High-protein meals may benefit fat oxidation and energy expenditure in individuals with higher body fat.

Aim: Fat oxidation is impaired in obesity. The aim of the present study was to determine if fat oxidation, seen in a high-protein meal response, was influenced by body composition.

Methods: Subjects were provided with control (14% protein, glycaemic index, GI 65), high-protein high-GI (33% protein, GI 74) and high-protein low-GI (35% protein, GI 45) meals. Substrate oxidation and energy expenditure were measured in room calorimeters over eight hours in 18 subjects. Results were compared using a repeated-measures anova with a customised post-hoc analysis (to compare the protein diets averaged vs control and to compare the low- and high-GI diets) and covariates in a linear model of the form: y = ' + ß1 × fat-free mass (kg) + ß2 × loge fat mass (kg).