Prevention of Obesity in Early Childhood: What Are the Next Steps?

Despite increased awareness and intensive intervention efforts for two decades, childhood obesity has remained a significant public health issue. An analysis of the National Health and Nutrition Examination Survey indicates that the prevalence of obesity in children aged two to five years has increased significantly from 2013–2014 to 2015–2016.¹ These data are surprising, especially when framed within the context of Michelle Obama’s Let’s Move campaign, as well as the many initiatives promulgated during this period. Many obesity-prevention programs have recently focused on preschool children, because the trajectory for obesity has been shown to start early in life.

The study published by French et al. (p. 1695) highlights results from a three-year obesity-prevention trial conducted in preschool-aged children, Now Everybody Together for Amazing and Healthful Kids (NET-Works). Despite a robust approach, which included a behaviorally based multisetting and multicomponent program, French et al. found no significant differences in body mass index at 24 or 36 months among intervention children compared with control children, although there were significant results in some a priori subgroup analyses. What lessons from this study could guide researchers and practitioners in increasing the efficacy of the next generation of early childhood obesity-prevention interventions?

DOSE IS IMPORTANT

One important takeaway from the NET-Works study was that many families did not receive the intended dose of the intervention. In this study, dose is the family’s exposure to the intervention, which was measured by the number of contacts or classes attended; this measure may also be a proxy for family motivation or barriers that interfere with attendance. Components of the intervention included parenting classes, home visits, and check-in calls, but dose ranged from 25% attendance for parenting classes to 58% for check-in calls.

Dose has been found to be significantly associated with outcomes in child obesity-prevention interventions. For example, our recent work has shown that a change in the percentage of body mass index at the 95th percentile in children enrolled in an intensive community-centered weight maintenance program was inversely related to compliance.² The dose to achieve this effect was larger with preschool children compared with children aged six to eight years and nine to 12 years (70%, 50%, and 20% attendance, respectively).

If intervention dose is important, especially among younger children, then the field should focus on increased program implementation as well as outcomes. Behavioral factors and motivations that underlie parent participation in obesity-prevention interventions should be examined, with dose as an additional study outcome or effect modifier in the analysis. Using implementation science to determine novel modes of delivery for interventions can possibly yield important insights.

CONSIDER ENVIRONMENTAL FACTORS

Although the NET-Works intervention did focus on home, community, and provider settings, other environmental factors were not addressed. For example, the early care and education environment (e.g., Head Start Centers) was not targeted. As with schools, early care and education sites offer an environment that can provide health promotion for parents and children, as well as reinforce healthy behaviors through cues to action, teacher–parent communication, and setting norms for diet and physical activity. Creating training opportunities for early care and education teachers in nutrition and physical activity can reinforce healthy behaviors in children and strengthen implementation of health-promotion programs. Recent work has shown promise for implementation of obesity-prevention programs in Head Start Centers.³

Other environmental influences include mass media messages around healthy eating and active play and the availability of healthy foods and safe opportunities for play. Despite advocacy work and industry self-regulation to counter food advertisements on children’s television, commercials still promote predominantly unhealthy food.⁴ Many restaurants are promoting healthy options, but “kid foods” that consist of high-fat and high-sodium entrees such as hamburgers and pizzas are still featured and can potentially contribute to parental norms that focus on a few highly palatable foods rather than introducing children to a wider variety of healthy options. Finally, the lack of safe play areas can decrease physical activity opportunities for preschool children. It could be that these external environmental factors are so pervasive that they counter or overwhelm more focused community-based interventions.

FOCUS ON FAMILIES

The NET-Works study did find significant obesity-prevention effects among Hispanic children and those who had overweight and obesity, results similar to what we have observed in school-based studies.⁵ Community- and family-based interventions seem to be particularly resonant for Hispanic and Latino families, perhaps because this type of programming is consistent with cultural norms of familismo, the importance of and obligation to the extended family. Unfortunately, many preschool interventions do not or cannot incorporate family involvement, which is expensive because of the need to provide program components and resources for the entire family. In addition, when low-income families are involved, programs need to include flexible scheduling, babysitting for younger siblings, travel assistance, and provisions for liability insurance for extended family members who might want to participate, many of which were features of NET-Works.

Most of the parents (∼ 75%) in NET-Works were overweight or had obesity, suggesting that intervention strategies aimed at the parents concomitantly with the children might have been useful. Programs that are framed in a family systems approach and incorporate skills training, such as family culinary nutrition classes, could provide activities and intervention targets that address obesity prevention and weight maintenance in both parents and children.

SOCIODEMOGRAPHIC FACTORS PROVIDE CONTEXT

Although approximately 72% of the NET-Works population lived in dual-parent homes, more than 62% had annual household incomes of less than $25 000, with 67% reporting participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and 43% reporting participation in the Supplemental Nutrition Assistance Program (SNAP). More than 30% reported being food insecure, and another 6.3% reported being food insecure with hunger. In addition to the multiple stressors inherent in poverty, these data imply the importance of providing healthy foods and evidence-based nutrition education through WIC and SNAP-Ed. Consistent messaging through food-assistance programs can help to reinforce messages for healthy eating and active living.

EARLY CHILDHOOD OBESITY-PREVENTION CHALLENGES

In comparison with school-aged children, preschool children can often be difficult to reach for public health interventions, because care can take many forms: center-based care, daycare homes, or care with a parent or relative. The primary care setting can be another venue to reach preschool children, because well-child checks are scheduled consistently during the first six years of life. Obesity-prevention programs in or as an adjunct to the primary care setting can emphasize responsive parenting practices to prevent obesity. Because many parents do not perceive excess weight to be a health issue in their preschool child, providers can be instrumental in screening and providing brief counseling to families, as well as referrals to community resources that support healthy behaviors. Another option might be to focus on parenting skills during the prenatal period. A recent study by our group found that low-income pregnant women participating in a pilot study implementing an obesity-prevention program reported improvement in obesity-related behaviors.⁶

CONCLUSIONS

Lessons learned from NET-Works (French et al., p. 1695) and other recent obesity-prevention and weight-maintenance studies in low-income children^2,3 indicate the importance of ensuring adequate dose and implementation of programs, focusing on environmental and sociodemographic risk factors, including families in intervention efforts, and promoting consistent messaging within food-assistance programs and physician offices. In addition, obesity-prevention efforts should consider starting interventions during the prenatal period to instill healthy behaviors from birth to protect the littlest members of our society from increased risk of obesity.