To document preoperative outcomes of a behavioral lifestyle intervention delivered to patients prior to bariatric surgery in comparison to treatment as usual (insurance-mandated physician supervised diet).

Design and Methods:

After completing a baseline assessment, candidates for surgery were randomized to a 6-month, evidence-informed, manualized lifestyle intervention (LIFESTYLE, n = 121) or to preoperative care as usual (USUAL CARE, n = 119). At 6 months, 187 participants remained candidates for bariatric surgery and were included in the analyses.


LIFESTYLE participants lost significantly more weight than those receiving USUAL CARE [8.3 ± 7.8 kg vs. 3.3 ± 5.5 kg, F(1,183) = 23.6, P < 0.0001], with an effect size of 0.72. Additionally, logistic regression modeling indicated that LIFESTYLE patients were significantly more likely to lose at least 5% of initial body weight than those in USUAL CARE [OR (95% CI) = 2.94 (1.253, 6.903)], as were participants who were heavier [OR (95% CI) = 1.07 (1.001-1.14) for each unit increase in BMI] or with larger improvements in eating behaviors [OR (95% CI) = 1.1 (1.049, 1.145) for each unit increase on the Eating Behavior Inventory).


A behavioral lifestyle intervention for severely overweight individuals leads to clinically significant weight loss prior to bariatric surgery. Post-surgery follow-up will allow us to examine the impact of the preoperative intervention on postoperative outcomes.