Per meal dose and frequency of protein consumption is associated with lean mass and muscle performance.
Level 4 - case-series / case-control
Cross-sectional analysis of NHANES survey data
PubMed 27086196 · doi:10.1016/j.clnu.2016.04.002
What was done
Researchers evaluated data from 1,081 adults aged 50 to 85 years in the 1999–2002 National Health and Nutrition Examination Survey (NHANES). Dietary intake was collected using a multiple-pass 24-hour recall to determine the frequency of consuming meals containing at least 30 g of protein. Leg lean mass was measured using whole-body dual-energy X-ray absorptiometry (DXA), and muscle performance was measured as knee extensor strength using an isokinetic dynamometer.
What was found
Compared with 0 meals of ≥30 g protein, consuming 1 meal was associated with greater knee extensor strength (adjusted β = 23.6, p = 0.002) and leg lean mass (adjusted β = 1160, p < 0.05). Consuming 2 meals of ≥30 g protein was associated with greater strength (adjusted β = 51.1, p = 0.001) and leg lean mass (adjusted β = 2389, p < 0.05). The association plateaued at approximately 30 g/meal for those eating 1 high-protein meal and at ~45 g/meal for those eating 2 high-protein meals. Leg lean mass mediated 64% of the total relationship between protein meal frequency and strength.
Why it matters
This study provides population-level observational evidence that consuming 1 to 2 meals per day with 30 to 45 g of protein per meal is associated with better preserved lean mass and muscular strength in older adults.
Limits
The cross-sectional design cannot establish causality. Dietary intake was captured by a single 24-hour recall, which may not reflect long-term habitual intake and is subject to recall errors. Unmeasured confounders may also influence the observed associations.
Cited by
- supports Older adults require at least 25 to 40 grams of protein per meal to reach the threshold that stimulates muscle protein synthesis.