He's quickly become one of America's most revered advice gurus and millions have bought his book on how to successfully lose weight.

Dr. Phil McGraw says his book"The Ultimate Weight Solution" is more than just a diet, it's a way to change your thinking and behavior.

But dietitians aren't so convinced about his methods. Diane Sprowl is a dietitian at the Barren River District Health Department and says some of his information is out-of-date. She's also wary of the many pills, shakes and bars that Dr. Phil encourages people to buy for his diet. In total, these can add up to $100 per month or more.

"A lot of the supplements he promotes, there's no scientific evidence that they do what he says they do," says Sprowl.

She says many of these pills are simply generic vitamins that can be bought for much cheaper at your local grocer. Nevertheless, Sprowl is glad Dr. Phil promotes changes in overall lifestyle, rather than simply dieting, as the real keys to successful weight loss.

For more information on what experts think about Dr. Phil's and other diets, you can visit the Center for Science in the Public Interest at www.cspinet.org and then click on the current issue of their newsletter.