What is the difference between structural, normal, and abnormal fat?

Structural fat fills the gaps between various body structures and acts as a sort of packing material for delicate organs like the kidneys and coronary arteries. It also keeps the skin smooth and taut, as well as providing the springy cushion of hard fat under the bones of the feet, which is necessary for walking.

Normal fat is a freely available fuel that is deposited all over the body. Both structural and normal fat, even at full capacity, cannot produce obesity.

Abnormal fat is the accumulation of fat that an overweight person carries and is deposited all over the body, though it mostly accumulates on the hips, buttocks, abdomen, upper arms, and thighs. Although it is a potential fuel reserve, it is not available to the body in a nutritional emergency until the body has first depleted its structural and normal fat stores.