Abstract
Abstract
Background:
Early childhood is a formative period for many weight-related behaviors (diet and activity), but little obesity prevention research targeting this age group has been conducted. Early care and education settings are a useful avenue for interventions targeting young children, but the limited research provides insufficient evidence upon which to base policy decisions, practice guidelines, or mobilized efforts to improve healthy eating and physical activity, and ultimately healthy weight development in these settings.
Methods:
In September of 2011, prominent researchers, young investigators, and leaders in early care and education came together to examine past research and to explore challenges and priorities for future research on healthy weight development in children aged 2–5 years. During this meeting, experts presented and attendees discussed key issues around measurement of diet and physical activity, policy and environment measurement, intervention approaches, policy research, and capacity development. Following the meeting, attendees were invited to participate in an online voting exercise to select top research priorities.
Results:
A total of 64 research issues were identified, and voting narrowed this list to 24 issues. Highest-rated issues included: Assessment of the quality of children's meals and snacks, use of financial incentives, interventions that include healthcare providers, the role of screen time, and need for multilevel interventions.
Conclusions:
The presentations within this meeting highlighted the importance of research to address the unique challenges for those working in early care and education settings. Expert and stakeholder consensus of priorities identified significant and innovative areas where future obesity prevention research efforts should be focused.
Introduction
Recent national data (National Health and Nutrition Examination Survey 2009–2010) indicate that one in four children aged 2–5 years are overweight or obese, 1 thus increasing their risk of becoming overweight and obese adolescents and adults and incurring long-term health problems. 2 Early childhood is a critical period in obesity development,3,4 and therefore, an important target for healthy eating and physical activity interventions to establish healthy weight gain trajectories.
Early care and education (ECE) programs are important settings for obesity prevention. 5 Child care centers and family child care homes account for a large portion of early care and education programs in the US, providing care for an estimated 30–40% of children under the age of 6 years.6,7 Children spend, on average, 30 hours per week in these settings. 6 Thus, ECE programs and their staff play a central role in developing children's health behaviors and reducing their risk for obesity by shaping the physical and social environment in which they eat, sleep, and play.
Nationwide, public and private organizations are working to encourage adoption of policies for ECE programs that promote healthy eating and physical activity. Two of the most significant examples of recent authoritative reports are Caring for Our Children's Preventing Childhood Obesity in Early Child Care and Education Programs 8 and the Institute of Medicine's (IOM) Early Childhood Obesity Prevention Policies. 9 Caring for Our Children focuses on best practices in nutrition, physical activity, and screen time for all types of ECE settings, whereas the IOM report examines the evidence and provides guidance on obesity prevention policies for children up to 5 years of age.
Growing support from the public health sector for ECE-based obesity prevention efforts has highlighted the need for more research in this area. A 2011 systematic review of obesity prevention studies in child care settings found only 18 intervention studies, all of which had been published since 2003. 5 Reviews by Hesketh and Campbell of obesity prevention studies in children 0–5 years old have documented the rapid increase in published intervention studies in both the United States and other developed countries in recent years. Although their 2006 literature search identified only two ECE-based intervention studies, 4 years later an additional seven studies had been published.10,11 Despite increased interest, these recent reviews highlight both the nascency and dearth of obesity prevention research in ECE settings. Clearly, more studies are needed because a strong research foundation is essential to identify and support evidence-based practices and policies that can be implemented at federal, state, and local levels.
In the fall of 2011, a multidisciplinary group of experts met to identify and prioritize research directions for obesity prevention in ECE settings that would: (1) Identify policy, environmental, and behavioral measures related to food, nutrition, and physical activity, as well as media use at ECE settings; (2) suggest promising study designs for intervention and policy research that would enhance the quality of the nutrition and physical activity environments in ECE settings; and (3) enhance the development of early career researchers and researchers from diverse racial and ethnic backgrounds. Conference funding was obtained largely through the NIH's National Heart, Lung and Blood Institute (NHLBI) and Office of Behavioral and Social Sciences Research (OBSSR), with additional support from the Robert Wood Johnson Foundation's (RWJF) Healthy Eating Research and Active Living Research programs, the Nemours Foundation, and the Altarum Institute. The purpose of this article is to report the research issues and priorities identified during this meeting.
