If you regularly exercise without eating first, you should reconsider: when you work out on an empty stomach, research shows that the calories burned come from muscle, not fat. Since muscle burns more calories than fat, the more muscle mass you have, the better it is for weight loss. Not only will fuelling your body help you avoid losing muscle, but also, you'll have more energy to push yourself through your workout.
Image Source: POPSUGAR Photography / Rima Brindamour