Leaner pork for consumers could be a benefit of research on human obesity, according to scientists with the USDA’s Agricultural Research Service.

Scientists have been intrigued by two hormones, neuropeptide-Y and leptin. These hormones work both in pigs and people like a traffic light. Neuropeptide-Y, found in the brain, is the “green light” that stimulates appetite. Leptin, the red light, is in fat; it signals the brain that the body is nourished.

ARS researchers in Athens, Ga., have found that giving pigs leptin injections increased the amount of growth hormone in their bodies and made them eat less.

Theoretically, this means the potential exists for meatier, leaner pork because growth hormone produces muscle. After the extra growth hormone has built muscle, the pig’s body would break down the hormone naturally so the meat would contain no residue.

The scientists caution that much more needs to be learned about leptin. A group of researchers in ARS and the University of Georgia are trying to understand how animals process this hormone. ARS scientists in Beltsville, Md., for example, are working on treatments to counter leptin’s appetite-suppressing effects. ARS colleagues Columbia, Mo. are looking at how growing piglets use leptin.

Scientific contact: C. Richard Barb, USDA-ARS, Richard B. Russell Research Center, Animal Physiology Research Unit, Athens, Ga. Phone: (706) 546-3584, fax 546-3586