Obesity: Your number of fat cells stays constant in adulthood

number of fat cells, or adipocytes, in your body remains more or less constant throughout adulthood, a new study finds। The discovery suggests that the difference in the number of fat cells between lean and obese people is established in childhood, and then persists for life।The number of fat cells remains constant even in formerly obese adults who have lost significant amounts of weight, report researchers led by Kirsty Spalding, who studied fat samples from liposuction and abdominal reconstruction surgery in lean and obese volunteers। This reflects the fact that the level of obesity is determined by a combination of the number and size of fat cells, which can grow or shrink as fat from food is deposited in them।Although fat cell numbers remain constant during adulthood, this is a dynamic process of death and replenishment, Spalding and her colleagues report. Fat cells are replaced at the same rate that they die — roughly 10% every year. The researchers made their discovery by studying levels of radioactive isotopes in fat cells from people who had lived through the brief period of Cold War nuclear bomb testing from 1955 to 1963. People whose fat cells were deposited before the onset of testing nevertheless incorporated radioactive matter after, showing that their fat cells were being replenished.The fact that fat cells are constantly dying and being replaced could potentially offer an opportunity to develop new anti-obesity therapies, the researchers suggest.


Author contact:
Kirsty Spalding (Karolinska Institute, Stockholm, Sweden)Tel: +46 70 437 1542; E-mail:


kirsty.spalding@cmb.ki.se