Sitting time and long-term weight change in adolescents with severe obesity undergoing surgical and nonoperative weight management.

Background: Prolonged sitting time has been associated with numerous deleterious effects on humans. The degree to which sitting time influences weight loss outcomes of obesity treatments is poorly understood.

Objectives: The objective was to characterize and describe the amount of time spent sitting in an adolescent bariatric surgical and nonoperative cohort and evaluate its relationship with long-term change in body mass index (BMI).

Setting: Tertiary care hospital, United States.

Methods: From 2011 to 2014, a 1-time study visit was conducted to collect long-term outcomes of Roux-en-Y gastric bypass (RYGB; n = 58) and nonoperative (n = 30) management of adolescents with severe obesity. The International Physical Activity Questionnaire was used to assess sitting time. Linear regression was used to evaluate the association between sitting time and percent BMI change from baseline.

Results: A total of 88 patients participated in the long-term follow-up visit at an average of 8 years from baseline. Percent BMI loss for participants who underwent RYGB (mean age at follow-up 25 yr) and for nonoperative (mean age at follow-up 23 yr) participants was -29% and +8%, respectively. The surgical group reported a median sitting time of 5.1 hr/d, while the nonoperative group reported a median sitting time of 7.0 hr/d (P = .11). Increasing sitting time was significantly associated with decreased percent BMI loss (P < .01).

Conclusions: RYGB was associated with long-term weight loss. Those participants with and without prior RYGB self-reported similar amounts of time spent sitting each day. Irrespective of whether participants had previously undergone surgery, lower levels of sitting time were found to be associated with greater BMI loss many years later.