Dr Oz scolded over his quack dieting products

A US senate panel investigating bogus diet product ads took celebrity doctor Mehmet Oz to task this week for touting weight-loss products on his TV show.

Missouri Democratic Senator Claire McCaskill, the chairman of the commerce subcommittee on consumer protection, said Oz had a role in perpetuating weight-loss fraud through his show.

"I don't get why you need to say this stuff because you know it's not true," she said at the hearing.

McCaskill said Oz's promotion tended to boost sales and prompted scam artists to sell questionable products using deceptive ads.

"When you call a product a miracle, and it's something you can buy and it's something that gives people false hope, I just don't understand why you need to go there," McCaskill said.

Oz, the host of The Dr Oz Show, said the products gave people hope to keep trying to lose weight. Nearly 70% of Americans are overweight or obese. He said the No1 topic asked about on his website was weight loss.

"I actually do personally believe in the items that I talk about on the show," Oz, a Columbia University professor, said.

"I recognise that oftentimes they don't have the scientific muster to present as fact. I would give my audience the advice I give my family all the time, and I have given my family these products."

Part of the hearing focused on green coffee extract, a dietary supplement Oz touted in 2012 as a "miracle". The show heightened interest in the product, and Oz testified that he devoted much of a second show to telling viewers how his name was being used unscrupulously to sell it.

Federal Trade Commission official Mary Koelbel Engle testified that the agency filed suit over the supplement, charging deceptive claims and promotion.

Weight-loss products topped a 2011 FTC survey into consumer fraud, she said.

Americans spent around $2.4-billion (more than R25-billion) on weight-loss services last year. The figure is expected to rise to $2.7-billion by 2018.