How much dietary protein can be assimilated at once?

I get this question a lot. It's a good question.

Need =/= optimization.

30 grams works. Is 50 better? By how much?

You can still get a smidge more protein synthesis up to 70 grams in a meal (that’s as high as has been tested; so it could theoretically be higher). However, there is an inflection curve around 40-50 grams or so. Beyond that, you still get modestly more protein synthesis, but you start to enter the realm of amino acid oxidation. That's not a bad thing per se, but protein is the most expensive macronutrient so it starts to become a waste of money. And I'd rather be oxidizing fats & carbs than amino acids. So I'd say 50 is fine, but don't go too much higher (per meal).

Time between meals also matters. There is a refractory period when if you have another protein-rich meal too soon after your first one, you get less bang for your buck. The precise duration hasn't been worked out to my knowledge, but I try to leave 3-4 hours (preferably as much as 6 hours) between meals. 

Personally, I like 3 meals a day: 6 am, 12 pm, and 6 pm. Since my target is 150 g/d, I try to get as close to 50 grams per meal as possible. 

*I use the terms muscle protein synthesis and inhibition of muscle proteolysis or catabolism kinda interchangeably with the intention to signify net muscle protein accumulation (either via synthesis or inhibition of breakdown). With adequate resistance training, we can hope this is functional muscle proteins leading to gains in strength and hypertrophy.

That’s all for now! Thoughts?