Increased protein intake and meal frequency reduces abdominal fat during energy balance and energy deficit

OBJECTIVE: Unrefined, complex carbohydrates and lean protein diets are used to combat obesity, although it's unknown whether more frequent meals may improve this response. The effects of consuming traditional (~15%) versus higher (~35%) protein intakes as three or six meals/day on abdominal fat, postprandial thermogenesis (TEM), and cardiometabolic biomarkers in overweight individuals during 28 days of energy balance (BAL) and deficit (NEG), respectively were compared. 

DESIGN AND METHODS: Overweight individuals (n = 30) were randomized into three groups: two high-protein groups (35% of energy) consumed as three (HP3) or six (HP6) meals/day and one group consumed three meals/day of a traditional intake (TD3). Following a 5-day baseline control (CON), subjects consumed their respective diets throughout a 56-day intervention consisting of two, 28 day phases: a BAL followed by a NEG phase (75% of energy needs). Total body fat (BF) and abdominal BF (ABF), body weight (BW), TEM, and fasting biomarkers were assessed at the end of CON, BAL, and NEG phases. 

RESULTS: BW remained stable throughout CON and BAL in all groups, whereas BF (P < 0.001) and ABF (P < 0.01) decreased in HP groups and lean body mass (LBM) and leptin increased in HP6. Following NEG, BW decreased in all groups. BF, ABF, and leptin decreased in HP groups; LBM remained higher (P < 0.05), and TEM was highest in HP6 (P < 0.05). 

CONCLUSIONS: Consuming increased protein (∼35%) more frequently (6×) throughout the day decreases BF and ABF, increases LBM and TEM, and favorably affects adipokines more than current recommendations for macronutrients consumed over three meals/day in overweight individuals during both BAL and NEG.