Few children who become obese are able to lose and keep off weight with diet and exercise alone, leading some doctors to prescribe drugs, such as the diabetes drug metformin, to treat childhood obesity. However, a new study suggests that metformin may not help kids and teens without diabetes lose weight over the long term.
The study, which reviewed information from previous research, found no evidence that children and teens who took the drug lost more weight after one year than those who did not take the drug.
While some adolescents who took the drug did experience short-term weight loss (six months or less), the effect was modest, and it's not clear whether such limited weight loss would actually improve their health, the researchers said. [Lose Weight Smartly: 7 Little-Known Tricks That Shave Pounds]
Given the current evidence, metformin has not been shown to be superior to other weight-loss treatments for kids, such as diet and exercise, the researchers said.
"Unfortunately, this drug is not going to be the answer," said study researcher Marian McDonagh, of Oregon Health & Science University. Overall, the drug does not appear to provide enough weight reduction for children to experience meaningful health benefits in the long term, McDonagh said.
Still, it's possible that certain groups of children, such as those who are very obese, may benefit from taking the drug. A large study is needed to identify these groups, the researchers said.
The study analyzed information from 14 previous studies (eight in the United States and others in Canada, Australia, Mexico, Europe, Iran and Turkey), which included a total of 946 children ages 10 to 16 who did not have diabetes. The children's body mass indices (BMIs) ranged from 26 to 41. In most studies, children who took metformin also engaged in lifestyle changes aimed at helping them lose weight.
On average, children who took metformin for six months achieved a 3.6 percent greater reduction in their BMI compared with those who practiced lifestyle changes alone.
However, studies in adults suggest that, in order for a weight-loss treatment to lead to meaningful improvements in health down the road, it needs to reduce BMI by 5 to 10 percent, McDonagh said.
Children in the studies who took metformin for a year saw about the same decrease in BMI as those who practiced lifestyle changes alone. And after one year, both groups started to slip back to their original weight.
The researchers would like to see more studies on weight-loss treatments that involve a child's entire family. It's possible that family-based interventions may help children lose more weight — whether they are taking a drug or not — than interventions that don't consider the child's family, McDonagh said.
Metformin is approved by the Food and Drug Administration to treat children and adults with Type 2 diabetes.
The new study was published today (Dec. 16) in the journal JAMA Pediatrics.