The study, by Binh Nguyen at the University of Sydney and colleagues, included 151 teenagers in a 24-month program called Loozit, based on group behavior-modification sessions for teens and their parents.
At the 12-month mark, 40 percent of the teens had reduced their body mass by at least five percent and a quarter had reduced by at least 10 percent, though most remained overweight.
Despite the small effect on weight, Elissa Jelalian of Brown University in Providence, Rhode Island, said the results are promising because the program was less intensive than other weight loss efforts, and yet had nearly the same impact.
"I think it's certainly worthy of further investigation," Jelalian, who was not involved in the new work, told Reuters Health.
During the first two months of Loozit, the kids, who were between 13 and 16 years old, participated in seven weekly group sessions that focused on healthy eating habits, increasing physical activity, decreasing time spent in front of a screen and improving self esteem.
They also spent some time exercising and preparing and tasting foods during the sessions.Parents, too, attended weekly group sessions where lifestyle-modification was discussed.
For the next 22 months, teens and parents went to booster sessions every three months.
The study's results, published in the Archives of Pediatrics & Adolescent, only include outcomes from the first 12 months of the program, which 124 kids completed.
Jelalian said other weight loss programs for kids have relied on group interventions, "which I think can be helpful. They try to mobilize other kids their age who are dealing with similar challenges and to create a peer group."
The differences between Loozit and other programs is that the kids only go through 14 sessions over two years, compared to about 20 in other cases, and the discussions are held in community locations rather than in academic or hospital settings.
Most studies of teen weight-loss approaches have centered on more intensive and heavily monitored interventions, sometimes in in-patient settings, the researchers note.
The other thing Nguyen's group did differently is that half of the kids also received text messages, emails and phone calls to follow up and coach them through the program.
"That's the direction a lot of people are going. And it makes sense, teens are plugged in," said Jelalian, who was not involved in this study. "Unfortunately, it didn't look like that added anything to their findings."
After the 12 months there were no differences in weight loss, cholesterol levels, mental health and behavioral measures between the two groups.
"It is possible that the (additional contact) provided was too mild and that participants could have benefited from more frequent, intensive contact," Nguyen wrote in an email to Reuters Health.
She added that the results don't prove that coaching through texts or emails is ineffective, and future research should look at whether more frequent contact could help make a difference.
There were positive differences between where the teens started out and where they ended up, the researchers point out.
The kids had lower cholesterol and triglyceride levels at the end of the year as well as higher scores on measures of self worth, academic and athletic abilities, and social acceptance.
On average, the kids actually gained weight -- which isn't necessarily surprising, given that they grew more than an inch during the study period.
To account for this, the researchers looked at changes in the kids' body mass index (BMI), a measure of weight relative to height.
After adjusting for a child's age and sex, the researchers found a slight drop in BMI after 12 months, indicating that the kids were shifting toward a more normal body size, although they were still overweight.
Jelalian said it's important to try new approaches to getting overweight and obese kids to lose weight, because research has typically focused on adults or younger children.
"There are some developmental considerations for adolescents that are unique," she said, such as the onset of puberty and a growing independence from parents.
"There are few other programs for this age group and that are sustainable in community-based settings," Nguyen said. "We know of no others in Australia that have been tested in research studies."
She said she would definitely recommend Loozit for overweight teens. And that her team is following up with a study on the results of the full 24 months of the trial.
So far, "These findings highlight the potential benefits of a low intensity weight management program targeted at adolescents that is sustainable in community settings," Nguyen and her colleagues write in their report.
SOURCE: http://bit.ly/yuGsmr Archives of Pediatrics & Adolescent Medicine, February 2012.