"Childhood obesity is a serious public health issue in developed and in developing countries and we need to set the course as early as possible," Hannah Ewald told Reuters Health in an email.
Ewald, the study's lead author, is a researcher at Warwick Medical School in Coventry, UK.
"Being chronically ill can be a heavy burden but the physical aspect is just one side of the coin," she said.
"When I see overweight children being teased for their weight, when I see them panting instead of laughing when chasing each other around on the playground or when I see look in their faces - it always gives me a sting."
Utilizing a parent-only approach to address kids' weight might be cheaper and less embarrassing for children, David Janicke told Reuters Health in an email.
Janicke, from the University of Florida in Gainesville, has studied parent-only interventions for childhood obesity but was not involved in the new review.
He said parents might also find it easier to focus on and participate in a program without the child present.
The researchers reviewed papers on eight prior or ongoing studies. In all of the studies, families of overweight and obese children were randomly assigned to different weight-loss interventions.
Five of the studies compared group programs for parents with interventions targeting both parents and kids. Two compared parent-only to child-only interventions. In the remaining study, some of the parents and their children met separately and then together.
Programs for parents included diet and nutrition education, plus information on physical activity.
The parent-only interventions were at least as effective in promoting weight loss among kids as the combined parent-child interventions, if not more so, according to findings published in the Journal of Public Health.
However, more families dropped out of the parent-only interventions.
Ewald's team suggested that could be due to parents feeling overwhelmed by taking on the responsibility of their children's weight problems.
But Janicke said parents are put in charge of their children's health in parent-child weight-loss programs as well.
"In gold standard behavioral family interventions that include children with their parents, the parents are taught to utilize the same skills as parents in the parent-only interventions and are still encouraged to take primary responsibility for making family wide changes," he said.
"A child that is given the sole responsibility for its weight is unlikely to succeed in gaining a healthy weight," Ewald said. "How to eat healthy, how to exercise properly and how to deal with the emotional side are difficult topics to tackle even for adults. That is why the parents (or caregivers), who have the biggest impact on the child, need to understand their part in the process."
The results should be interpreted with caution, the researchers said - in part because most of the studies they looked at were small.
Janicke said he isn't aware of any clinics or organizations that currently take a parent-only approach to children's weight loss.
"One potential challenge to these programs is that in my experience with our intervention research studies, some parents are hesitant to sign-up for programs or treatments in which their child does not attend the program with them. Some say that they want their child to be able to socialize with similar children," he said.
"Other parents have expressed that they cannot get their child to change, and they want their children to learn about making lifestyle changes from professionals," Janicke said.
"From our experience, once parents attend the parent-only programs, they have been very happy with the process and outcomes," he said.