If an animal cell has excess energy, what is most likely to happen to this energy?
it will be considered waste.
it will be stored in high energy phosphate bonds.
it will be converted into starch.
it will be stored as fat molecules.

See body never utilizes full energy from the food. Our body utilizes only a certain amount of energy and the rest of the food is thrown out in form of faeces. So there is very little chance of having excess energy but if it happens then you will fall ill. Although the fat products are never directly converted into energy they are always stored in the form of fat molecules that's why Doctors always advices to do exercise or physical work if you take fatty diet.