The study highlights the importance of making the battle against obesity a family matter, since Morton said previous research has suggested that obesity is a social contagion, meaning that associating with an obese person is more likely to lead to obesity.
"Obesity is a family disease," said Morton.
"This study tells us that individual intervention is not going to be successful, especially with children, so we have to target whole families," said Dr. Mitchell Roslin, chief of obesity surgery at Lenox Hill Hospital in New York.
Morton said more research is underway to determine the effects of bariatric surgery on families over the longer term, results other experts are eager to see.
"These operations can get anybody to lose weight, but without education and diligence, there will be a high recidivism rate," said Roslin. In turn, this could lead family members to re-gain weight as well.
Roslin also said it's important to remember that the effects may not be the same among people of different ethnicities and socioeconomic statuses, so this same sort of family-targed intervention may not be as effective.
The adult family members in the study, de la Cruz-Munoz added, only lost a minimal amount of weight although it was scientifically significant. But, he said, the fact that they introduced healthier behaviors is an encouraging finding.
More than a year later, Caitlin Dunnings is only about 13 pounds away from her target weight and her mother is also getting closer to her goal. The family's eating habits have totally changed, and Caitlin is confident her father and brother can continue with their non-surgical weight loss.
"We have great family support. They like the energy we have now and they want more energy. They see how happy we are and they're keeping it up."