Longitudinal change in physical activity and disability in adults.

Objectives: To prospectively examine whether physical activity or change in physical activity increases or decreases the risk of disability later in life.

Methods: Tobit regression models were used to examine the effect of physical activity at baseline and change from baseline on disability 10 and 20 years later in 6913 adults.

Results: Increasing recreational physical activity was associated with reduced risk of disability whereas reducing recreational physical activity increased the risk of disability after 10 years.

Physician evaluation of obesity in health surveys: "who are you calling fat?".

Previous research on status generalization suggests that physicians may use non-medical factors in their evaluation, interpretation, and treatment of persons presenting for care. This study compares physicians' evaluations of obesity with physical measurements of body stature and fat collected from a large national health examination survey. While the anthropometric measures are strong predictors of physician evaluations of obesity, between 13% and 19% of the respondents were classified in ways that could not be predicted from the anthropometric measures.