Mixed
Soy protein supplementation produces identical increases in lean mass compared to whey protein in active individuals and athletes, making it an effective alternative for muscle growth.
If you are an athlete or active individual looking to build muscle, soy protein is just as effective as whey protein. You do not need to avoid soy for muscle gains. Ensure you are consuming enough total protein (at least 1.6 g/kg/day) and that your soy protein source is of high quality (high digestibility).
SP was found to provide identical increases in lean mass compared to whey in some studies.
Why this rating
Based on a systematic review of 19 RCTs, but the specific claim of 'identical' lean mass is noted as being from 'some studies' and the overall meta-analysis showed 'no significant difference' rather than superiority.
Source
Effect of Soy Protein Supplementation on Muscle Adaptations, Metabolic and Antioxidant Status, Hormonal Response, and Exercise Performance of Active Individuals and Athletes: A Systematic Review of Randomised Controlled Trials
Reza Zare et al. · Sports Medicine · 2023
DOI 10.1007/s40279-023-01899-w
More from this paper
- Soy protein supplementation reduces exercise-induced metabolic biomarkers such as triglycerides, uric acid, and lactate, and improves antioxidant status compared to whey protein in long-term studies.Good
- Soy protein supplementation improves exercise performance, particularly in high-intensity, high-speed, and endurance activities, by delaying fatigue and improving isometric strength.Good
- Soy protein supplementation has an inconsistent effect on testosterone and cortisol levels, and more research is required to determine its impact on anabolic hormones.Limited
Related findings · Mixed
- Bariatric surgery (VSG and RYGB) is the most effective and sustainable treatment for obesity, producing marked and sustained weight loss that non-surgical interventions cannot match.Strong
- Severely protein-deficient diets (2–3% energy) induce lean body mass loss and metabolic imbalance, whereas adequate protein intake (0.66 g/kg/d minimum) is a prerequisite for maintaining muscle, bone, and physiological function.Strong
- For patients with Class III obesity (BMI >39.9 kg/m2), metabolic bariatric surgery (MBS) is significantly more effective than any currently approved medication, with BilioPancreatic Diversion (BPD) showing the highest estimated weight loss.Strong
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →