Obesity, intentional weight loss and physical disability in older adults.

We examine obesity, intentional weight loss and physical disability in older adults. Based on prospective epidemiological studies, body mass index exhibits a curvilinear relationship with physical disability; there appears to be some protective effect associated with older adults being overweight. Whereas the greatest risk for physical disability occurs in older adults who are ≥class II obesity, the effects of obesity on physical disability appears to be moderated by both sex and race. Obesity at age 30 years constitutes a greater risk for disability later in life than when obesity develops at age 50 years or later; however, physical activity may buffer the adverse effects obesity has on late life physical disability. Data from a limited number of randomized clinical trials reinforce the important role that physical activity plays in weight loss programmes for older adults. Furthermore, short-term studies have found that resistance training may be particularly beneficial in these programmes as this mode of exercise attenuates the loss of fat-free mass during caloric restriction. Multi-year randomized clinical trials are needed to examine whether weight loss can alter the course of physical disablement in aging and to determine the long-term feasibility and effects of combining resistance exercise with weight loss in older adults.