Muscle and Fat both contain energy stores, but muscle is used first because it contains glycogen, the body's preferred fuel, amino acids, vitamins, minerals and water. Fat, on the other hand, has minimal water, no amino acids, vitamins, minerals or glycogen. So, if you neglect to nourish yourself, your body will get the nutrients it needs without your approval, even though you hope it chooses fat for fuel.
Complex carbohydrates are potatoes, brown rice, oatmeal and high grain pasta.
Fibrous carbohydrates are fruits and veggies. Eating this way will maintain steady energy levels and supply your body with a regular store of amino acids and glucose, which support lean muscle tissue. The fiber provides vitamins, minerals and helps with elimination. Just 20 minutes immediately upon rising and before eating breakfast is very effective. More than exercising for an hour later in the day.