5000 calories. Because higher metabolic rate is correlated with increased longevity.
if you are a true hard gainer you already have a much higher than normal metabolic rate.. i have obviously seen slow metabolisms cause adverse health effects but never have I seen a study saying very overactive metabolisms correlate with increased longevity... actually pretty much the opposite in fact.. not to mention i couldn't afford to feed myself with 5k calories a day unless its pure junk