Scientific American presents Nutrition Diva by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies.

Nutrition Diva reader Thomas writes:
"Some people claim that the body can't absorb more than 20-30 grams of protein at a time. Others insist that your body utilizes all the protein you take in. Who is right? Is a post-workout shake with 50 grams of protein a waste?"

This idea that the body can only utilize a certain amount of protein at one sitting has become widely accepted nutrition lore.  But is there any validity to the claim? It all comes down to what exactly you mean by "utilizing" protein.

This notion about protein seems to have gotten started on body-building forums - and this may be the main source of some of the confusion. Body-builders are particularly interested in protein's ability to build and repair muscles.  And there does seem to be a limit to how much protein the body can use for muscle synthesis at a given time.  

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