Hey Scott, have you ever read the Hacker's Diet by John Walker (co-author of AutoCAD)? I do the same thing with the moving average, and that's where I got it from. I'm a programmer/database type too, so that kind of numbers game makes me happy. I really think everyone should read the Hacker's Diet, not so much for nutritional advice (it's low-cal) but for its insights into the physiology of weight loss, gain, and maintenance. His concept of the body as a "Rubber Bag" really made sense to me and helped me stop stressing out about daily fluctuations like you've just had. If you've never read it, give it a look.

Interestingly, the author talks about being in a ketosis state as a result of a low-cal diet, and describes it right down to keto-breath. He's not saying that you should worry about getting into or being in ketosis like Atkins does, but he's not dogging the process either. I never really thought about low-cal people actually being in ketosis as well, but it makes some sense from a physical perspective. Since lipolysis is the state of burning bodily fat, and ketones are the metabolite of that fat, you're going to be spilling ketones whenever you are burning fat, regardless of how you're doing it. Has anyone else ever looked into ketosis and low-cal diets?