Scientific Abstract
Background
Emerging research suggests that re-distributing total protein intake from one high-protein meal daily, to multiple moderately-high protein meals, improves 24 h muscle protein synthesis. Over-time, this may promote positive changes in body composition and indices of cardio-metabolic health.
Objective
We sought to assess the effects of within-day protein intake distribution on dietary energy restriction and resistance training-induced changes in body composition and clinical cardio-metabolic health indicators.
Design
In a randomized, parallel-design study, 41 men and women (mean ± SEM; age: 35 ± 2 y; BMI: 31.5 ± 0.5 kg/m2) consumed an energy-restricted diet (750 kcal/d below requirement) for 16 wk while performing resistance training 3 d/wk. Subjects consumed 90 g protein/d (1.0 ± 0.03 g•kg-1•d-1, 125% of the recommended dietary allowance, at intervention week 1) in either a skewed (10 g breakfast, 20 g lunch, 60 g dinner; n=20) or even (30 g breakfast, lunch, and dinner; n=21) distribution pattern. Body composition and cardio-metabolic health indices were measured pre- and post-intervention.
Results
Over time, body mass (-7.9 ± 0.6 kg, LSmean ± SE), lean mass (-1.0 ± 0.2 kg), fat mass (-6.9 ± 0.5 kg), serum glucose (-2.9 ± 1.2 mg/dL), HOMA-IR (-1.3 ± 0.2), total cholesterol (-21 ± 4 mg/dL), and triglycerides (-26 ± 7 mg/dL) each decreased. Mid-thigh muscle area (cm2) did not change over time. Within-day protein distribution did not differentially affect these body composition and cardio-metabolic health index responses.
Conclusions
The effectiveness of dietary energy-restriction combined with resistance training to improve body composition, including fat loss and muscle retention, and clinical indices of cardio-metabolic health is not influenced by the within-day distribution of protein when adequate total protein is consumed.
Publications:
National Library of Medicine: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142737/
Nutrients: https://www.mdpi.com/2072-6643/8/2/63
