Danger Diets: Doctors Warn Against 'Miracle' Weight Loss

Rush Limbaugh's recent weight loss sent shivers down Janet Chrostowski's spine.

It wasn't that the radio talk-show host dropped almost 90 pounds in less than five months that worried Chrostowski, a Hamot Medical Center registered dietitian.

It's how Limbaugh lost the weight.

Limbaugh said on his show that he hooked up with a Florida-based weight-loss center that combines a low-calorie diet with office visits and pills, including appetite suppressants.

"Over-the-counter appetite suppressants are not proven to be effective or safe," Chrostowski said. "They don't work."

Diet pills have been around for decades, promising a quick and painless way to lose weight.

The problem, Chrostowski said, is that most of them, especially the ones you can buy without a prescription, are a waste of your money.

"The makers of these pills say in their ads that they can decrease your appetite, control your hunger and boost your metabolism," Chrostowski said. "It's simply not true."

Even worse, some appetite suppressants are dangerous.

Herbal dietary supplements often used to contain ephedrine. It did lightly suppress people's appetites, but it also made their hearts beat faster and increase their risk of heart attack, stroke and death.

In 2004, the Food and Drug Administration banned the sale of ephedrine in any dietary supplement sold in the United States.

Another herb sometimes used to control hunger, St. John's wort, doesn't interact well with prescription medication such as blood thinners, antidepressants, heart medications or birth control pills.

It can cause the body to absorb those medications more slowly or quickly than usual.