Group Cognitive Remediation Therapy Prior to Behavioral Weight Loss Treatment for Adults With Severe Obesity: A Randomized Clinical Trial (CRT Study)

Objective: Individuals with obesity show executive dysfunctions that have been implicated in weight management failure. Initial evidence suggests that cognitive remediation therapy (CRT) conducted after behavioral weight loss (BWL) treatment improves weight loss and executive function, but efficacy for CRT conducted before BWL treatment is unknown. This study investigated whether group CRT in adults with Class II or III obesity (body mass index, BMI >= 35 kg/m(2)) improves weight loss, executive function, weight management behavior, and mental and physical health in real-world group BWL treatment. Method: In this prospective single-center, assessor-blind trial (DRKS00009333), 270 adults with Class II and III obesity (age 44.5 +/- 12.8 years, BMI 45.6 +/- 6.9 kg/m(2), and 68.9% women) were randomized to CRT with 8 group sessions over 2 months versus no treatment control, followed by routine BWL treatment of up to 12 months for both groups. The primary outcome was percent weight change at 6 months. Secondary outcomes included executive functions, weight management behaviors, and mental and physical health. Results: In intent-to-treat analyses, overall weight loss after 6 months was 1.2%, 95% CI [-2.0% to -0.4%], p = .002. The difference between arms was 0.4%, 95% CI [-1.1% to 1.8%], p = .629, Cohen's d = 0.09, after 6 months and 0.3%, 95% CI [-1.5% to 2.2%], p = .721, Cohen's d = 0.01, after 12 months. Improvements in most secondary outcomes including executive functions were seen at most time points, however, without differences between arms. Conclusions: Group CRT versus no treatment prior to real-world BWL treatment in adults with Class II and III obesity does not improve weight loss.