[kscaldef]

> At the true elite level Michael Phelps is fueled by 12,000 calorie a day diet, eating that much food just hard. Think 60 Twinkies a day plus a 3000 calorie diet.

Even at much less intense levels, it's challenging to eat as much as necessary to maintain weight if you have a healthy diet. When I was training 100 miles a week (not all that much for a serious cyclist) I ate around 3300 calories a day. If my diet included stuff like Big Macs and triple mochas with a muffin, that would be easy. But if you aren't in the habit of eating lots of processed and fast foods, it's actually quick a bit of work to eat that much.