Campus News

Professor’s research into hunger, appetite is more than a mouthful

Eating is a pleasure. But for too many of us, the signals that should tell us to stop with one piece of pie or one soda don’t work. These signals are what foods and nutrition researcher Silvia Giraudo is exploring.

“There are at least two systems involved in food intake: hunger and appetite,” said the associate professor in the College of Family and Consumer Sciences. “If you’re only eating for hunger, you’ll eat anything. But appetite refers to the pleasure you receive from eating something that you like.”

Hunger and appetite involve a variety of chemical reactions in our bodies. Signals travel from our brain to the stomach and back to our brain to let us know whether we’re really, really hungry or whether we have an appetite for something special, like an ice cream sundae. But sometimes those signals get blocked.

“Scientists have identified a peptide that blocks the receptor for satiety,” Giraudo said. “If we give one dose of this peptide to our animal models, they will overeat for six days.  My belief is that this peptide either alters the receptor or it recruits another system, such as the opioid system, to ensure that we continue to eat for pleasure.”

The opioid system is the brain circuitry that also is involved in addictive behavior, such as addictions to caffeine, nicotine and alcohol. Giraudo maintains that for those who become morbidly obese, food also may be an addiction.

“Addiction is a hard word,” she said, “but I think it is the correct word. We all can have some addiction for particular foods. But in some cases, it appears that addiction to one or two ‘treats’ can become an addiction we can’t control.”

Although Giraudo spends many hours in her lab searching for the chemical links to obesity, she also considers nutrition education vital. For the past two years, Giraudo, a native of Argentina, has taken on the added task of increasing her students’ knowledge of the Hispanic and Latino cultures by leading three-week programs for them in Xalapa, Mexico.

“We have had a huge immigration of Hispanics in the U.S., and I know our students will be dealing with these immigrants either at hospitals, in clinics or even in private practice,” she said. “I wanted them to have some understanding of the culture and language, but I also wanted them to see the different approach of health officials in other countries.”

The students live with host families during their stay and take daily trips to a state-run hospital, similar to Grady Hospital in Atlanta.

“Unlike in the United States, the dietitians at the Xalapa hospital go on rounds with the doctors,” Giraudo said. “The doctors talk specifically with the dietitians concerning the patients’ diets. Also, the dietitians deliver the food to the patients and at the end of the meal, the dietitian takes note of what was consumed.”

During their stay, the students visit every floor of the hospital—the burn unit, internal medicine, pediatrics and maternity. In fact, the head of the obstetrics-gynecology unit allows the students to go into the delivery room to see a baby born. “That’s never an option for dietitians in the U.S.” Giraudo said.