Way back, I used to eat a dozen eggs and 2 chickens per day….along with peanut butter, protein shakes, and rice. Crazy thinking about it now.Per dollar, a gallon of whole milk a day is the most efficient way to get adequate calories for building muscle. I dont know if I could do all that.
A guy I know who lives way up North eats about 5,000 calories per day in winter just to maintain his weight doing chores outside (brutal environment).

