A: Our current understanding of the life cycle of fat cells, or adipocytes, is that the initial number is somewhat determined in utero during development of the fetus. The genetics of the fetus, the mother’s genetics, your health and your diet likely play a role. After birth, the size of fat cells and any further number of cells is determined by lifestyle as well as genetics. As we gain weight and become obese, fat cell size and numbers increase. With weight loss, the size of fat cells decreases, but the number of fat cells remains the same. There is a regular cycle of cell death, but these cells are typically replaced with new ones.

ANSWERED BY:

Susan M. Kleiner, Ph.D., RD, FACN, CNS, FISSN, one of the foremost nutrition authorities on eating for strength, owner of High Performance Nutrition and author of Power Eating.