Americans spend millions on weight loss pills each year, but should we?

When it comes to losing weight, research and experts tout changes to diet and exercise. And this is for good reason: They work. And for weight loss to really make an impact on your health, losing between 5 percent and 10 percent of your bodyweight is the magic number. But to accomplish this, behavior must be modified, and that’s where the going gets difficult.

Americans are reaching into their wallets and buying diet pills. According to a telephone survey in which the Centers for Disease Control and Prevention (CDC) questioned nearly 9,500 people, the use of weight-loss supplements seems common among U.S. adults:

  • An estimated 15.2 percent of adults (women 20.6 percent, men 9.7 percent) have used a weight-loss supplement.
  • Highest use was among women aged 18 to 34 years (16.7 percent)
  • One in 10 (10.2 percent) participants reported taking a supplement for a year or more.
  • Almost one third (30.2 percent) of survey participants had used weight-loss supplements in the past year, and of that group, 73.8 percent used a supplement containing a stimulant such as caffeine and/or bitter orange.
  • Many adults are long-term users, and most do not discuss this practice with their physician.

Although millions of dollars are spent each year on products touting slimming benefits, the evidence for their effectiveness is questionable and the concern about their safety is real (to learn more about how supplements are regulated, see our article on the Dietary Supplement Health and Education Act (DSHEA)) -- especially considering that there are about 10 ingredients per product.

When researchers from the University of South Carolina at Columbia audited the nutritional labels of weight-loss products sold at 73 retail outlets, they found 402 products containing 4,053 separate ingredients. They then analyzed data on the effectiveness, safety precautions and side effects of the 10 most common ingredients. Modest evidence of effectiveness for green tea (Camellia sinensis), chromium picolinate, and ma huang (Ephedra sinica, which is now banned by the FDA), was found, but there was virtually none for the remaining seven -- ginger root (Zingiber officinale), guarana (Paullinia cupana), hydroxycitric acid (Garcinia cambogia), white willow (Salix alba), Siberian ginseng (Eleutherococcus senticosus), cayenne (Capsicum annuum), and bitter orange/zhi shi (Citrus aurantium). The biggest concerns about safety were for ma hung (or Ephedra), bitter orange and guarana (a form of caffeine). Researchers wrote in the December 2006 issue of the Journal of the American Dietetic Association that even though these supplements are widely available, there wasn’t a lot of education about them.

This buyer’s guide is meant to help you make sense of the ingredients listed on labels and familiarize you with the effectiveness, safety precautions and side effects these substances. Using information from the Food and Drug Administration (FDA), National Center for Complementary and Alternative Medicine and research studies, we have put together a easy-to-read resource so you can make an informed decision about these products, with the help of qualified professionals.

Before you buy:

  • Read the ingredients. Most diet pills contain multiple ingredients. Research each ingredient and make sure you’re not taking multiples of the same ingredient. For instance, caffeine is present in both green tea and guarana.
  • Talk to your doctor. Many of the supplements used for weight loss have side effects, and they have the potential to interact with each other and any medications you may be taking. She can help you do the research, tell you which ingredients to avoid and maybe help you find more effective ways to lose weight.
  • Weigh the risks and the benefits. Diet pills offer us hope of a quick and easy way to lose weight, but before you spend your money, find out the risks. Losing 3 pounds just may not be worth damaging your liver.
  • Take the manufacturers claims with a grain of salt. Manufacturers have been known to make false claims about their products just to get you to buy them. Don’t go by what they say on their website, do your own research. The National Center for Complementary and Alternative Medicine (NCCAM) and Office of Dietary Supplements (ODS) [] are good places to start, as is the Natural Medicines Comprehensive Database (NMCD), though a subscription ($9.97/month) is required.
  • Remember that the FDA hasn’t tested the safety of these diet pills. Unlike medications, the Food and Drug Administration (FDA) does not require proof of any supplement’s safety before it is put on the market. Only after it is on the market does the FDA have a responsibility to investigate any claims of serious side effects.
  • Research the manufacturers. Not all supplements are equal. A supplement can vary in quality and concentration depending upon who makes it. By doing a little digging, you can find out if there has ever been any complaints about a manufacturer’s quality or consistency.
  • Beware of Internet purchases. Products sold on the Internet can contain substances that have been banned by the FDA, such as ephedra. Remember these substances were banned for a reason, and there can be serious safety concerns with their use.

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