Objective. This study of the global epidemic of obesity among community-dwelling elderly explored the risk factors or correlates for obesity among the United States (U.S.) and Chinese elderly and what similar or different factors are associated with body mass index between the U.S. and Chinese elderly.

Design. Three secondary data sources were used: the 2003-2004 National Health and Nutrition Examination Survey (NHANES), the 2006 Texas Community Care Assessment Tool (CCAT), and the China Health and Nutrition Survey (CHNS).

Results. Among the overall U.S. elderly, the prevalence of severe obesity was ten percent (10%), twenty percent (20%) were moderately obese, and forty-one percent (41%) were overweight. A higher BMI was more common among those with greater functional limitations and greater burden of diseases. However, being obese was not significantly associated with socioeconomic status, caloric intake, or daily physical activity.

Weight problems were more prevalent among the low-income U.S. elderly. Approximately half of the sample members were obese, while an additional 28% were overweight. Obesity was more likely to occur among females, while it was less likely among those who were older, more cognitively impaired, or a smoker. As compared to overweight, obesity was more likely to happen among participants who have greater pain symptoms.

The longitudinal study among the Chinese elderly showed a relatively different picture. The prevalence of overweight or obesity was 33%. Moderate or heavy working activities and smoking decreased the risk of having excess body fat, while higher caloric intake and drinking alcohol increased this risk. More important, the protective effect of working activities against overweight or obesity was valid across different income and age groups.

Conclusions. (1) The current research among the U.S. elderly suggests that the traditional predictors of obesity in younger populations are of limited utility in modeling the dynamics of obesity among the elderly. Instead, when attempting to understand these dynamics among elderly individuals, our results imply that one must look to issues like disease states and functional impairment for enlightenment. (2) The significantly high prevalence of obesity (49%) among the low-income U.S. elderly identifies the disproportionate health disparities of the obese and calls policy makers to combat the obesity epidemic among those who stand lower on the social ladder. (3) The current study suggests that such favorable behavioral changes as increasing physical activity as well as reducing caloric and alcohol consumption can effectively decrease overweight and obesity among the Chinese elderly. (4) The research suggests that both U.S. and China are in the fourth stage of nutritional transition theory in terms of increasing obesity epidemic and unfavorable behavioral changes. However, obesity among the U.S. elderly was more common to those who have a greater burden of diseases and functional limitations, while overweight or obesity among the Chinese elderly was determined by behavioral and socioeconomic factors, which were non-significant among the U.S. elderly.