3. Caffeine: Coffee is good for more than just a jolt in the morning. A study in the International Journal of Sport Nutrition and Exercise Metabolism found that consuming caffeine an hour before you hit the gym can help you burn about 15 percent more calories than normal. What’s more, other research has found that sipping on the stimulant before the gym can help you eat fewer calories afterward.
Fat metabolism is the most efficient way to produce energy, allowing you to go and go and go without burning through a ton of calories. But efficiency is the enemy of fat loss. To lose body fat, you want to churn through calories—calories from carbs, calories from fat, calories from anything—and you get there through carb metabolism. “The more energy-demanding the work, the more likely you are to lose body fat,” Zimmerman explains.