Most people ask why low carbs? When you eat carbohydrates it raises your glucose level in the blood. This thus causes your body to discharge insulin. It is insulin's job to get that s glucose out of the circulatory (blood) system and into your cells. Initially it tries placing glucose into muscles and when the muscle is filled with glucose, insulin pumps the remaining glucose into fat cells. While the insulin is doing its work your body will burn the glucose in your circulatory system first before attempting to burn your fat. Thus, if you can keep the glucose level low in the circulatory system, insulin won't put that glucose in your fat cells and the body has small glucose in the circulatory system to use for vitality. Accordingly, the body must utilize something else, like fat, to burn for vitality (energy).