Ever read Atkins?
Because something is high in calories does not mean it is absorbed well into the body. You statement is way over simplified.
While I've know some people to have excellent results with this diet, I don't think it's for kids. I also can't handle it.
I think the underlying notion of increasing protein while limiting heavy carbs is a good one, though I'd also watch the fat.
Adding a small serving of carbs with a little drizzle of olive oil can really add to one's sense of satiety, and that can help avoid the munchies.