Methods
A planning committee, made up of individuals with extensive knowledge of obesity prevention, nutrition, physical activity, and child care, was formed under the guidance of authors (D.W. and M.S.) to help to identify potential topics, speakers, and invitees. The meeting was held in Arlington, Virginia on September 26–27, 2011, with 43 participants, including faculty from a variety of universities, representatives from multiple foundations interested in child obesity prevention, delegates from multiple branches of the NIH and the United States Department of Health and Human Services, and other key leaders in ECE (available upon request). The program was organized into four sessions: Introduction and overview, measurement-related issues, intervention approaches, and policy. Following these four sessions, attendees divided themselves into roundtables to discuss research gaps related to the following five areas: Diet and physical activity measurement, policy and environmental measures, intervention design, policy research, and capacity building. Each roundtable was responsible for generating a list of important research issues deserving further work and investigation within their specified topic area. Project staff members were present during all sessions, including roundtable discussions, to take notes and capture details around the issues raised. Presenters' PowerPoint slides and staff notes were compiled to create a summary of the current knowledge and key issues in each session. Summaries were reviewed by authors (D.W., M.S., and A.V.) who had attended all sessions. The list of research priorities drafted by each roundtable was compared against staff notes to ensure that each recommendation had been clearly captured (available upon request). After the meeting, an anonymous survey with this compiled list of priorities was distributed by email to all attendees. This list of priority research areas was subdivided into five categories (11 subcategories): Diet and physical activity measurement (general measurement issues, diet specific issues, and physical activity specific issues), environment and policy measurement, interventions (general intervention strategies, community-level strategies, organizational-level strategies, interpersonal-level strategies, and individual-level strategies), policy research, and capacity building. Within each category (or subcategory), participants were asked to choose the three to five recommendations that they felt were the “highest priority,” and to rank each one selected on importance (high to low). A weighted score was created within each of the five areas (frequency of selection and level of importance), and a priority score was calculated as the percentage of the maximum score possible (e.g., weighted score/maximum score).
Results
Current Knowledge and Key Issues for Future Research
Measurement of Child Diet and Physical Activity Behaviors
Speakers reviewed the best available methods for assessing child diet and physical activity in ECE settings, including the strengths and weaknesses of each method and issues for future research (summarized in Table 1).
Measuring Child Diet and Physical Activity and ECE Programs' Policies, Practices, and Environment
Weighed or measured intakes, meal observations, and plate waste were presented as methods that provide a reasonable estimate of child food intake. Generally, methods with greater precision are also more susceptible to subject reactivity and are more expensive to implement. Therefore, researchers must balance the very practical issues associated with data collection and cost with the research needs and goals. Future research would benefit from the development of technology that would allow for an objective assessment of child diet (similar to how accelerometers provide an objective measure of physical activity). To facilitate comparison of findings across studies, researchers also need to build consensus around use of a standard and valid measure of child diet that evaluates both quantity and quality of intake.
Accelerometers, direct observation, and proxy reports are commonly used methods for assessing child physical activity. Accelerometers are often viewed as the gold standard because they provide an objective assessment; however, there remain issues around data reduction and interpretation. Before the field has even reached consensus regarding appropriate cut points for preschool age children, new analytic approaches (e.g., pattern recognition) are being proposed that have yet to be applied to data from preschool age children. Although there are many issues around how to measure physical activity, another critical subject for future research is to determine the most appropriate physical activity behavior to measure in young children. Children have different activity patterns compared to adults, which may make adult-oriented outcomes of moderate-to-vigorous intensity physical activity less suitable as a primary outcome for studies involving preschool-age children. Inclusion of all nonsedentary intensity levels (light, moderate, and vigorous) may be more appropriate for this age group.
Attendees underscored the need for best-practice guidelines and enhanced assessment methods. Best-practice guidelines for diet and physical activity assessment in ECE settings should provide clearly defined behavior targets to measure, guidance for selecting appropriate tools/methods, advice for data reduction and interpretation, expected intraclass correlations in diet and activity of children within a center, and the number of children needed for reliable assessment of diet and activity. Desired enhancements for diet and physical activity assessment methods included integrating measures of diet and physical activity behavior with environment; adding assessments of the sociocultural environment, provider behaviors, and knowledge; and developing methods appropriate for use with children 0–2 years old.
Measurement of Child Care Policies and Environment
Speakers reviewed the few existing assessments of ECE food and physical activity environments and policies, highlighting just how new this area of research is and the many issues that still need to be addressed (summarized in Table 1). As with the assessment of child diet and physical activity, selecting an instrument is often a balance between data quality, cost, and feasibility.
