Associations between physical activity and mental health among bariatric surgical candidates.

To examine associations between physical activity (PA) and mental health among adults undergoing bariatric surgery.Cross sectional analysis was conducted on pre-operative data of 850 adults with ≥class 2 obesity. PA was measured with a step activity monitor; mean daily steps, active minutes, and high-cadence minutes (proxy for moderate-vigorous intensity PA) were determined. Mental health functioning, depressive symptoms and treatment for depression or anxiety were measured with the medical outcomes study 36-item short form, Beck depression inventory, and a study-specific questionnaire, respectively. Logistic regression analyses tested associations between PA and mental health indicators, controlling for potential confounders. Receiver operative characteristic analysis determined PA thresholds that best differentiated odds of each mental health indicator.Each PA parameter was significantly (p<.05) associated with a decreased odds of depressive symptoms and/or treatment for depression or anxiety, but not with impaired mental health functioning. After controlling for sociodemographics and physical health, only associations with treatment for depression and anxiety remained statistically significant. PA thresholds that best differentiated those who had vs. had not recently received treatment for depression or anxiety were <191 active minutes/day, <4750 steps/day, and <8 high-cadence minutes/day. Utilizing high-cadence minutes, compared to active minutes or steps, yielded the highest classification accuracy.Adults undergoing bariatric surgery who meet relatively low thresholds of PA (e.g., ≥8 high-cadence minutes/day, representative of approximately 1h/week of moderate-vigorous intensity PA) are less likely to have recently received treatment for depression or anxiety compared to less active counterparts.