A Randomized Trial Of High-Dairy-Protein, Variable-Carbohydrate Diets And Exercise On Body Composition In Adults With Obesity

Objective: This study determined the effects of 16-week high-dairy-protein, variable-carbohydrate (CHO) diets and exercise training (EXT) on body composition in men and women with overweight/obesity.Methods: One hundred and eleven participants (age 47 +/- 6 years, body mass 90.9 +/- 11.7 kg, BMI 3364 kg/m(2), values mean +/- SD) were randomly stratified to diets with either: high dairy protein, moderate CHO (40% CHO: 30% protein: 30% fat; similar to 4 dairy servings); high dairy protein, high CHO (55%: 30%: 15%; similar to 4 dairy servings); or control (55%: 15%: 30%; similar to 1 dairy serving). Energy restriction (500 kcal/day) was achieved through diet (similar to 250 kcal/day) and EXT (similar to 250 kcal/day). Body composition was measured using dual-energy X-ray absorptiometry before, midway, and upon completion of the intervention.Results: Eighty-nine (25 M/64 F) of 115 participants completed the 16-week intervention, losing 7.763.2 kg fat mass (P<0.001) and gaining 0.5061.75 kg lean mass (P<0.01). There was no difference in the changes in body composition (fat mass or lean mass) between groups.Conclusions: Compared to a healthy control diet, energy-restricted high-protein diets containing different proportions of fat and CHO confer no advantage to weight loss or change in body composition in the presence of an appropriate exercise stimulus.