The Claim
In untrained young adults undergoing supervised resistance training three times per week for 12 weeks, daily consumption of either 19 grams of whey protein isolate or 26 grams of soy protein isolate—both delivering 2 grams of leucine—results in comparable increases in lean body mass, with no statistically significant differences between the protein sources, indicating that matching leucine content may equalize the anabolic response between these proteins.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
If you're a young adult just starting strength training, drinking a shake with either whey or soy protein—both with the same amount of a key muscle-building amino acid (leucine)—will help you gain muscle equally well over 12 weeks.
See the scientific wording
In untrained young adults performing supervised resistance training 3 times per week for 12 weeks, consuming either 19 grams of whey protein isolate or 26 grams of soy protein isolate—both providing 2 grams of leucine daily—results in comparable increases in lean body mass, with no statistically significant differences between protein sources, suggesting leucine matching may equalize anabolic responses.
What the research says
1 studyThe study found that young adults gained similar muscle and strength on soy or whey protein when both had the same amount of leucine, so the results support the idea that the type of protein doesn’t matter as much when leucine is matched.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.