I agree with Wooo. Our bodies are amazing at adapting to all sorts of conditions. Although we may not understand all of the mechanisms, it is clear that we can adapt to certain diets with metabolic and enzymatic changes.

Carb cycling didn't work for me personally, because once I up my carbs it triggers cravings and I have a hard time getting back on plan. But if you can do it, I think it works.

Studies have shown that most people on low carb do eat less calories than they used to, even if they're not trying to. So an occasional cheat day should counteract the metabolic drop from eating less calories.