Carbohydrate consumption is not necessary to stimulate muscle protein synthesis (MPS) or to promote muscle gain, as proteins have an insulinogenic effect, albeit a much smaller one, and insulin plays a permissive rather than a driving role in this process.

noli's read

Stuart Phillips relies here on metabolic biochemistry research (referenced via Don Layman) concerning the role of insulin. It is established by research, including meta-analyses and randomized controlled trials (RCTs), that insulin is indeed 'permissive': its presence is necessary to limit protein degradation, but it does not directly stimulate muscle protein synthesis beyond a low threshold (Journal of Physiology). The advice is scientifically robust on a mechanistic level: protein ingestion triggers an insulin response sufficient to maximize MPS, making the addition of carbohydrates superfluous for this specific objective. The potential exaggeration lies in the interpretation: while carbohydrates are not 'necessary' for synthesis, they remain crucial for high-intensity performance and glycogen resynthesis, which are essential indirect factors for long-term muscle growth. The creator is focusing here strictly on the molecular mechanism of MPS, where his assertion is supported by current data.

the sources

No named source held this one up — that absence is part of the verdict.