This naturalistic cohort study evaluates a meal cookery group-based occupational therapy intervention for adult inpatients and day patients with severe eating disorders. It also evaluates the Eating and Meal Preparation Skills Assessment (EMPSA) as an outcome measure, allowing clients pursuing recovery to rate ability and motivation to perform tasks related to preparing and eating ‘normal’ meals. Twenty-seven participants completed EMPSAs at their first, 10th and final sessions, plus 1 year later. The Ability subscale of EMPSA indicated significant improvements (p < 0.001) by the 10th session, which was maintained 1 year later. The Motivation subscale of EMPSA indicated no significant changes at the 10th session but highly significant improvements (p < 0.001) between the 10th and final session, which was maintained 1 year later. Internal consistency for EMPSA was demonstrated by Cronbach's alpha of 0.71 for Ability subscale and 0.95 for Motivation subscale. We conclude that the meal preparation group is effective and durable. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.