Are We Born with All of the Fat Cells We Will Ever Have?

We are not born with a full complement of fat cells as some scientists once thought. The number of fat cells in the body increases at various stages throughout growth, but by the time adulthood is reached the total number of these cells can become fixed. This means that if our body fat mass does not change, we probably would not produce new fat cells as adults. However, if we consume excessive calories, the number of fat cells can increase. In adipose tissue there is a small number of so-called pre-adipocytes or fat stem cells. When these cells are signaled, they will produce new fat cells. As you may have guessed, the signals are chemicals, many of which are released by existing fat cells when they become swollen with an increased bounty of stored fat.