The number of people with one or more of the adverse complications of obesity, including type 2 diabetes and heart disease is rapidly increasing.

Drugs designed to treat obesity have shown limited efficacy and have been associated with serious side effects, largely because we have limited understanding of the effects of obesity on our natural mechanisms of body weight control.

For example, while great strides have been made in our understanding of how the brain controls our desire to feed, as well as the processes underlying the balancing of energy intake and expenditure, little is known about how the are altered by obesity. Two independent groups of researchers have now generated data that begin to address this issue.

A team of researchers led by Michael Schwartz, at the University of Washington, Seattle, has found that in both humans and rodents, obesity is associated with neuronal injury in an area of the brain crucial for body weight control (the hypothalamus).

A second team of researchers, led by Jeffrey Flier, at Beth Israel Deaconess Medical Center, Boston, has determined that turnover of nerve cells in the hypothalamus is inhibited by obesity. 

Published in the Journal of Clinical Investigation