The UltraShape procedure -- approved in Canada last year and approved in 50 other countries including Japan and much of Europe since 2005 -- "breaks down the fat cell and gets rid of the unwanted fat much like liposuction does, except it does it non-invasively, meaning there's no cutting, there's no anesthesia, there's no downtime, there's no recovery," Dr. Ari Benchetrit, a Montreal plastic surgeon, tells ABC-TV's "Good Morning, America."

UltraShape reduces fat thickness, typically in three sessions, and it doesn't harm surrounding skin, blood vessels, nerves or other tissue, studies indicate.

Clinical trials suggest an average loss of two to three inches after the three treatments, Benchetrit said.

The treatment is currently in Phase III U.S. clinical trials could be approved in a few years, doctors say.

Patients spend a half-hour under an UltraShape machine, and sound waves make fat cells under the skin vibrate at a very high speed, causing them to be destroyed, ABC's report said.

The fat is then carried to the liver, where it is removed from the body safely, advocates say.

But the procedure is not for someone who has a lot of fat to lose, doctors warn. In those cases, the procedure could release too much fat into the body, leading to serious health problems, such as heart disease and diabetes, they say.

The procedure would probably cost between $400 and $1,000, ABC said.