Beware of overeating. Seems it triggers a metabolic response in the brain, even when a person hasn't gained weight.

Researchers from the University of Wisconsin-Madison say this is so, and previous research revealed that eating too much caused an inflammatory response in the liver, muscles, and other metabolic tissues, changes that underscore the development of type 2 diabetes. What wasn't known, however, was if the same pathway was at work in the central nervous system.

Turns out it is. Presenting their findings in the October issue of the journal Cell, researchers assert that a high-sugar or high-fat diet also increases the activity of this pathway in the brain. What's more, this same pathway is active in the brains of mice (yes, mice. Human trials have not yet begun -- although researchers believe their findings will also apply to us) predisposed to obesity. Once awakened, the pathway induces insulin resistance and the dysfunction of other hormones involved with appetite and weight control.