By Mitchell Clute

In late April, pharmaceutical giant GlaxoSmithKline filed a citizen's petition with the U.S. Food and Drug Administration asking the agency to treat weight loss claims for dietary supplements as disease claims. The petition, filed jointly with the American Dietetic Association and other groups, argues that most Americans believe that weight loss supplements require side-effects warnings and are tested for efficacy.

The petition was denounced by supplements industry groups. Steven Mister, president of the Council for Responsible Nutrition, issued a statement saying, "We believe weight loss claims are legitimate and appropriate claim for products in the dietary supplements industry, provided these products have substantiation to support the truthfulness of these claims."

Currently, dietary supplements are allowed to make structure/function claims regarding weight loss, but not to claim that a supplement can eliminate a disease state, such as obesity. A claim that a product can help get you back in shape for summer, for example, is acceptable, while a claim stating that a product can help you lose 80 pounds in a few months is not. "Glaxo is arguing that consumers believe that any kind of weight loss claim for a dietary supplement is an obesity claim, so dietary supplements makers are really marketing drugs, and their products shouldn't be allowed on the market," said Mark Ullman of the law firm Ullman, Shapiro and Ullman, a NY-based law firm specializing in dietary supplements regulation. "It's preposterous."

Many in the supplements industry see the petition as an attempt to quash competition for GlaxoSmithKline's over-the-counter diet pill Alli, a low-dose version of Xenical approved for sale last June.

"Their motivation is purely economic," said Ullman. "Their OTC product is required to carry claims very similar to those used by responsibly marketed dietary supplements, and Glaxo is seeking to eliminate competition to Alli from store shelves. The only problem Glaxo has with their product is that it causes anal leakage, so consumers might tend to stay away from it."

Indeed, though Alli has had $141 million in sales since its launch, representing more than a third of the total nonprescription weight control market, the Mayoclinic.com Web site lists side effects including "hard-to-control bowel movements" and "gas and oily anal discharge".

Even before Alli was approved, GlaxoSmithKline began its campaign against weight loss supplements through a Web site named questioneverything.com, using the slogan "question everything you know about weight loss." The site directly criticized weight loss supplements, saying that claims that supplements can raise the metabolism are untrue and that such products simply stimulate the heart without producing "substantial weight loss."