causes of obesity

Researchers have identified stem cells with the capacity to build fat. Although they have yet to show that the cells can renew themselves, transplants of the progenitor cells isolated from the fat tissue of normal mice can restore normal fat tissue in animals that are otherwise lacking it.

The findings may yield insight into the causes of obesity, a condition characterized by an increase in both the size and number of fat cells.

The brain can sense the calories in food, independent of the taste mechanism, researchers have found in studies with mice.

Their finding that the brain's reward system is switched on by this "sixth sense" machinery could have implications for understanding the causes of obesity.

For example, the findings suggest why high-fructose corn syrup, widely used as a sweetener in foods, might contribute to obesity.