity to minimize weight gain. Yet, the data are ambiguous; some studies show weaker associations between activity and adiposity/weight changes in women perhaps due to inability to control for gender differences in energy intake and fat distribution. We hypothesized that after accounting for energy intake and fat distribution, associations between high activity levels and changes in weight, body mass index (BMI) or waist circumference over 20 years would not differ by gender. Black and white adults ages 18 –30 from the CARDIA Study, an NHLBI sponsored multi-center longitudinal study, had anthropometric measures taken and activity habits assessed using an interviewer-based questionnaire at 7 exams over 20 years (n=3555). Generalized estimating equations were used to calculate average annual changes in weight (pounds), BMI (kg/m 2 ), and waist circumference (cm) by long-term activity level over 20 years, stratified by sex and baseline overweight status. High activity was associated with smaller gains in weight, BMI and waist circumference in men and women over 20 years (Table , weight data not shown). Formal interaction tests by sex and baseline overweight status were significant (p<0.05). When comparing high versus low activity, women showed larger differences in weight change than men. Compared with low activity, normal weight women with high activity gained 16.8 fewer pounds over 20 years while normal weight men gained 5.6 fewer pounds. Consistently high activity during young adulthood is associated with smaller gains in weight, BMI and waist circumference. The difference in weight gain between high and low activity is greater in women and persists after adjustment for energy intake. These results suggest that weight gain in young adults, particularly women, may be slowed by incorporating high activity into daily life in a manner that can be maintained over many years. Table: Average annual changes in BMI and waist circumference by long-term activity categories, stratified by gender and baseline overweight status