Long-term weight loss maintenance after inpatient psychotherapy of severely obese patients based on a randomized study: predictors and maintaining factors of health behavior.

OBJECTIVE

The objective of this study was to identify predictors of long-term weight loss after inpatient psychodynamic or behavioral psychotherapy of severely obese patients.

METHODS

In a longitudinal study, obese patients [body mass index (BMI)>or=35 kg/m(2)] were randomly assigned to behavioral or psychodynamic inpatient treatment. The average treatment duration was 7 weeks. Two hundred sixty-seven obese patients, mostly female (85%), with psychiatric and somatic comorbidity (age, 20-64 years; BMI=35-74 kg/m(2)) were examined with standardized self-report scales at intake, discharge, 1-year follow-up, and 3-year follow-up.

RESULTS

Overall, 3 years after inpatient psychotherapy, irrespective of treatment setting, we found an average weight loss of about 1 BMI unit (2% or 3 kg). Effect size for weight loss was small (ES=0.26); changes in body image were stronger (ES=0.56). About 32% of patients achieved a long-term weight loss of >5%. In multiple regressions, weight loss was predicted by the attribution of overweight to eating habits, low dominance (Inventory of Interpersonal Problems), low life satisfaction, higher initial weight loss, and higher self-efficacy. Weight loss maintenance was predicted by cognitive control and current physical activity on follow-up.

CONCLUSION

In the long run, one third of patients could maintain or improve weight loss by inpatient psychotherapy. Lasting beneficial changes in body image and distress could also be found. The predictors of weight loss and weight loss maintenance identified in this study may be helpful for future modifications of psychotherapeutic intervention strategies.