Expected benefits and motivation to weight loss in relation to treatment outcomes in group-based cognitive-behavior therapy of obesity.

PURPOSE: We aimed to determine cognitive drivers, expected to play a role in target reach and/or attrition in obesity programs. METHODS: We recorded the expected benefits of weight loss, weight targets, primary motivation for weight loss, perceived treatment needs, readiness and self-confidence to be successful and a battery of psychopathology questionnaires in 793 subjects with obesity (68% women; mean age 48.7; 46% obesity class III) enrolled into a group-based cognitive-behavioral treatment program. Their relevance on attrition and successful weight loss outcome were tested by logistic regression analysis. RESULTS: The expected benefits of weight loss scored very high in all physical, psychological and social areas, with differences between genders. Attrition rate was 24, 41 and 65% at 6-, 12-, and 24-month follow-up. Average weight loss was 5.8 ± 7.1 kg (- 4.8%) at 6 months, with 17% of cases (32% of continuers) maintaining weight loss > 10% at 24 months. After adjustment for confounders, attrition was reduced by concern for present health, motivation/consciousness of the importance of physical activity and need for support; treatment discontinuation was favored by concern for body image, by expectations for drug treatment or bariatric surgery, and by high-challenging weight loss targets. Male gender, higher BMI and concern for present health predicted weight loss > 10%, whereas concern for body appearance was associated with lower probability of attaining the desired weight loss targets. CONCLUSION: A more precise definition of needs and expectations might help tailor treatment to individual patients, but attrition rates and target reach remain difficult to predict. LEVEL OF EVIDENCE: Level V, descriptive studies.