Physical Activity, Sedentary Behavior, and Sleep Before and After Bariatric Surgery and Associations with Weight Loss Outcome.

PURPOSE: Physical activity, sedentary behavior, and sleep have been linked to the likelihood of maintaining healthy body weight. This study aimed to determine objectively measured movement behaviors before and up to 18 months after bariatric surgery and to investigate whether preoperative levels of these movement behaviors and potential changes of these behaviors were associated with changes in body weight and boy composition. MATERIALS AND METHODS: Accelerometer determined total physical activity, moderate-to-vigorous physical activity (MVPA), light physical activity, sedentary behavior, and sleep (for six consecutive days and seven nights) were assessed approximately 3 months and 1-2 weeks before surgery as well as 6 and 18 months after surgery (n = 41). Body weight and body composition (waist circumference, fat mass, and fat-free mass) were determined at each visit. RESULTS: Mean weight loss 18 months after surgery was 42.0 ± 1.9 kg. There were no pre- to postoperative improvements in physical activity, sedentary behavior, or sleep. However, greater increases in levels of total physical activity and time spent in MVPA from 3 months before to 6 months after surgery predicted better weight loss and larger reductions in fat mass and waist circumference. Unexpectedly, a lower level of physical activity and a higher level of sedentary behavior before surgery predicted better weight loss outcomes. CONCLUSION: Objectively measured movement behaviors do not improve after bariatric surgery despite a substantial weight loss. However, increasing total physical activity and/or more time spent in MVPA after surgery may increase weight loss and lead to favorable changes in body composition.