Scientists have long known that fat cells in their early stages proliferate, but researchers with the Johns Hopkins School of Medicine say they've discovered that such cells specifically need to copy themselves at least twice before they can mature into full-fledged fat-storing cells that no longer divide.
Studies on mice showed the genes required for storing fat were only turned on after at least two cycles of fat cell division, and when the division was disrupted, the fat cells did not mature.
The process appears to be nature's system of ensuring that the body can always store fat and survive when food is unavailable. However, it may also explain why obesity levels are high in many cultures where food is not scarce, as excess calories are stored even when they are not needed.
Significantly, the cell division process that lets the young fat cells mature appears to be different from other cell types. The researchers speculate that one approach to preventing the body from storing excess fat would be to somehow block the fat cells from maturing, but the overall impact on the body's health would need to be considered.
The findings appear in this week's online edition of the Proceedings of the National Academy of Sciences.
Here's more information on weight loss and control from the National Institute of Diabetes and Digestive and Kidney Diseases.