The new nonprescription diet drug Alli is flying off store shelves, but most people who use it will lose very little weight and may experience embarrassing side effects.
Pharmacies are reporting brisk sales of Alli (pronounced like the noun "ally"), which is sold by drugmaker GlaxoSmithKline and is the first over-the-counter diet drug to win FDA approval. Unlike other prescription weight-loss drugs such as Meridia and the generic phentermine, Alli doesn't make you feel full, reduce cravings or curb your appetite. Instead, it prevents the body from breaking down and absorbing fat.
The active ingredient in Alli is orlistat, which is found in a higher dose in the prescription diet drug Xenical. Alli blocks about 25 percent of the fat you eat; Xenical blocks one-third of the fat you ingest. For instance, a half-cup serving of Haagen-Dazs ice cream has about 320 calories and 19 grams of fat. Alli, which is taken with meals, would prevent the body from absorbing about 4.75 fat grams or about 43 calories. If you consume about 2,000 calories a day and eat about 30 percent fat, the fat-blocking benefits of Alli would translate to about 150 calories a day. A pound of weight loss equals 3,500 calories.
The downside of Alli is the fat it blocks can come out of your body in embarrassing ways. The Glaxo Web site, myalli.com, warns the drug can cause gas with oily discharge as well as frequent or loose stools. The site suggests it's probably a "smart idea" to wear dark pants and bring a change of clothes to work if you use Alli.
To avoid the side effects, Glaxo suggests limiting fat intake to 15 grams a meal. Many Americans consume 80 to 100 grams of fat a day. Glaxo officials concede that many people would lose weight on their own with a diet that's moderate in fat, but that the pill helps them lose more weight.
"If you'd lose 10 pounds on a diet, you'll lose 15 pounds by adding Alli to your diet," says Vidhu Bansal, director of medical affairs for Glaxo's consumer-health division.
If someone is consuming a diet already low in fat and high in carbohydrates, they likely won't get much benefit from Alli. However, doctors say most people are eating far more fat than they realize.
Orlistat has been used by an estimated 28 million people worldwide and studied in 30,000 subjects in about 100 trials. In a 1999 Journal of the American Medical Association report, 1,187 dieters, who weighed an average of 220 pounds, took either a placebo or 120 mg of orlistat (twice the dose of Alli). After one year, individuals in the orlistat group lost an average of 19.27 pounds, about 50 percent more than the 12.8-pound average weight loss in the placebo group.
But as with most diets, the dieters couldn't keep the weight off. During the second year of the study, the orlistat users were given either the 120 mg dose or switched to 60 mg, the same dose in Alli. After a year, the 120 mg users gained back seven pounds, the 60 mg users gained 9.4 pounds and the placebo group gained 11.3 pounds. So after two years on the drug, the dieters lost an average of between 10 and 12 pounds — or about 5 percent of their body weight. The placebo dieters lost 1.5 pounds.
Some dieters lost far more weight. About 50 percent of the people who use orlistat lose at least 5 percent of their body weight. One out of five people who take the drug lose at least 10 percent of their body weight, according to Glaxo. "Even small amounts of weight loss offer clear-cut health benefits," notes Louis Aronne, director of the Comprehensive Weight Loss Clinic at Cornell University Medical College, who has studied the drug and consulted with Glaxo. "It's not for the average person who wants to take it and doesn't want to change their diet. It's for someone who is committed to making a change in diet and lifestyle."
Weigh-in
Here's what users of orlistat, the ingredient in Alli, can expect from the weight-loss drug:
— One in five will lose 10 percent or more of body weight.
— Half will lose less than 5 percent of their body weight.
— Side effects include gas, oily discharge and loose stools.
—The Wall Street Journal