BACKGROUND: Controversy exists regarding whether the different daily balances of proteins between meals and snacks in a low-calorie diet may influence the effects on body composition (BC) results. Aim of this study is to evaluate BC changes made by a lifestyle intervention in a randomised homogeneous sample of two groups with equal daily caloric reduction but different protein distributions between meals.
METHODS: Forty-seven men and women (mean ± SD age: 32 ± 10 y; body mass index: 28.4 ± 2.4) consumed an energy-restricted diet (788 kcal/d below the requirement) for eight weeks in a free- living contest. Subjects consumed 90.1 g protein/d (1.10 ± 0.16 g · kg-1· d-1 ) and were randomised in an EVEN (16.7% at breakfast, 32.8% at lunch, 31.3% at dinner, 19.2% at snacks;n= 23) or UNEVEN (15.4% at breakfast, 36.6% at lunch, 34.9% at dinner, 12.4% at snacks;n= 24) distribution pattern. The nutritional characteristics and caloric deficit of the two diets were similar.
RESULTS: The total sample had an overall improvement in both BMI (-0.9 ± 0.6) and fat mass (FM: -2.3 ± 1.5), while lean body mass was preserved (LBM: 0.0 ± 0.7). There were no significant differences between the two groups in variations in BC.
CONCLUSIONS: In overweight and obese subjects undergoing a Mediterranean-type low-calorie diet, a different distribution of daily protein intake between meals and snacks does not result in significant differences in terms of FM loss and LBM maintenance. This is one of the first studies showing that nutritional dietary plans with different daily protein distribution show no particular differences in fat loss and lean mass maintenance.