Impact of Weight Loss on Physical Function

A calorie restricted diet based on estimates of total energy expenditure (TEE) obtained from the measured resting metabolic rate (RMR) during a wt stable period. TEE will be estimated by multiplying RMR by a factor of 1.1-1.3 to cover activity energy expenditure based on an assessment of physical activity levels at baseline using accelerometry. We will use the TEE to create an individualized dietary rx for each pt, subtracting up to 500 calories from the estimated TEE. To ensure micronutrient needs are being met, total calories will not be decreased below 1200 kcal per day, regardless of the estimated TEE. They will receive a standard exercise program that will be designed to promote exercise energy expenditure of approximately 1200 kcal/week. We will prescribe resistance training for 2 days per week with a loading intensity of 60% of 1 rep max and volume of 3 sets at 8 reps per exercise. Aerobic training will be prescribed for 3 days per week.

Placed on complete meal replacement (MR) using the OPTIFAST medical wt loss protocol. Pts will consume a min of 86 g of protein daily in 5-6 servings of MR. Min caloric intake will be 960 kcal/day with adjustments in intake made based on BMI and activity levels, holding the percent of calories from protein constant at 35%. The MRs provide 100% of daily recommended needs for micronutrients and will be supplied weekly at clinic visits by the study. Pts will begin to incorporate food into their routine beginning at week 13 with guidance from a dietitian. From weeks 13-26, caloric prescriptions will be between 1100 to 1600 kcal/day, using a combo of MRs and food. Will receive an exercise program designed to promote exercise energy expenditure of approximately 1200 kcal/week. We will prescribe resistance training for 2 days per week with a loading intensity of 60% of 1 rep max and volume of 3 sets at 8 reps per exercise. Aerobic training will be prescribed for 3 days per wk.