> I had a friend who would drink a gallon of whole milk a day to maintain weight because he did so much at the gym. That honestly might be an absorption issue,

> I had a friend who would drink a gallon of whole milk a day to maintain weight because he did so much at the gym. That honestly might be an absorption issue, not an intake issue - you can hit aerobic limits enough for your body to skip digesting stuff & just shove protein directly out of the stomach instead of bothering to break it down. My experience with this was a brief high altitude climb above 5km in the sky, where eating eggs & ramen stopped working and only glucon-d kept me out of it. The way I like to think of it is that the fat in your body can be eaten or drank, but needs to be breathed out as CO2 to leave it. The rate at which you can put it in and the rate of letting it go are completely different.