"Test assumptions about protein quality with outcomes data The widespread belief that animal protein is superior to plant protein for building muscle is based on amino acid profiles and short-term absorption rates — but when researchers tested that hypothesis in controlled clinical trials, the assumption broke down. Hill describes studies where one group ate a fully plant-based diet and another ate an omnivorous diet, both doing the same resistance training for 10–12 weeks: 'we don't see any significant differences in terms of those outcomes of muscle size and muscle strength.' The theoretical advantage of animal protein's bioavailability, he explains, 'is not affecting those outcomes that we care about.' Anyone currently choosing animal protein primarily for its anabolic edge should reconsider that justification, since the real-world muscle and strength outcomes appear equivalent when total protein intake and resistance training are equated. Source: Simon Hill, Rich Roll Podcast, 2025 Dietary Guidelines Deep Dive"