I'm successfully trading fat for muscle but I want to understand why. There are at least three philosophies, which seem to contradict each other, and I do sort of a hybrid of these three. I eat lean protiens, in small amounts, my first meal being a protein shake and banana, and watch my total calorie intake. Usually dinner is my biggest meal of the day. Often times anything goes. I also exercise, although only about 30 minutes a day, 3 times a week. I do heavy cardio on a crosstrainer machine. So why is it working? Is it:1. Calories out > calories in = fat loss2. Eating small meals and concentrating on lean protiens and low carbs = fat loss3. Counting total calories and avoiding fats = fat loss (the Weight Watcher's theorem, expressed in points)