Bama, the way you're eating will make you physically even sicker. Maybe you'll have lost weight, but it is totally screwing up your metabolism and so the weight loss won't be permanent. I can't claim to understand how meth affects your motivation, but if you can swing this, then eat regular meals and get some exercise. Even if it means just going for a walk for an hour... exercise and regular meals are going to get you to lose the weight permanently.

Just don't mess with your metabolism. It's a recipe for physical disaster.