Summary
Highlights
Alan Aragon introduces his definition of protein quality, emphasizing the type and ratios of amino acids and their availability relative to the caloric intake required. He highlights a common misconception about plant-based foods often requiring a much higher caloric intake to achieve an equivalent amino acid profile compared to animal proteins.
Aragon states that, gram for gram, animal proteins are generally of higher quality, possessing more anabolic properties due to a greater proportion of essential amino acids, particularly branched-chain amino acids like leucine. He notes that studies comparing animal and plant proteins typically show greater muscle protein synthesis with animal proteins in the short term.
The discussion shifts to longitudinal studies comparing completely vegan regimens with omnivore diets, specifically with resistance training. A 12-week study by Lraine and colleagues, which maintained isocaloric and isomacinutrient intake, found no significant differences in muscle size and strength gains between vegans (supplemented with soy protein to reach 1.6g/kg body weight daily) and omnivores. This suggests that with proper construction and supplementation, a vegan diet can support muscle growth comparable to an omnivore diet for untrained individuals.
Despite the vegan diet groups having significantly less essential and branched-chain amino acid content, the resistance training stimulus appeared robust enough to make the protein source almost secondary in these studies. This underscores exercise as a primary driver of muscle adaptation, followed by sleep as another critical factor.
A later study by Montene and colleagues replicated these findings using a fungus-based protein (mycoprotein, commercially known as Quorn) to boost the protein intake of the vegan group. Again, no significant differences in muscle size and strength increases were observed compared to omnivores over 12 weeks. Mycoprotein also showed promising anabolic effects, outperforming milk protein in an acute muscle protein synthesis study.
Huberman raises the important factor of satiety, noting that it wasn't measured in the discussed studies, which could impact the long-term adherence to a diet. Aragon highlights that these studies mostly involved untrained subjects, whose 'newbie gains' from resistance training might mask any subtle advantages of specific protein types. He emphasizes the need for more research on highly trained individuals to definitively determine if a completely plant-based, calorically and protein-optimized regimen can truly match high-quality animal-based proteins in elite performance settings.