In an approach to childhood obesity long considered taboo, the nation's two prescription weight-loss drugs, Xenical and Meridia, are now being tested in children and teenagers.
This first large-scale effort to examine the usefulness of diet drugs in the young reflects a growing need, says Dr. Ken Fujioka, director of the Nutrition and Metabolic Research Center at the Scripps Clinic in La Jolla. Health experts say 10% to 15% of the nation's children are overweight and that the number is climbing.
"I don't think we ever dreamed of doing this 10 years ago, or even five years ago," says Fujioka, who is investigating Xenical's effectiveness among children ages 12 to 16. "But this is a scary problem because it's increasing [so rapidly]. So now we're looking at more aggressive measures."
Treating obese children with medication still elicits strong objections from many health professionals, however. They say a focus on medication ignores the fundamental problems--too much food, too much fat and too little exercise--that has precipitated the childhood obesity epidemic.
"I think a pharmacologic approach for childhood obesity is not the best approach," says Dr. Francine Kaufman, chief of endocrinology and metabolism at Childrens Hospital Los Angeles. "The best approach is a public health solution. We need to learn a lot more about child obesity and why this is occurring now."
But parents of obese children are increasingly desperate to help their children, experts say. Many overweight children have at least one overweight parent who fully understands how hard it is to lose weight.
Cathy Dangel kept thinking her daughter, Eryn, would shed weight naturally as she grew during adolescence. But last summer, Dangel, who lives in San Diego, decided it was time to act. Her daughter was about to enter high school and she was 40 pounds overweight.
"I thought she would outgrow it, but that never happened," Dangel says. "And I felt if I said something about the problem, that might be more detrimental to her self-esteem."
Dangel, who also struggles with a weight problem, heard about Fujioka's study at Scripps while attending a class there. Eryn agreed to enter the study, although Dangel had some reservations--mostly because the drug can trigger sudden diarrhea.
"I thought if she had an accident at school that would be even worse than being overweight," Dangel says. "But Eryn felt she could handle the side effects."
Eryn has lost 12 pounds since September and hasn't had problems with sudden diarrhea. The entire Dangel family has also changed their eating habits.
"We've learned to study food labels and cook food differently," Dangel says. "One of the nurses at Scripps even said that Eryn probably doesn't need Xenical any more because she is keeping her fat and calories down. So we don't know if [the medication] is helping or if it's the other things. But the medication really gave us the impetus to get going on the problem."
To be sure, Xenical, approved in 1999, and Meridia, approved in 1997, are a far cry from previous generations of diet drugs. Those were typically amphetamines that suppressed appetite and caused a range of serious side effects, such as insomnia, mood changes, cardiac arrhythmias and addiction. Both of the new studies are sponsored by the manufacturer.
Xenical, made by Roche Laboratories, works by reducing the absorption of about one-third of dietary fat. The drug also limits intake of some vitamins--a potentially serious side effect in children, who are still growing, says Fujioka. In particular, Xenical can block the absorption of fat-soluble vitamin D, which helps metabolize calcium.
Exposure to sunlight generates enough vitamin D in most people. But children taking Xenical in northern climates may not get enough of the vitamin during winter months without taking a vitamin supplement, Fujioka says.
Xenical can also cause excessive gas and increased bowel movements, both of which may be urgent and difficult to control--particularly after meals that contain more fat than is recommended.
"This is tough for kids," Fujioka says. "If they have diarrhea at school, that will be so difficult because they don't want to do anything else to draw attention to themselves. But that may also be why Xenical might work: It forces kids to police themselves, and they begin to learn what is fat."
The Xenical study, which involves about 450 kids and some 30 research centers, will explore the effects of vitamin loss as well as safety and effectiveness. Investigators will compare a group of kids who receive Xenical along with counseling on nutrition and exercise to a group that receives counseling only.
Studies show that about two-thirds of adults treated with Xenical and a diet plan lost at least 5% of their body weight after two years compared with 50% of the people treated with diet alone.
Meridia, made by Knoll Pharmaceutical Co., works by affecting chemicals in the brain involved in regulating appetite.