Teen Obesity: Does Fat-Fighting Pill Help?

June 14, 2005 -- A new study shows that obese teens who dieted, exercised, and took the fat-blocking pill Xenical lost more weight in a year than those who worked out, cut calories, and took a placebo pill.

However, that does not make Xenical a "magic bullet" against teen obesity. The teens were asked to make real changes in their habits besides popping pills. The pill's impact after a year isn't known; neither is its impact on overweight (but not obese) teens.

Gastrointestinal side effects were more common with Xenical, but no serious problems arose, say Jean-Pierre Chanione, MD, PhD, and colleagues. Their year-long study, published in The Journal of the American Medical Association, was funded by Xenical's maker, Hoffmann-La Roche.

Weighty Problem

Chanione's study starts by laying out the cold, hard numbers on teen obesity. The researchers say obesity is increasing among adolescents worldwide, growing by 15% to 23% in some ethnic minorities in the U.S.

Extra pounds aren't only burdening U.S. teens. The prevalence of overweight adolescents has grown by 8% to 21% in Northern Europe and 17% to 23% in Southern Europe, writes Chanione.

Chanione works at the endocrinology and diabetes unit of British Columbia Children's Hospital in Vancouver. He reports having received honoraria from Hoffmann-La Roche for speaker's presentations, says the journal.

Beating the Odds

Losing extra weight is tough for many people, but adolescents are a "notoriously difficult to treat population," write the researchers. They point out that the "vast majority (83%)" of obese 10- to-15-year-olds become obese adults.

Of course, that fate is not written in stone. People can change course at any time. So while it's never too late to make positive changes, the sooner that happens, the better.

Obesity has long been linked to a host of health problems, including greater risk of heart disease, stroke, and cancer.

Xenical Drops Pounds

Chanione's study included 593 obese youths aged 12-16. They were seen at 32 U.S. and Canadian research centers. All of the teens had a body mass index (BMI) -- an indicator of body fat -- at or above the 95th percentile for their age.

Participants either took 120 milligrams of Xenical or a placebo three times per day for a year. The pills were identical, except the placebo lacked Xenical's active ingredient. The participants did not know which pill they were taking.

Xenical doesn't affect appetite. Instead, it helps promote weight loss by blocking about 30% of fat from getting absorbed into the bloodstream.

Guidelines for diet and exercise were issued, but the study doesn't say how many teens stuck to those plans.

About a Third Dropped Out

About one-third of teens in each group dropped out during the study.

Reasons for dropping out were similar in both groups, say the researchers. The dropout rate of 35% to 36% is "well within what is usually seen in obesity trials, particularly those of more than one-year duration," write the researchers.