The amount of protein per meal needed to trigger muscle protein synthesis might be related to blood volume, not body weight.

“One of the things that I talked about with Gabrielle Lian recently is that that number might be more dependent on blood volume than overall weight she was talking to Don layman about that so I thought that was interesting that even for smaller individuals that still that number might be similar because even our individuals we don't have as much variation in our blood volume between us you know you and I might have both have a similar blood volume even though you're a bigger human so even smaller individuals might need that large amount and larger individuals might still get muscle protein synthesis at a 2.6 ish gram leucine threshold”