"When you take carbohydrate before a workout, you alter the metabolism and shift from a process called autophagy, which is self-eating. When you workout hungry, your cells actually consume the damaged proteins inside your cells and recycle them into fresh new structures. Every workout tears muscle protein, tears actin and myosin. So what's going to happen to those damaged tissues?"
"Well, they're going to be degraded by autophagy, this process of internal consumption of damaged proteins and be recycled as fresh proteins. So you're making new healthy cell tissue at a much higher rate if you train hungry. The minute you have any carbohydrate before you go workout, you're not going to burn fat now. You're also going to completely shut down autophagy, because it only operates when insulin is virtually zero." - Art De Vany, economics professor and nutrition expert