According to recent estimates by the Centers for Disease Control and Prevention, nearly one in five children in the United States is affected by obesity. Research has shown obesity often begins in infancy, emphasizing the need for early intervention strategies to prevent long-term health consequences such as cardiovascular disease.
A study co-led by Eliana Perrin, Bloomberg Distinguished Professor of Primary Care in the Department of Pediatrics in the School of Medicine and the School of Nursing, used an innovative approach that combines health literacy-informed counseling in pediatric clinics with asynchronous digital interventions to support healthy growth over the first two years of life. The study, known as the Greenlight Plus Trial, tested the impact of adding an automated digital intervention—interactive text messaging and a web-based dashboard to deliver personalized health behavior guidance—to traditional pediatric counseling for parents of children from birth to age 2. The text messages—which tried to get children to drink water and milk instead of juice or soda and encouraged physical activity and discouraged screen time—allowed for goal-setting, self-monitoring, and immediate feedback and tips based on goal progress. The dashboard enabled parents to track goal progress, monitor their child's weight and length, and access intervention content.
Image credit: Courtesy of Eliana Perrin
The results of the study were remarkable, with the digital intervention leading to significantly healthier weight-for-length trajectories and a substantial reduction in obesity rates at age 2. The intervention was shown to be effective across a diverse population, including groups at elevated risk for childhood obesity.
"These results were a really big deal," Perrin says. "We found that the intervention reduced childhood obesity from a rate of about 13% to a rate of about 7%, which is a relative reduction of about 45%! Ours was the first multisite intervention that resulted in the primary prevention of obesity in a diverse group of children ever, suggesting a huge potential for impact if implemented on a larger scale."
By leveraging mobile technology to provide accessible, personalized guidance for families, the Greenlight Plus Trial reflects a shift toward scalable solutions that can reach diverse communities and reduce health disparities, and presents an opportunity to rethink how pediatric care can combat early health inequities. Perrin has been awarded a grant by the Patient-Centered Outcomes Research Institute to continue this work and follow the same cohort of children until early school age.
Perrin recently spoke with the Hub about the study's results and its significance for addressing childhood obesity.
Why have childhood obesity rates increased so dramatically in the United States over the past several decades?
While we don't know exactly why, we do have some theories. Children are eating more (bigger bottles, bigger plates, larger restaurant portions), and what they are eating is more calorie-dense and nutrient-poor. We live in what Kelly Brownell has called a "toxic food environment," and it hits children hard. Children also get less physical activity in their usual lives—there's less outdoor play, less walking or biking to school, less recess, and less time in after-school sports. And, finally, they watch more screens and see more advertising of unhealthy foods and drinks.
What are some common misconceptions about childhood obesity that you encounter in your research or clinical practice?
The misconceptions are that children with obesity are less smart or lazy. There are also misconceptions that children will always outgrow their obesity, and we shouldn't be concerned when young children have overweight or obesity. In fact, childhood obesity tracks really well, and, unfortunately, over 80% of children with obesity at age 3 never outgrow it.
What inspired the idea to incorporate a digital intervention into traditional health behavior counseling?
We did a study several years ago to try to prevent young children from becoming overweight by having pediatric providers work with parents at every well-child checkup from 2 months of age through 2 years of age, and we thought we did everything right. And it worked … sort of. That pediatrics office intervention (called the Greenlight Intervention Study, which we affectionately called "Greenlight 1.0") prevented children from becoming overweight at age 4, 6, 9, and 12 months, but unfortunately, by 24 months, the children who got the intervention had the same rate of obesity as the children who didn't. We asked ourselves, "Why would it work early on but not later?" And then it hit us: Children go to the pediatrics office a lot in that first year of life (at 2, 4, 6, 9, and 12 months), so they got lots of "doses" of that intervention. But they don't go much in the second year of life. In fact, there's no checkup at all in between 18 months and 24 months. And then parents are on their own a lot of the time—there's no pediatrics provider to check in with when they are at home feeding their kids. We realized that we need something asynchronous to office visits. We need to provide counseling in a different way altogether—texting was that different way to provide guidance. So we came up with the Greenlight Plus study, offering texting outside the office in addition to the counseling in the office.
Your study focused on the first 24 months of a child's life. How significant is this early period for preventing obesity, and why is early intervention so critical for long-term health outcomes?
That early period is everything! That's when children learn critical habits: water for thirst quenching, starting with small portions and then seeing if you are hungry for more, not getting used to watching screens or eating junk food. In those first couple of years of life, parents ask a ton of questions about how to feed children and what safe exercise there is. And then there are answers to the questions they don't know to ask. One parent once told me about her 4-year-old, "I wish we'd never started the juice habit. No doctor ever told me not to give him juice. Now he's hooked, but it would have been easier not to start in the first place." Our intervention is all about not starting some of these unhealthy habits in the first place so children can grow up healthier. We know from some of our other research that when children drink sweet beverages early on, they drink more sweet beverages later. When they watch TV early, they watch more TV later. We also know that when children have obesity early on, they are more likely to have obesity and severe obesity later, so prevention in those first couple of years is really very important.
The study showed a reduction in weight-for-length trajectories and obesity at 24 months. What do these findings suggest about the long-term potential of early digital interventions?
Ours was the first multisite intervention that resulted in the primary prevention of obesity in a diverse group of children, and it actually worked best for groups thought to be at highest risk for obesity. And there is pretty good potential to do this at scale for not all that much money. The return on investment would be huge! These findings bode really well for the long-term potential of early digital interventions. But of course, more work needs to be done on that score to really know the broader impact for other interventions like this one.
The study found that the intervention had a stronger effect on children from households with food insecurity compared with others. Why do you think that is?
We don't know for sure, but we hypothesize that our intervention taught families that they didn't need to give as much food to children as they feared. A lot of parents worry that they are not giving children enough food. Parents with food insecurity may especially worry about this, and some parents have told us this in other interview studies. So when our intervention advises parents to feed portions the size of their children's fists, that helps them avoid overfeeding and eliminates feelings of guilt—all at the same time.
How do you hope these findings will impact pediatric care?
Well, pediatric providers know that childhood obesity is affecting lots of children and causes lots of chronic health problems, but many feel helpless because of an unhealthy environment and so little in-office time to address this with counseling. This intervention allows for all the important counseling to occur—but much of it outside of the office—so that office time can be spent on so many other important areas. We are hoping to do studies to implement Greenlight Plus more widely into practices nationwide, and from our queries to date, we know pediatric providers are very enthusiastic.
How do you envision the future of childhood obesity research?
I really hope that we can spend more time on three things: changing policies toward improved physical activity, less advertising of unhealthy products, and healthier dietary practices; prevention of childhood obesity and other chronic diseases rather than only spending money on reactive treatment; and improved primary care for all, which helps us set a healthier foundation for a healthier America.
