That's because muscle serves as a primary energy consumer for your body. Think of it as a raging fire. Toss a log into it and it'll burn it up pretty quickly. But your fat is more like one lit match—it would take years for that match to burn the log. In your body, muscle can fry up that cheese dog a lot faster than your fat—thus reducing the amount of fat you store. Add just a little more muscle and you'll use more energy and store less fat. And that makes it an even more efficient exercise for burning fat than cardiovascular training.
While muscles give us the metabolic ability to burn calories every time we move—during exercise, during gardening, during sex—their true advantage is that they constantly feed on calories, even when you're moving about as fast as a skateboard with a busted wheel. See, every pound of muscle burns between 50 and 150 calories a day just to sustain itself, while every pound of fat only feeds on 1 to 3 calories. Day after day, that's a huge difference in your metabolic rate and your daily calorie burn. When you add a water bottle full of muscle to your body, you're able to burn a refrigerator full of fat.
Find out more about this book:YOU: On A Diet Revised Edition: The Owner's Manual for Waist Management