As long as there is energy left to burn in your glycogen stores, your body never start burning fat. However, when these glycogen stores get low, your body does two things:
First, it’s going to throw a tantrum. While there may be plenty of fat in your reserves, your body doesn’t burn it right away. Instead it begs and pleads with you to find some candy, a yogurt, potato chips, something, anything with carbs.
This is why you have sugar cravings. Your body has forgotten how to effectively burn fat for energy. And if you continue to surrender to these cravings, you will never burn fat.
But, sugar cravings are actually a good thing. They’re a signal that your body is about to start burning fat, but only if… you’re stronger than the tantrum.
