Protein, while important for skeletal and biochemical functions, is not a primary source of energy. The American diet is traditionally ample in its supply of protein, so as athletes we probably need not concern ourselves too much about it. Fats are an important energy source. The problem is that fats are about twice as dense in calories as carbohydrates. Fat can be defined as a sneaky little substance which happens to make most of what we eat taste a little better.
Carbohydrates are the major source of energy.
They consist of two types - simple and complex. The simple group is basically sugars. They are called simple because they are easily broken down by the digestive system and quickly put to use. Simple carbos keep the brain functioning properly, and provide an immediate energy boost to the body. Complex carbohydrates include starches found in pasta, rice and potatoes.