About half of the adults in the United States are overweight. That's 97 million people who have too much fat. Many Americans exercise and go on diets to reduce their amount of body fat.

But have you ever wondered what fat is? When a person "gets fat" -- gains weight -- what is actually happening inside the person's body? What are "fat cells" and how do they work?

In this edition of How Stuff Works, we will look at the world of the fat cell. We will examine where fat cells are located, how they store fat and how they get rid of it!