Hormone Leptin Tweaks Hungry Brain
High-Calorie Foods May Be Especially Tempting When Leptin Is Lacking
Oct. 29, 2007 -- The fullness hormone leptin may make it easier to resist high-calorie foods.
That news comes from a new study of people with a rare genetic disorder that causes leptin deficiency and obesity.
Leptin-related brain areas may be good targets for obesity treatment, the researchers suggest.
They studied three leptin-deficient adult patients from a Turkish family.
The patients got brain scans using functional magnetic resonance imaging (fMRI) at the University of California, Los Angeles (UCLA).
During the brain scans, the patients saw photos of high-calorie foods (such as fried chicken, cheeseburgers, and pizza), low-calorie foods (such as strawberries and salad), or brick walls.
The patients rated their hunger while each picture was displayed.
They were hungriest when they saw the photos of high-calorie foods. Strawberries and salads didn't rate as highly on the hunger scale.
The brain scans backed that up, showing increased activity in hunger-related brain areas when the high-calorie foods were displayed.
After the initial brain scans, the patients began getting daily leptin shots for two years.
With leptin treatment, the patients lost weight and were less hungry when they saw images of high-calorie foods during follow-up brain scans.
The findings may provide clues about hunger, the brain, and leptin -- and those clues could yield new obesity treatments, note the researchers.
They included graduate student Kate Baicy and Edythe London, PhD, of UCLA's David Geffen School of Medicine.
Their study, published in Proceedings of the National Academy of Sciences, isn't the first of its kind.
In August, British researchers reported similar results when they showed pictures of food to two teens with leptin deficiency.