Exercise After Clinically Significant Weight Loss

The Prescribed Exercise to Reduce Recidivism After Weight Loss Pilot (PREVAIL-P) study will evaluate the effect of aerobic exercise training amount on weight maintenance following clinically significant weight loss (CWL). Overweight and obese (BMI: 25-40 kg/m2) men and women (18-65 years old) complete an OPTIFAST diet (7%-10% weight loss). Participants that obtain CWL will be subsequently randomized to aerobic exercise training consistent with the minimum physical activity guidelines (\~150 min of moderate intensity exercise) or weight maintenance guidelines (200-300 min per wk. at moderate intensity) for 9 additional months. Specific Aim 1: To demonstrate the efficacy of the weight loss program in producing CWL and retention/adherence of the exercise intervention. Overweight and obese adults (N=39) will participate in an OPTIFAST weight loss program and supervised aerobic exercise training (\~550 metabolic equivalents minutes \[MET min. per week.\]) for 10 weeks. Participants who obtain CWL will be subsequently randomized to 16 weeks of aerobic training consistent with the minimum physical activity recommendations (\~550 MET min per week.) or weight maintenance guidelines (\~970 MET min per week). The percentage of participants that obtain at least 7% weight loss following OPTIFAST treatment, retention rates in the weight loss program, adherence to exercise levels, and changes in weight and cardiometabolic risk factors in response to the intervention will be evaluated. Specific Aim 2: To test the hypothesis that exercise levels consistent with weight maintenance recommendations leads to greater weight maintenance after CWL compared to the minimum physical activity recommendation levels. Overweight and obese adults (N=30) enrolled in VIDANT health's OPTIFAST program and have achieved at least 7% weight loss will be randomized to 36 weeks of aerobic exercise training consistent with the minimum public health guidelines for physical activity (\~550 MET min. per week.) or weight maintenance levels (\~970 MET min per week). The effect of the intervention will be evaluated on weight (primary) as well as main secondary measures (e.g. body fat, visceral fat, lipids, lipoprotein particles size/class, insulin sensitivity, blood pressure, arterial stiffness, systemic inflammation, fitness, and quality of life). The aforementioned cardiometabolic risk factors were selected because they can be improved specifically by weight loss and thus may respond differently to weight maintenance or regain.