The Study
Effect of a protein intervention during resistance training with varying training intensities on muscle outcomes in frail community-dwelling older adults: a randomized controlled trial
This study is like a fair test where half the people got extra protein and half didn’t, and then we saw who got stronger. It tells us that, on average, the extra protein didn’t help much—but it might help a few people who weren’t eating enough protein to begin with. We can’t say for sure it helps those people yet, because the group was too small.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Older adults who are frail and weak did resistance training twice a week. Some got protein shakes and diet advice to eat more protein, others didn't.
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 590 / 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.
- 1For frail older adults who barely eat enough protein, adding shakes and advice might help them get noticeably stronger in their legs — which helps with standing up and walking.
- 2But for most, just doing the training is enough.
- 3Everyone got stronger from training.
- 4The protein shakes helped people eat more protein, but didn't make most people stronger overall.
- 5Only those who ate very little protein before (less than 0.8g per kg of body weight) got much stronger with the shakes — about 11 kg more in leg press.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of Nutrition, Health & Aging
Year
2026
Authors
E. Biersteker, M. Benali, Jantine van den Helder, J. Twisk, M. Tieland, P. J. Weijs, J. Schoufour
Related Content
Claims (7)
Resistance training increases the effectiveness of dietary protein in preserving muscle mass and supporting physical function.
Among older adults aged 65 and older who are frail and live in the community, adding protein supplements to a 12-week supervised resistance training program does not result in greater improvements in leg strength, muscle mass in the arms and legs, or physical performance than resistance training alone.
Frail older adults who lift weights to muscle failure, whether using light or heavy weights, gain the same amount of strength in their legs.
In frail older adults, taking protein supplements while doing strength training does not lead to measurable improvements in muscle size, grip strength, walking speed, or the ability to stand up from a chair, even if their usual protein intake is low.
In frail older adults who consume less than 0.8 grams of protein per kilogram of body weight daily, adding protein supplements to resistance training resulted in a 10.9 kg greater increase in leg press strength than resistance training alone over 12 weeks.
In frail older adults, a 12-week program of whey protein supplements and dietary counseling increased daily protein intake by 0.4 grams per kilogram of body weight.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.