Do obese people have more fat cells than thin people?

The difference between obese people and thin people isn't the number of fat cells; it's the size of them. You don't make more fat cells the fatter you get; you have the same number of fat cells you had as an adolescent. The only difference is that the fat globules within each cell increase as you store more fat. By the way, muscles work the same way; you don't make more muscle cells; the muscle cells get larger.

As adults, obese people do not have more fat cells than thin people, but their fat cells are larger. The same is true in reverse: When an obese or overweight person loses weight, the fat cells shrink. But the number of fat cells doesn't change, just their size. Large fat cells have been linked to some of the chronic health conditions related to obesity, such as diabetes.