The longitudinal effects of behavioral, health, and socio-demographic factors on body mass index among older Chinese adults

Objectives To examine the effects of behavioral, health, and socio-demographic factors on being overweight or obese among older Chinese adults. Methods This research uses panel data from the China Health and Nutrition Survey, which was designed to examine how social and economic transformation affected the health and nutritional status of residents. For these analyses, we used all available information on adults aged 60 years or older surveyed in 1997, 2000, 2004, and 2006 (N = 3,591). Body mass index (BMI) was dichotomized as normal (18.5-24.9 kg/m(2)) and overweight (25.0-29.9 kg/m(2))/obese (>= 30 kg/m(2)). Generalized estimating equations were used to estimate population-averaged (marginal) effects. Results The combined prevalence of overweight or obese was approximately 33%. Moderate or heavy non-leisure physical activities (OR = 0.39; 95% CI = 0.32-0.49) and smoking (OR = 0.69; 95% CI = 0.57-0.84) decreased the odds of being overweight or obese, while drinking alcohol (OR = 1.25; 95% CI = 1.05-1.50) increased the odds. For individuals in all income levels, the amount of non-leisure physical activity strongly affected the BMI among the older Chinese adults. Conclusions Active lifestyle interventions may help counter what could otherwise be a growing obesity epidemic in China.