Special Report: The Hunger Hormone

INDIANAPOLIS (WISH) - Americans may soon have a new weapon in their war on weight. Scientists have discovered something called a hunger hormone that's partially responsible for making people feel hungry. Researchers in Indianapolis say knowing what causes those hunger pangs is the first step toward a pill that will turn off the urges.

Shelly Vail has fought her weight most of her life. Old pictures of her tell the story. She was a pretty girl who was stuck in a fat body.

"I didn't know myself. I was just living my life every day without really knowing who I was or what my purpose was," said Vail.

Shelly's story is one many people know all too well. Nearly 59 million people in the U.S. are considered obese. And the weight puts all of them, including Shelly, at risk for health issues. Shelly's kept her weight off for eight years the old fashioned way: consistent diet and exercise. But help may be on the way from the labs of Indianapolis-based Eli Lilly and Company.

Dr. Mark Heiman of Eli Lilly, found that a newly-discovered hormone, called ghrelin, made lab mice hungry.

"When we treated an animal with the growth hormone secretigog, they ran to the food and ate. And that was such a surprise, we've never seen anything do that," said Dr. Heiman.

Furthermore, an associate of Dr. Heiman's discovered the on/off switch for ghrelin. It's an enzyme called GOAT.

"Our hypothesis is for some subset of patients that we need to identify...can we now find a therapeutic compound that is safe and effective so we can go in there and turn the switch off," said Jesus Gutierrez.

Ghrelin is made from cells inside the stomach. That enzyme, called GOAT, activates it. Once it's made and activated, it travels to the hypothalamus region of the brain and triggers a feeling of hunger. Lilly researchers are focusing their efforts on controlling the enzyme. In fact, they are developing a pill that will block GOAT, thereby reducing hunger and spurring weight loss.

"What Lilly discovered recently is the specific enzyme in stomach cells that activates ghrelin, and this becomes a very exciting target for treating obesity," said David Bredt, MD, Ph.D. of Eli Lilly.

But before you throw out the calorie counter, there's something you need to know. There may be serious side effects to controlling the hunger hormone.

This past summer, in the journal "Nature Neuroscience", Dr. Michael Lutter of the University of Texas-Southwestern wrote, "Our findings support the idea that these hunger hormones don't do just one thing. Rather, they coordinate an entire behavioral response to stress and probably affect mood, stress and energy levels."

In the same article, Dr. Jeffrey Zigman issues a warning: "This new research suggests that if you block ghrelin signaling, you might actually increase anxiety and depression, which would be bad."

In other words, if you cut the hunger hormone to lose weight, you might also be at risk for a mood disorder. 24-Hour News 8 asked several people if that kind of risk would stop people from taking the weight loss pill.

"For me, I've had a lot of problems with anxiety and depression. So I wouldn't," said Natalie Zellers of Fort Wayne.

"I think a lot of people would go for it if there's a quick remedy, a solution, for a lot of people to try to lose the beginning weight," said Natalie's husband, Brett Zellers.

"Depending on how bad it got, I guess it wouldn't be so bad. But if it got to drastic suicidal levels, it's probably not a good idea," said Christen Feguson.

Shelly Vail admits she once took a weight loss pill and it worked temporarily. She lost 60 pounds and then regained it. Now, after having lost her weight the old fashioned way, she doesn't think pills are the answer.

"I guess I really still think that the only true way to be successful at losing weight is diet and exercise," said Vail.

Lilly researchers said they are very hopeful that the obesity pill will make it through clinical trials. That's a first step before it's available to the public. And, they say, people with type II diabetes might be helped the most, since many are struggling with weight.