Abstract P145: The Effect of Exercise Level on Weight Maintenance and Cardiometabolic Risk Factors After Clinically Significant Weight Loss: Results From the Prevail-p Study

Introduction: Clinically significant weight loss is associated with health benefits for overweight and obese adults. Participation in adequate amounts of physical activity is critical for weight maintenance. However, few studies in the literature have evaluated the amount of physical activity needed to promote weight maintenance in a supervised exercise training study with corresponding data on cardiovascular risk factors. Methods: Overweight and obese adults (N=39) completed a 10-week OPTIFAST ® weight loss program with supervised aerobic exercise training with the goal of achieving clinically significant weight loss (≥7%). Participants who met the weight loss goal were randomized to levels of aerobic training consistent with physical activity recommendations (PA-REC) (~550 MET minutes per week) or weight maintenance recommendations (WM-REC) (~970 MET minutes per week) for 18 additional weeks. Weight, body composition, and blood measures (e.g., fasting glucose, insulin, and lipids) were measured at baseline, after weight loss (10 weeks), and at follow-up (28 weeks). Results: Thirty-three of the 39 participants achieved clinically significant weight loss (~85%). There were reductions in weight (-8.8 kg), body fat (-2.1%), visceral fat (-120.4 g), along with other health indicators (systolic blood pressure [-6.8 mmHg], diastolic blood pressure [-5.9 mmHg], HOMA-IR [-2.4] and lipids) after the weight loss phase (all p’s< 0.05). Full data for the weight maintenance phase were available in 21 participants due to the COVID pandemic (PA-REC: 12, WM-REC:9). Larger improvements in cardiorespiratory fitness (as assessed by estimated METs [1.7 vs. 0 METs, p=0.01] and relative VO 2 peak [2.3 vs.0.5 ml/kg/min, p=0.04]) were observed in the WM-REC group compared to the PA-REC group, while changes in waist circumference (-2.4 vs. 0.5 cm, p=0.06), visceral fat (-45.7 vs. 8.2 g, p=0.06), and absolute VO 2 (0.1 vs. 0.2 L/min, p=0.09) approached significance. No significant changes were observed between groups for changes in weight, blood pressure, glucose metabolism, or lipid parameters during the maintenance phase (all ps>0.05). Discussion: Clinically significant weight loss combined with aerobic exercise resulted in improvements in cardiometabolic parameters. Exercise at levels associated with the weight maintenance guidelines resulted in greater improvements in cardiorespiratory fitness and may have the potential to improve measures of central adiposity to a greater extent than the minimum physical activity recommendations following weight loss. Future studies should evaluate the impact of different levels of aerobic exercise after clinically significant weight loss in long term interventions.