Once you understand that weight loss is about limiting fat storage, it’s clear why you have to limit carbohydrates in order to lose weight. Carbohydrates promote fat storage. The more carbohydrates you eat, the more fat you store. Stored fat is triglyceride. In order to make triglyceride (store fat), your body needs alpha glycerol phosphate, which comes from carbohydrates. The more carbohydrates you eat, the more alpha glycerol phosphate is available, so the more efficiently your body can store fat. When you don’t eat carbohydrates, fat storage is less efficient, because there’s less alpha glycerol phosphate around. Your body can still store fat without carbohydrate, but less efficiently, as your body has to use an alternate biochemical pathway.