At least six million obese teenagers in the United States are candidates for weight-loss surgery, experts estimate. Fewer than 1,000 of them get it each year.
Many of these adolescents already have complications of obesity, like diabetes or high blood pressure. But doctors have been uncertain just how well surgery works for young patients, and whether they can handle the consequences, including a severely restricted diet.
A new study provides some hopeful answers. Researchers followed 161 teenagers aged 13 to 19, and 396 adults aged 25 to 50, for five years after weight-loss surgery.
The teenagers actually fared better than the adults. The adolescents lost at least as much weight, and were more likely to see high blood pressure and diabetes ease or go away , the investigators reported on Wednesday in the New England Journal of Medicine.
“This really changes the game,” said Dr. Amir Ghaferi, a bariatric surgeon at the University of Michigan, who was not involved in the research.
The paper, he said, added to evidence that obesity, like cancer, is best treated early, before long-term damage from related conditions, such as high blood pressure and diabetes, sets in.
[Read more about teenagers and bariatric surgery.]
To have the surgery, teenagers in the study had to meet the same criteria as adults: a body mass index of at least 35 — for instance, a person who is 5 feet 2 inches tall and weighs 192 pounds or more — and obesity-related health problems.
Alternately, the adolescents could have a B.M.I. of at least 40 — such as a person who is 5 feet 2 inches tall and weighs at least 220 pounds — without other conditions linked to obesity.
There is no exact data on the number of teenagers who meet those criteria in the United States, said Dr. Thomas Inge, chief of pediatric surgery at Children’s Hospital Colorado and lead author of the new study.
He estimated that about 8 percent of American teenagers would qualify.
“These are not kids who are pleasantly plump,” said Dr. John Morton , a bariatric surgeon at Yale University. “Once you have a B.M.I. of 30, it is really difficult to lose weight on your own.”
There is no other treatment that results in a substantial and sustained weight loss in people who are severely obese. But the operation, gastric bypass surgery, is demanding. Surgeons close off most of the stomach, leaving a small pouch, and reroute the intestines. Afterward, patients must eat tiny meals at frequent intervals for the rest of their lives.
It is a scenario that gives many parents pause. Should their teenagers wait, hoping science will come up with a less drastic solution? Or should their children have the operation before even more serious harm to the body occurs?
Adding to the quandary is the fact there are just six accredited bariatric surgery centers in pediatric hospitals. Although some adult programs operate on teenagers, most of such procedures are done in pediatric settings, Dr. Morton said.
Adults, by contrast, may choose from 850 accredited medical centers for weight-loss surgery.
Although the new study included adolescents with B.M.I.s of 35, most were much heavier. The average was 50, the same as the average for adults in the study.
For most of the adolescents, the surgery was a success. On average, they lost about a quarter of their body weight, enough to make life much easier and for most to shed health problems.
The teenagers weighed 324 pounds on average when they had the surgery. Five years later, the figure was 244 pounds. The adults weighed the same at the start and had a nearly identical result .
An unlucky minority of patients — both adults and teenagers — did not fare as well. Some remained saddled with high blood pressure or diabetes. A few lost almost no weight, or even gained weight, in the five years after the surgery.
The study did not randomly assign patients to have the surgery or not, which is the gold standard for clinical research. Since the adults had been obese for a much longer time, their condition might have been harder to treat with surgery. That makes it difficult to directly compare the teenagers and adults.
But Dr. Ghaferi said the message is clear: It is best to intervene early. And if that is true, other experts wondered, what about even younger children?
“What if an eight-year-old comes in, or a ten-year-old comes in, and they are severely obese? Why don’t we offer this treatment and study the results?” Dr. Inge said.
Already he has operated on children who are severely obese and have related medical conditions. The question now, he said, is whether to operate even before a child develops high blood pressure, diabetes, or sleep apnea.
That question will require careful study, with researchers following children for years after surgery, Dr. Inge said.
Even operating on teenagers raises issues that may not apply to adults. Can a miserable adolescent, for example, really can give informed consent to such a drastic, life-changing operation?
And can a teenager be expected to commit to following the very restricted diet required after the surgery, not to mention taking the needed vitamins and minerals?
“Are they prepared to do that for the rest of their lives?” asked David B. Sarwer, a psychologist at Temple University who works with bariatric surgery patients.
Substantial weight loss can have unexpected psychological consequences in teenagers, he added.
Severe obesity “sets adolescents up for stigmatization,” he said. A severely obese teenager “is likely known by every other student in the high school not because she is a prom queen, but because she is physically the largest student in the school.”
Stigma often leaves teenagers isolated and lacking social skills, a deficit that can hinder their development even after surgery to lose weight. And when formerly obese teenagers go to college, Dr. Sarwer said, often they are so ashamed of having been fat that they keep it a secret.
Yet weight-loss surgery can be transformative.
Eric Decker, 33, a bartender and freelance makeup artist in Detroit, had the operation in 2006 when he was 17. He was 5 feet 10 inches tall and weighed 385 pounds; no amount of dieting seemed to help.
He tried to find a surgeon in South Carolina, where he lived, to operate on him, but no one would do it. He was referred to Dr. Inge, then at Cincinnati Children’s Hospital.
Mr. Decker lost more weight than most — he now weighs between 205 and 210 pounds.
He speaks up now when someone speaks derisively of a person who is obese. He knows how it feels to be shunned for what medical researchers now deem a chronic disease, not a lifestyle choice.
Without that experience, he said, “I don’t think I would have that lens of compassion for people with their struggles.”