The Study
Long-term effects of plant vs. animal protein supplementation on body composition, muscle strength, physical performance, and cardiometabolic risk factors in adults:a systematic review and meta-analysis of randomized controlled trials
This study looked at lots of experiments where people were randomly given either plant or animal protein to see what happened over time. It found that, on average, both kinds of protein seemed to do about the same thing for muscles and health. But because the studies were different from each other and some might not have been fully reported, we can't be super sure.
Analysis score
Maximum 100 for a systematic review with meta-analysis.
Where the score came from
Scientists looked at 18 long-term studies where people took either soy protein (plant) or dairy protein (animal) for 6 months to over 2 years to see if one was better for muscle, strength, or health.
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
The highest quality evidence. Systematic reviews and meta-analyses that pool randomized controlled trials, giving the most reliable summary of experimental evidence.
Key takeaways
Summary
Based on the study abstract and findings.
- 1If you're getting enough protein daily, it doesn't seem to matter much if it comes from soy or dairy for muscle or heart health — but the studies aren't super reliable.
- 2Both groups gained similar muscle, lost similar fat, had similar strength, walking speed, and blood test results — no big differences found.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Nutrition
Year
2026
Authors
Mohammed Ahmed Yimam, Justin Roberts, Andrea O’Callaghan, A. Holwerda, Y. Cassidy, Y. Luiking, A. van Helvoort, M. Muscaritoli
Related Content
Claims (6)
Men who lift weights for 12 weeks and take either plant-based or animal-based protein supplements gain the same amount of muscle mass and strength.
In adults aged 18 and older, long-term use of plant-based protein from soy does not change levels of cholesterol, triglycerides, blood pressure, glucose, insulin, or insulin resistance compared to animal-based protein from dairy. In people aged 60 and older, triglyceride levels may be lower with plant-based protein, but this finding is not confirmed across the full group.
The current evidence does not reliably show that plant protein and animal protein have the same effect, because the studies used to compare them are inconsistent, possibly incomplete, and lack precision.
When adults consume adequate amounts of protein, replacing animal protein with plant protein from soy does not change lean body mass, fat mass, or total body weight over 6 to 31 months.
In adults aged 18 and older, long-term use of plant-based protein from soy does not produce different results in muscle strength, walking speed, or physical performance tests compared to animal-based protein from dairy.
Most studies comparing plant and animal protein supplements have only used soy and dairy, so it is not known whether results from these studies apply to other plant proteins like pea, rice, or hemp.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.