Do you know that fat and thin people have actually the same number of fat cells? Yes, we have. The only difference is in the amount of fat stored inside the cells. So if somebody is fat, their fat cells appear bigger because of the greater amount of fat stored inside.
We also have two kinds of fat cells: those that store fat as a single large fat droplet and those that store fat as several small droplets. The first cells are called unilocular fat cells and the latter are called multilocular fat cells. The unilocular cells form what we call as white adipose tissue while the multilocular ones are what forms the brown adipose tissue. We have more white than brown adipose tissue.