Very few people require the amount of calories mentioned in this thread. 5-6kcal is truly high. In addition to possessing a freaky metabolism, you must be one active bee all day long to burn/require all that energy substrate.
The average 5' 10 medium bone structure fella would faire well on 2500-3kcals tops. (This includes 4-5 intense workout days/wk)
The only other time where caloric requirements shoot up substantially is when you're supplementing with GH (pure, high quality @ a relatively high dose 8ius+).
^ Combine the above with AAS and possibly thyroid meds and you can down on average 3-5k without gaining too much chubb.
From a health standpoint, hammering down piles of food for a life time, is not only time consuming and burdensome, but also unhealthy.