The Study
Muscle strength gains during resistance exercise training are attenuated with soy compared with dairy or usual protein intake in older adults: A randomized controlled trial.
This study gave different protein diets to older people who lifted weights and found that those who ate soy didn't get as strong as those who ate dairy or ate their normal amount. But we can't be 100% sure because we don't know if the people or researchers knew who got which diet.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Older adults who drank soy protein shakes while lifting weights didn't get as strong as those who drank dairy shakes or ate their normal diet.
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 551 / 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.
- 1Yes — a 30% difference in strength gain is large and likely meaningful for daily function in older adults.
- 2Soy group: +63% strength gain; Dairy group: +92%; Usual diet group: +92%.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Clinical nutrition
Year
2016
Authors
R. Thomson, G. Brinkworth, M. Noakes, J. Buckley
Related Content
Claims (4)
Resistance training increases the effectiveness of dietary protein in preserving muscle mass and supporting physical function.
People who consume about 1.3 grams of protein per kilogram of body weight and include dairy while eating fewer calories maintain their strength levels.
Among healthy older adults doing 12 weeks of resistance training, consuming more than 1.2 grams of protein per kilogram of body weight daily from dairy or soy increases total protein intake compared to lower intake, but does not change lean mass, physical function, or mental health.
In older adults doing resistance training for 12 weeks, consuming soy protein leads to smaller increases in muscle strength than consuming dairy protein or their usual protein intake.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.