If you listen to some self-proclaimed exercise experts on social media, they swear that working out on an empty stomach burns more fat. But it’s a common misconception that exercising in a fasted state improves performance or burns more calories, said Abby Langer, a dietitian in Toronto. “The research shows that in terms of gains, it doesn’t really make much of a difference,” she said. Does that mean you should load up on protein and carbs right before a workout? No, that’s not true either.