Muscle protein synthesis window — September 2026

Dr.KarenChen said:

The RDA is the wrong reference and it is worth understanding why.

I will push back on the powder-first advice. It works and it also trains people out of eating food, and when the drug stops the habits are what remain. Getting protein from meals is slower and holds up better afterwards.

One concrete data point for the thread. If you are tracking this properly: same scanner, same time of day, same hydration, at least six months apart, and read grip strength or a lift number alongside it. Function is the outcome; the scan is the proxy.

Worth separating that from lean-mass preservation, which this thread keeps folding into the same question. They behave differently and the advice does not transfer.

NeuroNate said:

I will push back on the powder-first advice.

Coming at NeuroNate’s question from a different direction. There is also a quality change that the scan cannot see. Weight loss shifts fiber-type distribution toward Type I and improves mitochondrial density and insulin-stimulated glucose uptake per fiber — so the muscle you keep is metabolically better even though there is less of it. That does not make the loss irrelevant, but it explains why function often holds up better than the number suggests.

One thing that is still open after SkepticalSean’s answer:

Whether the RDA is the wrong reference entirely during rapid weight loss, and what the actual target should be?

Closing the loop on my own question.

Update: two thirds of the target before midday. Same total, same appetite, and I am hitting it most days now.