Temperament and one-year outcome of gastric bypass for severe obesity

The role of temperament traits in shaping the outcome of gastric bypass for severe obesity has not been established yet. This study evaluated whether temperament traits influence weight loss 1 year after gastric bypass, controlling for the potential confounding effect of Axis I and II disorders.

Forty-nine patients with severe obesity (body mass index = 46.4 ± 6.7) undergoing gastric bypass completed a thorough psychiatric evaluation before surgery, including structured interviews, rating scales, and questionnaire assessing the presence and severity of co-morbid Axis I and II disorders. Temperament was evaluated with the Temperament and Character Inventory (TCI). Weight loss 1 year after surgery was calculated as percent total weight loss (%TWL). Predictors of weight loss were investigated with multivariate linear hierarchical regression.

After accounting for psychiatric covariates, higher TCI persistence scores independently predicted 1-year outcome of gastric bypass and explained 40% of the variance in %TWL. Patients with low persistence scores showed a significantly lesser weight loss than patients with high scores.

Temperament traits denoting the ability to persevere in one's goals in spite of immediate frustration (persistence) are associated with greater weight loss 1 year after gastric bypass. These data suggest the utility of preoperatively assessing and reinforcing such capacity to optimize surgical outcome. Future research will clarify the behavioral mechanisms mediating this relationship as well as the influence of temperament on weight maintenance.