Sunday, November 1, 2009

Are diet pills the answer to weight loss

Question: I haven't been successful at losing weight. I see ads for weight-loss supplements and drugs. Do they work? Are they safe?

Answer: Advertisements for weight-loss supplements seem to be everywhere. "Eat the foods you love and still lose weight" and "Exercise in a bottle" are among the marketing ploys that sound too good to be true. For the most part, they are.

Take a look at the fine print on these products and you'll see that none of their claims have been verified by the Food and Drug Administration, which is responsible for testing the effectiveness of food and drugs. For example, a cold medicine that claims to relieve nasal congestion must be proven to do so.

But weight-loss aids fall into a gray area because they are neither foods nor drugs. Rather, they are classified as dietary supplements, a category created in 1994 in response to pressure to loosen the FDA's tight control over some products.

As a result, nutrients, herbs and plants that supposedly have medicinal value can be sold without being tested for effectiveness or safety as long as they do not make direct health or therapeutic claims. So although manufacturers cannot say that their weight-loss aids will cure obesity, they can make indirect and unproven claims in advertisements and on labels.

The FDA can, however, take a product off the market if it is found to be unsafe. For example, the FDA banned the sale of ephedra in 2004 after the compound was linked to several deaths.

But despite the ban on ephedra itself, supplements containing ephedra-like compounds (including ephedrine, norephedrine and methylephedrine) are widely available over the Internet and in stores.

In supplements they are often found in combination with caffeine or plant sources of caffeine, such as guarana and yerba mate. Two other ingredients found in some supplements -- bitter orange and country mallow -- contain chemicals related to ephedra and should also be avoided.

You should also steer clear of chitosan and guar gum, two more compounds found in weight-loss supplements, because studies show they don't help people lose weight. The FDA has also deemed spirulina (blue-green algae) ineffective.

What about the other substances found in weight-loss supplements

The evidence as to whether they work is unclear, because study results are either insufficient or conflicting. And although some seem safe, others have unknown safety profiles. As a result, the authors of a study published in the American Family Physician say that people should be cautious about using any of them.

If you decide to use a supplement, let your doctor know, and be sure to report any side effects immediately.

Weight-loss drugs are a different story. The first over-the-counter, FDA-approved weight loss drug hit stores in 2007. Called Alli, it is identical to the prescription drug orlistat (Xenical), except in a lower dosage. It blocks the absorption of fat in the intestines and must be taken before every fat-containing meal.

Other prescription weight-loss drugs include those that suppress or regulate appetite by altering levels of brain chemicals: sibutramine (Meridia) and phentermine (Adipex, Ionamin and others). But these drugs don't always work and little is known about the safety of longer-term use.

Your best bet: Talk with your doctor about your desire to lose weight, and work together to come up with a strategy that's safe, effective and something you can stick to.