The Role of Free-Living Daily Walking in Human Weight Gain and Obesity

The Role of Free-Living Daily Walking in Human Weight Gain and Obesity James A. Levine , Shelly K. McCrady , Lorraine M. Lanningham-Foster , Paul H. Kane , Randal C. Foster and Chinmay U. Manohar From the Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota Address correspondence and reprint requests to James A. Levine, Endocrine Research Unit, Mayo Clinic, Rochester, MN 55905. E-mail: jim{at}mayo.edu Abstract OBJECTIVE —Diminished daily physical activity explains, in part, why obesity and diabetes have become worldwide epidemics. In particular, chair use has replaced ambulation, so that obese individuals tend to sit for ∼2.5 h/day more than lean counterparts. Here, we address the hypotheses that free-living daily walking distance is decreased in obesity compared with lean subjects and that experimental weight gain precipitates decreased daily walking. RESEARCH DESIGN AND METHODS —During weight-maintenance feeding, we measured free-living walking using a validated system that captures locomotion and body movement for 10 days in 22 healthy lean and obese sedentary individuals. These measurements were then repeated after the lean and obese subjects were overfed by 1,000 kcal/day for 8 weeks. RESULTS —We found that free-living walking comprises many (∼47) short-duration (