Is This the Reason It's Hard to Lose Weight?
May 24, 2008
Scientists have discovered why overweight people find it so hard to lose weight; the difference in the number of fat cells between lean and obese people is established during childhood. Although overweight people replenish their fat cells at the same rate as thin ones, they have around twice as many fat cells total.
This means that the number of fat cells in a person remains the same, even after a successful diet.
Until now, it was not clear that adults could make new fat cells. Many believed that fat mass was increased solely by incorporating more fats into already existing fat cells. In fact, people constantly produce new fat cells.
Fat cells are replaced at the same rate that they die, about 10 percent every year. Obesity is determined by a combination of the number of fat cells and their size; they can grow or shrink as fat from food is deposited in them.