With obesity an epidemic practically worldwide, drug companies have been in a race to find a diet pill that can be sold without a prescription. Glaxo Smith Klein won that race with a new drug called Alli.  But, as VOA's Carol Pearson reports, it is no magic pill.  Alli requires a commitment to a change in eating habits.

Americans alone spend more than a $1 billion a year on weight loss products. Imagine if the tens of millions of people worldwide had easy access to a diet pill.

"The market is so enormous and there are so many overweight people desperate for solutions," says Professor Kelly Brownell is director of Yale University's Center for Eating and Weight Disorders.

Alli is a non-prescription version of Xenical, a more potent, prescription-only weight loss drug. Both drugs are brand names for orlistat. They work by blocking fat in the digestive track.  The manufacturer admits Alli is not a magic pill, and users need to make a commitment to lifestyle change.

"The typical pattern for people on weight loss drugs is to go into it with a lot of enthusiasm," says Professor Brownell. "Many people don't lose as much as they like. They get discouraged and go off the drug."

Glaxo Smith Klein advises people to use Alli in combination with a low-fat diet and exercise.  But there are some side effects.  The pill can cause gas, painful stomach cramps and diarrhea.

While the U.S. Food and Drug Administration approved Alli, the FDA's health advisory panel rejected another weight-loss drug - rimonabant - because studies show it increases the risk of suicidal thoughts in some patients.  Rimonabant's manufacturer suggested that physicians screen patients before they prescribe this drug. Rimonabant is available in Europe under the brand name Acomplia.

Experts say while weight-loss drugs can be helpful, they miss the larger point, which is more emphasis on preventing obesity in the first place.