A cross-national comparison of obesity using BMI-for-age percentiles: results from the Canadian longitudinal study on aging (CLSA) and the United States health and retirement study (HRS).

Obesity prevalence is increasing in both the United States (US) and Canada concurrently with demographic shifts, resulting in increasingly older populations with a high prevalence of obesity. Older adults have unique risks factors and outcomes related to obesity, such as age-related physiologic changes over time, that need to be considered when assessing obesity. In a comparison of data from the Canadian Longitudinal Study on Aging (CLSA) and the United States Health and Retirement Study (HRS), we use BMI-for-age percentile curves to examine obesity in the US and Canada in individuals 50+ years. Overall, BMI values were higher among individuals in the US and declined with chronological age in both countries. BMI values were higher among women than men in both countries. BMI-for-age percentiles reached a peak at a younger age among women in Canada compared to in individuals in the US. Using a novel measurement of obesity, the present work describes differences in obesity in older adults in Canada and the US and highlights the need for future work in obesity research in age- and sex- disaggregated contexts.