Imagine being able to lose weight from all your trouble spots: Belly, hips, thighs and arms, all without feeling hungry.

Sound too good to be true?

Some doctors say it is, but a growing portion of medical professionals disagree and are offering the diet at their practice.

Tammy Settles was 180 pounds heavier just one year ago when she turned to is the HCG Diet.

HCG is a pregnancy hormone that, among other things, burns the mom's belly fat to feed the baby if the mother isn't getting enough nutrients.

Now women who aren't pregnant, and men as well, are using that hormone, giving themselves daily injections while only eating 500 calories a day.

"Making them put on a 500 calorie diet, to make it look like they're starving, so that the body thinks it has to feed the baby," explains Dr. Peter Fontinos.

Dr. Fontinos is the medical director of Revita Medical Center in Charlotte, North Carolina.

He's treated hundreds of patients, who believe it or not, say they are not hungry while on the HCG diet.

"In actuality you're not eating just 500 calories, you're eating 500 calories plus your own body fat which is equivalent to 1500, 4000 calories," he says.

Other doctors say there's no clinical evidence the diet works.

"It's very clear from more than a dozen studies that the hormone does nothing, but it's really 500 calorie a day diet that causes dramatic short term weight loss," says Dr. Louis Aronne, Director of the Comprehensive Weight Control Program at NY-Presbyterian/Weill Cornell.

This use of the hormone is not FDA approved.

Representatives for the agency say, "HCG has not been demonstrated to be an effective adjunctive therapy in the treatment of obesity."

Still, supporters say patients provide all the proof.

"The success rate is 99.9% here at the clinic, the success rate with other fad diets is nominal," says Revita Aging CEO Don Nicholas.

The diet costs roughly $1,000 per session.

Patients following the diet are on the injections and restricted diet for at least 26 days, but no more than 40.

There are risks involved including an increased risk for blood clots, depression, and a life-threatening condition called ovarian hyperstimulation.