There is a lack of extensive research on protein intake and its effects on middle-aged adults due to logistical challenges.

“Middle-aged people, and I'll be the first person to admit this or probably not the first, we don't have a lot of data. And people ask why. And I'll give you a simple explanation. We can conduct lots of studies on university campuses as academic research institutions on young college-age people. There's lots of them around, willing participants in research. And we can conduct lots of research on people over the age of 65 as the meta-analysis, sort of implies. The people in the middle, they're busy people. They've got kids, jobs, lots of things going on. And we say, "Hey, you got to come into the lab for a whole day. You got to do this." And they're like, "I can't do that." So, they're not studied often.”