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

Obesity (Silver Spring). 2013 Jul;21(7):1357-66. doi: 10.1002/oby.20296. Epub 2013 May 23.

Abstract

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.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdominal Fat / metabolism*
  • Adult
  • Blood Glucose / metabolism
  • Body Composition
  • Body Fat Distribution
  • Body Weight
  • Dietary Carbohydrates / administration & dosage
  • Dietary Fats / administration & dosage
  • Dietary Proteins / administration & dosage*
  • Energy Intake*
  • Energy Metabolism*
  • Fasting
  • Humans
  • Hunger / physiology
  • Insulin / blood
  • Leptin / blood
  • Meals*
  • Middle Aged
  • Obesity / metabolism
  • Overweight / metabolism
  • Patient Compliance
  • Postprandial Period / physiology
  • Satiation / physiology
  • Thermogenesis / physiology

Substances

  • Blood Glucose
  • Dietary Carbohydrates
  • Dietary Fats
  • Dietary Proteins
  • Insulin
  • Leptin