Defective signaling through the melanocortin-4 receptor (MC4R) is the most common cause of severe childhood obesity. But while this form of obesity results largely from hyperphagia (abnormally increased appetite for and consumption of food), it is not necessarily high-fat or sugary foods that stimulate the behavior.
That’s what Brandon Panaro and Roger Cone, Ph.D., professor and chair of Molecular Physiology and Biophysics, found in a study published online April 8 by the Proceedings of the National Academy of Sciences. Mice in which both copies of MC4R were deleted actually had decreased preference for high-fat and high-sucrose foods compared with wild-type mice. Instead, these animals ate more of the low-fat standard chow.
“They consistently exhibited the most dramatic increases in caloric intake when given dietary variety,” Panaro and Cone reported. “The hyperphagia appears driven by variety and/or novelty, rather than by a preference for high-fat or high-carbohydrate foodstuffs.”
Understanding the reward value of different foods could help in designing specific dietary recommendations for children with melanocortin obesity syndrome, the researchers concluded.
This research was supported by a grant from the National Institutes of Health (DK070332).
