The Study
Similar effects between animal-based and plant-based protein blend as complementary dietary protein on muscle adaptations to resistance training: findings from a randomized clinical trial
This study is like a fair race between two types of protein shakes to see which one helps people get stronger and build more muscle. It found both shakes worked about the same. But it only tested young men who already ate meat — so we don’t know if it works the same for girls, older people, or vegans.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave young men either plant protein (soy + pea) or whey protein while they lifted weights for 12 weeks to see which made them stronger and more muscular.
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 568 / 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 — gaining 2.4 kg of muscle and 64 kg more strength in 12 weeks is a meaningful, real-world improvement for someone starting resistance training.
- 2Both groups gained about 2.4 kg of muscle, increased leg muscle size by nearly 1 cm², and got 64 kg stronger on the leg press — no difference between plant and whey.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of the International Society of Sports Nutrition
Year
2025
Authors
Martin Hindermann Santini, Alice Erwig Leitão, B. Mazzolani, F. Smaira, Mariana Silva Camargo de Souza, A. Santamaria, Bruno Gualano, Hamilton Roschel
Related Content
Claims (6)
Healthy adults should consume 1.2 to 1.6 grams of protein per kilogram of body weight. People who do resistance training should aim for up to 1 gram of protein per pound of body weight.
Among healthy young men doing supervised weight training and consuming 45 grams of protein daily, a combination of soy and pea protein results in the same increases in muscle mass, muscle size, and lower-body strength as whey protein.
Healthy young men who consume 45 grams of soy and pea protein daily in three meals while doing resistance training for 12 weeks gain 2.4 kilograms of lean body mass and increase the size of their thigh muscle by 0.9 square centimeters.
In healthy young men performing resistance training, consuming 1.6 grams of plant-based protein per kilogram of body weight per day in three meals produces the same increase in leg press strength as consuming the same amount of whey protein.
A mixture of soy and pea protein stimulates muscle growth during resistance training in healthy young men to the same extent as whey protein.
In healthy young men doing resistance training and eating a regular diet, taking 45 grams of soy and pea protein daily for 12 weeks leads to the same amount of fat loss as taking 45 grams of whey protein.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.