Body fat, or the more technical term adipocytes (adipo means fat and cyte means cell), is found in many places around the human body and mostly underneath your skin, what we call subcutaneous fat. There is also some on top of your kidneys, inside your liver, and a small amount in your muscle tissue, which we call visceral fat.
An adult male often tends to carry his body fat in his chest, abdomen, and buttocks. An adult female tends to carry her fat in the breasts, hips, waist, and buttocks.
The main role of body fat is to serve as a type of energy storage facility. Up until the mid-nineties, it was thought of strictly as a passive place for us to store energy for the hard times, the times when our ancestors’ hunt didn’t go well (or the weather was poor) and there wasn’t enough food available. This turned out to be incorrect and it does have other uses but it is exceedingly good at storing energy.
A single pound of fat contains roughly 3,500 calories of stored energy. Assuming you could burn 100% body fat as fuel, this is enough energy for a 150-pound person to trudge about 35 miles. And that is only one pound of fat and most of us have a lot more than that to spare.