Nutritional Interventions: Dietary Protein Needs and Influences on Skeletal Muscle of Older Adults.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing existing observational and experimental research without systematic search criteria or meta-analysis.
PubMed 37325954 · doi:10.1093/gerona/glad038
What was done
This narrative review synthesized research identified via PubMed examining how dietary protein quantity, quality, and meal patterning influence muscle size, quality, and function in older adults across resting, catabolic, anabolic, and diseased states.
What was found
Intakes below the RDA (<0.8 g/kg body weight/d) worsened age-related declines in muscle mass, quality, and function. Observational data linked protein intakes of 1.0 to 1.6 g/kg BW/d to superior muscle strength and function (favoring animal over plant protein for sarcopenia metrics). Randomized feeding trials showed intakes averaging ~1.3 g/kg BW/d had no measurable impact on lean mass or physical function in non-stressed baseline states, but positively preserved lean mass under catabolic (caloric restriction) or anabolic (resistance training) conditions. Precise numbers, effect sizes, and study counts were not reported in the abstract.
Why it matters
It clarifies that protein intake exceeding the current RDA provides functional advantages primarily when paired with exercise or during energy restriction, rather than in sedentary, weight-stable states.
Limits
As a narrative review, it lacks a systematic methodology, quality assessment of included studies, and quantitative meta-analysis. The abstract provides no exact sample sizes or statistical effect sizes, and observational findings are subject to residual confounding.
Cited by
- supports The Recommended Dietary Allowance (RDA) for daily protein intake is less than half of 1 gram per pound of body weight.