OBJECTIVE: To estimate the prevalence and determine the risk factors and health associations among individuals with combined chronic obstructive pulmonary disease and obesity.METHODS: Canadian national health survey data from 1994 to 2007 (n=650,000) were used. The presence of COPD was based on health professional-diagnosed self-report. The presence of obesity, defined by body mass index ≥30 kg/m2, was identified using self-reported and measured height and weight. Hospitalization, homecare use, physical activity assessments and socioeconomic data were all self-reported.RESULTS: In 2005, the prevalence of obesity in COPD (n=3470) and non-COPD (n=92,237) individuals was 24.6% and 17.1%, respectively (P<0.0001). In contrast to the non-COPD group, in which obesity prevalence increased by 38% over 14 years, obesity prevalence increased by only 5% in people with COPD over this same time period. Female sex was the only independent risk factor for obesity in COPD. Previous smoking, residing in Atlantic Canada and the Territories, and low education level were independent risk factors for obesity in the non-COPD group, but not in the COPD group. The odds of physical activity limitation and health care utilization were significantly higher among obese individuals with COPD compared with nonobese COPD and obese non-COPD groups.CONCLUSIONS: The prevalence of obesity was higher in COPD, and exceeded that of the larger non-COPD group throughout the 13-year observation period. The presence of obesity in COPD was associated with significantly higher risk of severe activity limitation and increased health care utilization. The combination of obesity and COPD has major implications for health care delivery that has not been previously appreciated.