Compensation for Smaller Portion Sizes and Portion Size Normality: Two Laboratory

Reducing food portion size is a potential strategy to reduce energy intake. However it is unclear at what point consumers compensate for reductions in portion size by increasing energy intake from other items. The investigators tested the hypothesis that reductions to food portion size will only result in significant compensatory eating when the reduced portion size is no longer visually perceived as 'normal'. In two within-subjects experiments, participants (Study 1: N = 45, M BMI = 26.9; Study 2: N = 37, M BMI = 26.9; 51% female) were served different sized portions of a lunchtime meal on three occasions: a 'large-normal', a 'small-normal', and a 'smaller than normal' portion. Both the reduction from 'large-normal' to 'small-normal' and from 'small-normal' to 'smaller than normal' portions represented the same change in food volume and energy content (84g, 77kcal Study 1; 98g, 117kcal Study 2). Participants were able to serve themselves additional helpings of the same food (Study 1), or dessert items (Study 2).