OBJECTIVE: Overweight and obesity are health issues that are increasing worldwide. Patients with severe mental illness are particularly vulnerable for various reasons, including the intake of weight gain-associated drugs. In this pilot study, we targeted eating behavior as a predictor for medication-induced weight gain and developed a module of a prevention program ("Eating More Consciously") to be evaluated by psychiatric inpatients. METHODS: Thirty-three patients participated in a behaviorally oriented group therapy program with 2 modules of 120 minutes each and weekly follow-up measurements over 4 weeks. Measures included weight, laboratory parameters, the German versions of the Three-Factor Eating Questionnaire (Fragebogen Essverhalten; FEV) and the Food Craving Inventory (FCI) as well as a questionnaire on the implementation of the strategies in everyday life. RESULTS: Thirty-three participants completed both modules and felt that they had benefited from the module "Eating More Consciously". Fragebogen Essverhalten domain "cognitive restraint" scores increased significantly throughout the study ( = .039), and the FCI sum score decreased significantly ( = .003). CONCLUSION: We propose that the "Eating More Consciously" module is a promising approach to behavioral intervention in weight management in patients with severe mental illness. Prospective randomized controlled studies with a larger sample and a longer follow-up are needed.