I am an athletic 6'0 male who has gone from 280 to 215 in three months (20 pounds the first two months each, then 25 this past month). My method has been to eat very little food (500 [five hundred] calories per day) and exercise a lot.

Typically I'll eat breakfast and dinner each day, choosing between skinless chicken breast, rice, lentil chili, and a couple chicken-based Indian dishes that are basically a bunch of fresh veggies (i.e. nothing pre-made or from a can). I drink 8-10 glasses of water spread out through the day. Sometimes I'll have a banana, orange, or a few hard-boiled egg whites for a snack. I do ~40 minutes cardio five times a week and lift weights about three times a week.

This has gone remarkably well so far.

But lately I've been reading that eating too few calories can hurt you by making your body think it needs to hold on to every last bit that it can. That makes sense, but how is it that I've managed to keep up my pace by eating so little? Am I suddenly going to hit a brick wall and just stop losing weight?

If I do need to increase my caloric intake, is it still possible to continue losing 20 pounds a month? My goal is to reach 160-180 (I'll decide when I get there, not sure what a 'normal' weight for my frame would be) and I'm almost there so I'd hate to change my routine which has worked very well so far.

Also, is it a viable strategy to have a cheat day once a week to keep my metabolism from slowing? For example, going hog wild every Saturday and eating what I used to eat before I dieted.