This is an ancillary study to E-Mechanic, which is an National Institutes of Health study in 198 individuals with the objective to understand why certain people fail to lose weight in exercise programs. In E-Mechanic changes in body weight, body composition, energy intake and energy expenditure are measured before and after 3 different exercise programs of 24 weeks in duration. The 3 exercise programs being compared are self-directed exercise, low dose exercise and high dose exercise. The goal of this ancillary study is to undertake comprehensive assessments of energy metabolism in a metabolic chamber in a group of 60 obese individuals enrolled in the main study. We will compare differences in the changes in 24h energy expenditure and spontaneous physical activity between the 3 exercise programs. We will also test if changes in energy metabolism might explain why people don't lose the expected amount of weight after 24 weeks of exercise.
The E-MECHANIC Ancillary Study will measure changes in 24-hour energy expenditure and spontaneous physical activity in a subset of 60 obese individuals enrolled in the main study. We aim to determine if changes in energy metabolism might explain why people don't lose the expected amount of weight in an exercise program.