Personality and the prediction of weight loss and relapse in the treatment of obesity.

Objective: This prospective study examined whether stable personality traits, as measured by the Karolinska Scales of Personality (KSP), predicted initial weight loss or long-term maintenance in obesity patients.
Method: The KSP was administered to 102 obese patients prior to entering an 8-week weight loss program. Patients were weighed again at the end of treatment and at 3- and 12-month follow-up.
Results: The KSP did not predict initial weight loss after the 8-week program. Several of the KSP scales (Muscle Tension, Monotony Avoidance, Suspicion, and Guilt) had weak associations with 12-month relapse status. Weight gain at the 3-month follow-up was the strongest predictor of 12-month relapse status (O.R. = 0.46; 95% C.I. = 0.32, 0.66).
Discussion: Personality traits, as measured by the KSP, do not appear to be important predictors of initial weight loss or 12-month relapse status. Personality assessment may not substantially contribute to predicting treatment outcome in obesity research.