How does the body react to an increased energy intake?
If more energy is supplied than is needed to generate heat, the surplus ends up in the fat stores. According to the first law of thermodynamics, fat is stored as long as there is a constant oversupply until a new equilibrium is achieved by increasing the surface of the skin and thus the calorie requirement. A theoretical requirement of 2500kcal with an actual intake of 3000kcal would mean that the skin surface has to increase by 20%.