Instruments like the Environment and Policy Assessment and Observation (EPAO) 12 and the Wellness Child Care Assessment Tool (WellCCAT) 13 have published evidence of reliability and validity, but they require intensive training and access to instruments and training protocols that are not freely available. This restricted access is due in part to the desire to maintain the quality with which these protocols are implemented. Attendees expressed the need for both enhancements to and simplification of existing instruments. Those promoting enhancement wanted refinement of items assessing complex constructs (e.g., pressuring children to eat, using responsive feeding practices, serving meals family style) to add clarification and more concrete examples of what these behaviors look like, so those reporting or collecting data can accurately assess them. Additionally, those using instruments to evaluate the impact of a new policy or program wanted to be able to evaluate possible moderating variables, such as effectiveness of training efforts, caregivers' willingness to adopt new practices, and perceived barriers to adopting new policies. There was also a call for these intensive and costly assessment methods to be translated and simplified to facilitate use by others. As part of this translation process, researchers need to explore how well these instruments evaluate compliance of child care programs with best-practice guidelines for nutrition and physical activity.
Child Care–Based Interventions and Policy Research
Additional child care–based obesity prevention interventions are needed to build a research base that will support creation and adoption of evidence-based policies. However, the child care–based intervention studies conducted to date provide many lessons to guide future research efforts (summarized in Table 2). A 2011 systematic literature review identified only 18 child care–based interventions that targeted nutrition, physical activity, and/or obesity prevention. 5 While many were able to demonstrate intervention effects on behaviors, only two of the five assessing weight outcomes showed positive effects. Future interventions should employ multilevel strategies and explore how to use child care programs as access points to help create linkages to families, pediatricians, and other sources of support. Minority populations (African Americans, American Indians, Hispanics), which suffer disproportionately high rates of obesity, are important targets for future interventions; however, such efforts must be culturally tailored to meet the needs of these populations. New frameworks and behavior change theories, such as the Behavior Change Wheel, 14 should be used to inform intervention development, and researchers may need to look beyond their immediate field for potential frameworks and behavior change theories to employ. Future intervention and policy research would also benefit from consensus that traditional study designs and outcome measures may not be appropriate for this age group and setting. In intervention studies, high turnover rates of children make the traditional cohort design impractical. And, policy research often requires the use of natural experiments. Traditional weight outcomes (e.g., BMI) are more difficult to interpret given children's natural growth and adiposity rebound at this age, yet there is no agreement on an alternative strategy. Future studies would also benefit from inclusion of measures of cost effectiveness and monitoring for unintended consequences to guide adoption of the most efficient policies and programs.
Issues for ECE-Based Interventions and Policy Research
Research Priorities
Sixty-four research issues were identified during roundtable discussions across five areas—diet and physical activity measurement, policy and environment measurement, interventions, policy research, and capacity building. Among the 43 conference participants, 44% completed the follow-up on-line survey to identify research priorities. Twenty-four of the research issues received a priority score of 40% or greater (listed in Table 3). Research areas receiving the highest scores within each of the categories were as follows:
Research Priorities for Early Care and Education
Abbreviation: ECE, early care and education.
• Measurement of child diet and physical activity. Assessment of the quality of children's meals and snacks received the highest score across all categories, at 74%. In addition, enhancement of measures for children 0–2 years old, development of reliable and valid measures of provider behaviors around diet and activity, use of technology to create an objective measure of diet intake, and use of pattern recognition approaches with accelerometer data all received scores>50%.
• Measurement of policy and environment. Development of a standard rating system for nutrition and physical activity policies was the only issue receiving a score>50% in this category.
• Interventions. Use of financial incentives, interventions that include healthcare providers, role of screen-time, and need for multilevel interventions all received scores>60%.
• Policy. Evaluation of the effectiveness of state-level policies and standards and evaluation of the cost-benefits associated with policies received scores>50%.
• Capacity building. None of the issues received scores>50%.
Discussion
The meeting was very productive in identifying the key issues related to measurement strategies, intervention design, and policy approaches for obesity prevention research in ECE settings. Themes that emerged repeatedly across sessions included the need for evidence-based policy approaches, funding challenges, and selection of the most appropriate outcomes and how to measure them. It was pointed out that the recent IOM committee report on Early Childhood Obesity Prevention Policies 9 presented “evidence-informed” recommendations, because there is an insufficient evidence base on obesity prevention in child care settings. The childhood obesity crisis has driven many states to adopt policies they hope will have a positive impact on nutrition and physical activity at child care; however, many of these policies are untested. They may have no impact, or even worse, unintended negative consequences. While this rapidly changing environment may give us pause, it also provides unique opportunities for natural experiments of which researchers should take advantage.
