The Study
The effects of dietary protein intake on appendicular lean mass and muscle function in elderly men: a 10-wk randomized controlled trial.
This study gave two groups of older men different amounts of protein and saw what happened to their muscles. Because they randomly picked who got which diet, we can guess that the protein made the difference—not something else. But we can't be 100% sure because not everyone was blinded.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Older men who ate twice as much protein as the usual recommendation kept more muscle and got stronger legs, while those who ate the usual amount lost muscle—even when both groups ate the same number of calories.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 566 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Losing 0.64 kg of muscle in 10 weeks can make walking or standing harder for an older person; gaining muscle and power improves daily movement and reduces fall risk.
- 2Men eating 1.6 g/kg/day gained 1.49 kg of total muscle and 1.39 kg of trunk muscle, and improved leg power by 26.6 watts.
- 3Men eating 0.8 g/kg/day lost 0.64 kg of arm and leg muscle.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The American journal of clinical nutrition
Year
2017
Authors
C. Mitchell, A. Milan, S. Mitchell, Nina Zeng, F. Ramzan, Pankaja Sharma, S. Knowles, N. Roy, A. Sjödin, K. Wagner, D. Cameron-Smith
Related Content
Claims (6)
For adults over 65, clinical guidelines state that daily protein intake should be 1.2 to 1.6 grams per kilogram of body weight, spread evenly across meals, with additional focus on consuming protein before sleep.
Among men over 70, consuming 1.6 grams of protein per kilogram of body weight daily for 10 weeks leads to 1.39 kilograms more trunk lean mass gain than consuming 0.8 grams per kilogram daily, even when both groups are in a moderate calorie deficit.
Elderly men over 70 who consume 0.8 grams of protein per kilogram of body weight daily for 10 weeks lose an average of 0.64 kilograms of muscle in their arms and legs.
Among healthy men over 70, eating 1.6 grams of protein per kilogram of body weight daily for 10 weeks increases whole-body lean mass by 1.49 kg, arm and leg lean mass by 0.75 kg, and knee-extension power by 38.3 watts compared to eating 0.8 grams per kilogram per day, regardless of total calorie intake.
Elderly men over 70 who consume 1.6 grams of protein per kilogram of body weight daily for 10 weeks gain about 26.6 watts of peak power in knee extension, while those consuming 0.8 grams per kilogram per day show no significant change, regardless of total calorie intake.
In men over 70, consuming 1.6 grams of protein per kilogram of body weight daily leads to greater increases in lean mass and leg power compared to lower intake, even when both groups are in the same state of moderate energy deficit.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.