Nearly 20% of US citizens are disabled. Epidemiologic studies have shown that people with physical disabilities have a 1.2- to 3.9-fold increase in obesity prevalence. Obesity is becoming a serious problem in disabled individuals. The mechanisms by which obesity occurs in people with physical disabilities is not clear, but pathophysiological changes of body composition and energy metabolism, physical inactivity, and muscle atrophy all favor the development of obesity. Health professionals should identify disabled patients at risk and provide early prevention guidance. Research is needed to help generate detailed clinical guidelines to promote weight control among people with physical disabilities.