DIET IN A PILL

By Jeffrey Kluger

As if it weren't already hard enough to get Americans to eat less and exercise more, an advisory panel to the Food and Drug Administration last week gave the green light to yet another weight-loss shortcut, recommending approval of a new drug, called orlistat, that prevents the body from absorbing as much as 30% of the fat it takes in.

The new diet-in-a-pill, to be marketed as Xenical, works by disabling pancreatic enzymes that help the intestines absorb the fat in foods. The drug produces "a kind of intestinal aversion" to fat, explains Dr. Jules Hirsch of Rockefeller University, an FDA adviser. "Patients learn there are consequences to eating more."

Consequences, indeed. Fat that isn't absorbed has to go somewhere, and orlistat users find out in a hurry just where. Among the drug's less elegant side effects are loose stools and oily intestinal leakage. Moreover, about 20% of those who take orlistat absorb not only less fat but also fewer nutrients--particularly vitamins D and E and beta carotene.

Orlistat is not the only weight-loss nostrum to target the mass market lately. Last year the FDA approved Redux, a drug that controls appetite by boosting levels of the neurotransmitter serotonin, producing a sort of chemically induced illusion of being full. A similar medication, sibutramine, is expected to be approved soon. Both drugs have side effects, however, including fatigue and insomnia.

Doctors are quick to point out that the new diet pills are intended for only the truly obese. That caveat notwithstanding, however, such companies as Hoffmann-La Roche--orlistat's manufacturer--can be forgiven for feeling that they have hit the pharmaceutical jackpot. About 58 million Americans already spend $30 billion annually battling the scale. Even if the new drug doesn't slim waistlines, it will surely fatten someone's bottom line.

--By Jeffrey Kluger