Current funding mechanisms present a challenge to building this evidence base. Obtaining funding using an NIH mechanism can easily take 2 years or more from the time the project is conceptualized until receiving notice of the award, and only the top 5–12% of grant applications receive funding. Foundations can provide an alternative funding channel; however, these grants are generally smaller and shorter in duration. Assessing the long-term impact of child care–based obesity prevention interventions requires following these young children into adolescence and adulthood, neither of which is likely in the current funding environment. Evaluating the long-term effectiveness of new policies and programs is critical and researchers in the United States and abroad have been struggling to address this issue. 15
There is also great interest in how we define the target behaviors and outcomes measured to evaluate the impact of interventions and policies. Traditional outcome measures of diet (kcal/day) and physical activity (minutes of moderate to vigorous physical activity) are not always appropriate for children under 5. This is a period of rapid growth and development, and a child's caloric intake will be influenced by these growth spurts. Young children's physical activity looks very different from that of adults. Given children's intermittent activity patterns, perhaps a more appropriate behavior to target may be providing opportunities for active play, and a better outcome to measure may be minutes of nonsedentary time. Physical activity guidelines for early childhood from the United Kingdom, Canada, and Australia all emphasize limiting sedentary time or promoting nonsedentary time in their recommendations for this age group.16–18 In addition to measures of weight, nutrition, and physical activity, researchers should also consider incorporating target behaviors and outcome measures related to other developmental outcomes such as academic performance, cognitive ability, or quality of life. Most studies to date incorporating these outcomes have been conducted in school-age children and have shown that overweight and obese children are more likely to have lower test scores, academic performance, and cognitive functioning compared to children who are normal weight.19–22 These poor education outcomes may be due in part to more missed school days and greater behavior problems, both of which have been associated with child overweight.20,21,23 Positive findings from such cross-disciplinary studies help facilitate partnerships between professionals in public health, child development, and education, which in turn would strengthen the advocacy for disseminating obesity prevention programs and policies.
Conclusions
Creating environments that promote healthy eating and regular physical activity before children develop poor habits is critically important for obesity prevention; however, research in ECE settings is in its infancy. This gathering of research experts, leaders from national health agencies, and ECE professionals used a conference format to hear 10 experts describe significant research issues in the areas of diet and physical activity measurement, measurement of environments and policies at ECE settings, intervention and policy research, and addressing children from minority families. Through careful recording and transcribing of all discussions during the conference, as well as the final roundtable process, 64 research gaps in this area were identified. After the meeting, participants completed an on-line voting survey that allowed for the further identification of 24 priority research areas that included diet, physical activity, environment/policy measurement, intervention development and evaluation, policy research, and capacity building.
Efforts are needed to encourage funders, both federal agencies (such as NIH, CDC, and USDA), as well as foundations (RWJF, American Health Association, and others) to understand the importance of early care and education settings as critical in the fight to address obesity prevention as early as possible. Further research in this area will help identify the most promising interventions and strategies to promote healthy eating and physical activity in child care settings.
Footnotes
Acknowledgments
This project was funded by the NIH's National Heart, Lung and Blood Institute and Office of Behavioral and Social Sciences Research (1R13HL108431), the Robert Wood Johnson Foundation's Healthy Eating Research and Active Living Research programs, the Nemours Foundation, and the Altarum Institute. The work was also supported by the University of North Carolina's Center for Health Promotion and Disease Prevention, a member of the Prevention Research Centers Program of the CDC (#U48-DP000059). The content is solely the responsibility of the authors and does not necessarily represent the official views of the CDC.
This work would not have been possible without the great contributions of all those who participated in this conference. Special appreciation to those who presented and led discussions, including Barbara Dennison, Lori Beth Dixon, Lisa Harnack, Kathryn Henderson, Robin McKinnon, Sara Benjamin Neelon, Angela Odoms-Young, Russell Pate, Lorrene Ritchie, James Sallis, Marlene Schwartz, and Stewart Trost.
Author Disclosure Statement
No competing financial interests exist.
