you don't eat all the time but need energy all the time which you get almost all of from the carbs and fats that you eat and protein if you run out of carbs and fats
Storing
you store a bit of carbs and quite a bit of fat and these energy stores provide you with energy whenever you need it.
Short-term Energy Stores
you store a small amount of carbs in your cells, especially in the liver and muscles.
Long-term Stores
your body stores fat in special cells underneath the skin and around some of the body organs.
Heat Insulation
Fat stored in the body also heat insulation. eg: animals in cold places have a lot of fat stores underneath their skin to prevent heat conduction (the loss of heat)
