Where does the fat go when you lose weight?

Most of us know a whole lot about fat. We know that the low-fat diet craze of the '90s is (thankfully) over and didn't do us any favors. We know trans fat is just plain bad news. And we even know fat around our middles is seriously unhealthy. But here's a stumper: When you manage to lose body fat, where the heck does it go? Here's the answer.

Fat cells (aka adipocytes), store excess energy from foods in the form of fatty acids called triglycerides.

As the triglycerides are stored within a cell, they force it to expand, increasing the cells diameter.

When you lose weight, your body converts fat to unstable energy for your muscles and other tissues, which causes the fat blobs in your fat cells to shrink.

If enough fat cells in an area of the body enlarge this way, that part of the body starts to look fat.

Source: Louis Aronne, obesity expert at New York-Presbyterian/Weill Cornell Medical Center