The Effects of Weight Loss and Exercise on Quality of Life

Abstract

PURPOSE: Health-related quality of life (HRQOL) is typically lower in overweight and obese populations compared to individuals of normal weight. Combined interventions of diet and aerobic exercise may improve HRQOL in this population, but the physiological predictors of these improvements are not well known. The primary purpose of the present study was to investigate the impact of weight loss and aerobic exercise on HRQOL as measured by the SF-36 in a population of overweight and obese individuals. Secondly, we sought to determine the impact of physiological mediators, such as body composition, weight loss, aerobic fitness, and insulin, glucose, and cholesterol levels on improvements in HRQOL. METHODS: The present study utilized data from the weight loss phase of the Prescribed Exercise to Reduce Recidivism After Weight Loss pilot (PREVAIL-P) study. This phase lasted 10 weeks and consisted of aerobic exercise on a treadmill, the OPTIFAST medically supervised weight loss program, and weekly lifestyle education classes. All measurements were taken at baseline and 10 weeks, following the weight loss intervention. For primary outcome measures, HRQOL was assessed using the SF-36v2. For secondary measures, weight was measured using a physician beam scale, aerobic fitness was assessed using a modified Balke protocol with a metabolic cart, body composition was assessed with a DEXA scan, and a blood draw sent to LabCorp was used to measure insulin, glucose, and cholesterol levels. RESULTS: The sample included 36 participants (mean age=46 years; 80.6% female). We observed significant improvements in all domains of HRQOL and CVD risk factors, with a mean clinically significant weight loss of 9.3%. Improvements in several of the SF-36 domains were significantly associated with weight loss, reductions in cholesterol, and changes in body composition. When controlling for weight loss, all correlations became non-significant except the association between LDL and vitality. All HRQOL improvements were also significantly correlated with baseline SF-36 scores. CONCLUSION: Results from the present study suggest that a combined OPTIFAST weight loss and aerobic exercise training program may lead to improvements in HRQOL, which may be dependent upon baseline HRQOL levels and overall weight loss. Beneficial improvements in HRQOL did not appear to be limited by lean mass changes with weight loss. This knowledge will help in designing effective treatment programs and interventions to improve HRQOL in overweight and obese individuals.