Have you ever stood before the mirror and looked at the pudge on your body and wondered why our bodies tend to store fat in the first place? Why not build more muscle, for example? Why do we tend to build up fat around our arms, bellies, thighs, hips and back? What is the purpose of this fat, and why did we evolve to store it as we do? Why is it so hard to burn fat off, and easy to lose muscle? These questions are so basic that we often don’t even think to ask them, but there is a biological answer to each one. In today’s article we’re going to take a look at why our bodies seem to love fat and what purpose it serves, and why we tend to store it and have so much difficulty burning it when we want to lose weight. If you’ve ever wondered about any of these questions, read on!
First, let’s take a look at what fat is and what it’s for. Known as adipose tissue, it’s almost ninety percent lipids and about ten percent water and other cellular mechanisms. Each little fat cell is thus basically three chains of triglycerides attached to a glucose molecule, and has very little water in it. A pound of fat is thus very dense in lipids and relatively light in water, and packs about 3,600 calories of energy into it. Thus to burn off a pound of fat, you need to burn 3,600 calories of just pure fat.
On the other hand, carbohydrates stored as energy as glycogen in your liver and muscles is full of water, and thus makes it less concentrated and dense a form of energy. For every gram of glycogen stored, you need about three to four grams of water. Thus you simply can’t store that much energy because the volumen needed to match what fat can do is huge. Fat is therefor a very efficient way to store energy merely in terms of space.
But it goes beyond simple volume: one gram of fat provides about nine calories of energy, while one gram of carbs or protein usually provides only about four calories. There is such a huge difference here that we can easily see why our bodies love to store energy as fat and not anything else.
Yet why is it so hard to burn? Because fat serves us as our emergency store of energy, and so our bodies tend to turn to it last when we diet.