Protein supplies your muscles with amino acids for repair and growth. If your nutritional intake of protein, carbohydrate, and fat is correct for your activity level, then almost all of the nutrients will be put to use by your body. If your caloric intake exceeds your nutritional needs your body will have to do something with the excess. It eliminates some of the unnecessary calories. This puts undue stress on your digestive system and can lead to a premature breakdown of the organs involved.
Most people find themselves growing over-fat.
Usually the amount of fat cells you are conceived with are not enough to lead to obesity. It is during the third trimester, the first two years after birth, and again during the post puberty period that the predisposition to obesity takes place. The number of fat cells in your body can be increased by a high fat diet at these times. Once you acquire a large amount of fat cells they never go away. They enlarge when you store fat and they shrink when you reduce it.