Bob....what you are proposing doing is not "some sort of diet"...it's a path to self-destruction and will do nothing to deal with the root of your problem, which is controlling your eating habits. If you cut your calories that low, your body will go into starvation mode, shut down your metabolism and then when you get to your goal (assuming you don't give up from hunger and feeling sick or wind up in the hospital first) and go back to eating "normally", the weight will pile back on because you have reset your metabolism to a lower level than before. Trainerdan is right. This will not fix your problem...it will give you a whole NEW set of problems to deal with on top of the one that you already have. You said that you can't control your bad eating habits unless you are on some sort of diet. If that's true, then you didn't learn anything the last time around and starving yourself is not a diet...it's called anorexia. Now is the time to change that. You are treating this as a short term solution to a long term problem. Controlling your eating habits isn't something that you do for a while until you loose the weight that you need to loose and then quit (as you've already discovered, I hope, but maybe not); it's something that you do for LIFE. 170 is not an unreasonable weight for an adult male of average height and body frame. Why the obsession with being a size small? You said you have a gut to loose? Try cruches. Then again...if you're eating 500 calories a day, don't try crunches...you won't be able to build any muscle anyway, so it will just be wasted energy and you won't have a lot to waste eating like that.