Physiologists tell us that approximately 3500 calories equal on pound of fat it doesn't matter what type of food is eaten-nutritious food or junk it all contains calories and they all count so it 100 calories remains unburned at the end of each day for 35 days the body will gain one pound of fat by the end of this year the body will have gained 10 pounds at the Rste this is the cumulative nature of weight gain