Many authors have documented aspects of the obesity epidemic as it has spread across the United States.1·2 The associated rise in obesity-related comorbidities is also well established.3 Direct annual healthcare costs associated with obesity have been estimated to total $92.6 billion, or approximately 9.1% of national health spending.4 Research continues to evaluate the causes of overweight at the genetic, molecular, cellular, behavioral, and societal levels.
At the same time, many researchers endeavor to develop effective treatments through pharmacologic, surgical, clinical management, or other therapeutic approaches. "While mese "investigations must continue, there is a clear and immediate need for overweight prevention efforts to be developed and implemented on a large scale.
An ecological model applicable to overweight prevention
The rationale for prioritizing pediatric overweight prevention efforts is based on many factors. First, early and effective prevention would spare at-risk children from accumulating the numerous and significant co-morbidities associated with overweight.5 Second, the developmental and psychosocial issues correlated with pediatric overweight, such as early menarche, diminished quality of life, and subjection to bullying and prejudice, might also be prevented with early intervention.6"9 There is evidence that healthy behaviors initiated and ingrained in childhood often persist into adulthood, such as a commitment to regular physical activity.10 Further, knowledge and experience gained from previous public health efforts designed to prevent substance use, injury, and risky behaviors have shown the effectiveness of focusing on youth.
The pediatric overweight epidemic poses an extremely complex public health challenge, requiring the effective use of many types of resources - human, financial, physical, and political - that can be used in a variety of ways. For example, pediatricians have an essential role to play in clinical practice and advocacy at the individual, family, community, and societal levels.11 Urban planners and policymakers also need to be engaged at the community and societal levels.12 The efficient allocation of these roles demands a comprehensive strategy.
AN ECOLOGICAL MODEL FOR OBESITY PREVENTION
Davison and Birch13 have proposed an ecological model that conceptualizes the relationships among overweight risk factors. A highly simplified version of this type of model is presented in Figure 1. Barriers to overweight prevention exist at each of these levels, and prevention efforts focused on any one level are likely to fail without simultaneous, complementary, and supporting work at each of the other levels.
This means, for example, that prevention or treatment of overweight in a young child requires the child's family to undertake changes in diet and activity. If families are to sustain such changes, the community in which they live must provide them access to healthy foods and opportunities for physical activity. For communities to gain or deliver the resources needed by families, the broader society must retreat from its promotion of junk food and car travel. The opposite is likely also true; to be successful, national media campaigns promoting physical activity and nutrition must be connected to community-based resources providing families and individuals accessible opportunities to lead healthy lives.
No single agency or organization has the resources, expertise, community ties, political connections, incentives, and ambition to take on every necessary task. Broad trans-disciplinary partnerships are needed, with a coordinating infrastructure. Collaborative efforts ideally include groups that do not routinely work together, such as pediatricians and bicycle advocates, urban planners and school nurses, and the local health agency and a vending machine company.
Regardless of the exact details of the partnership, some aspects must be centrally organized and coordinated. Data collection across organizations or communities should be standardized whenever possible. Information on relevant outside activities, current or developing best practices, consortium-wide events, and notice of available resources must be disseminated consistently and efficiently. The central infrastructure must act to facilitate and improve the effectiveness of each of the consortium partners.
The coordinating body can also promote common thematic foci, processes, and outcomes to be measured. All of these should reflect the current state of the obesity prevention literature, as well as local activity and needs. The choice of these can be guided by the "criticalperiods approach" to childhood overweight.14
Several critical periods in obesity development have been identified. In utero, matemal hyperglycemia has been associated with later childhood overweight.1516 Early and rapid weight gain in infancy increases the odds of overweight,17 while breastfeeding reduces those odds.18"20 Early childhood is a pivotal period because of the adipose rebound.2124 Adolescence again brings heightened risks for overweight and related comorbidities.25·26 Each critical period presents unique prevention opportunities and challenges.
The Consortium to Lower Obesity in Chicago Children (CLOCC) is a local overweight-prevention initiative that is being built in a manner consistent with the ecological model. The infrastructure for CLOCC resides within the Mary Ann and J. Milburn Smith Child Health Research Program at the Children's Memorial Institute for Education.
CLOCC was founded in January 2003 after a several month planning process. It is growing at a rapid rate, and consisted of over 320 participant groups and individuals by October 2003. It encompasses all of the work being done by its members to reduce childhood overweight in Chicago. Information is disseminated via a Web site (http://www.clocc.net), and by a quarterly newsletter and multiple email mailing lists.
CLOCC Organizational Structure
CLOCCs primary focus is prevention of childhood overweight during the critical early childhood period. Its main target audiences are at-risk children and their parents and caretakers; this is because this biologically critical period is also characterized by psychosocial features that facilitate promotion of healthy habits. Family dynamics dictate that children ages 3 to 5 only rarely determine family food choices or opportunities for physical activity. Young children are known to be eminently susceptible to the effects of parental role-modeling.27"29 Further, promoting healthy lifestyles for preschool-age children has broad political and social appeal.
CLOCC also facilitates work with older children and their families and caretakers. Similarly, while CLOCCs main focus is primary prevention, secondary prevention and overweight management issues are also a part of its work. The consortium's geographic mandate is limited to Chicago, but CLOCC is a resource to and partners with organizations and services beyond the city.
CLOCCs Organizational Structure
To fulfill its mission and achieve its process goals, CLOCC is organized as illustrated in Figure 2. Activities at the city and network levels are represented by the outer ring in this figure. Coordinated activities there are designed to foster collaboration. Open meetings are held quarterly to share knowledge and set collaborative priorities. Seed grants of less than $20,000 are awarded quarterly to promising projects that can forward CLOCCs mission.
Shared work by CLOCC members is conducted by six working groups (WGs), each with small independent annual budgets and self-defined priorities. The WGs are: Addressing Diversity, Clinical Practices, Data Surveillance, Governmental Policies and Programs, Non-Governmental Policies and Programs, and Research. Activity within any individual group usually is confined to that group, but information sharing among the WGs is facilitated by the executive committee (EC), which meets monthly to advise CLOCCs medical and executive directors. The directors lead the organization between EC meetings, assisted by research and office personnel. The external advisory board will meet near the end of CLOCCs first year to provide feedback and guidance.
CLOCCs coordinating functions are supported by core funding; large projects are developed as separate projects and submitted for external funding. CLOCCs first-year core projects have included inventorying of network resources, available local anthropometric and other data, and program evaluation approaches. A separately funded project, Transportation that is Active and Safe for Kids (TASK), is evaluating barriers to physical activity in four of Chicago's 77 community areas.
CLOCC has found Chicago is an excellent environment in which to apply its ecologie model. Scant available data indicate that Chicago preschool children experience a higher risk of overweight than predicted by national averages.30 There are many municipal resources, academic research centers, and active community-based and advocacy-focused organizations. Growing numbers of members in the government, business, and nonprofit sectors are taking leadership in promoting health-fostering messages and projects.
As part of its mission, CLOCC is committed to advancing the science of obesity and overweight prevention. It has already awarded pilot-project funding to implement a pilot overweightprevention program targeting preschool minority children. The program will evaluate physician perceptions and current practices to recognize and treat overweight children in a clinical setting, and complete environmental assessments that can help guide TASK'S work.
Another of CLOCCs goals is to establish the prevalence of childhood overweight in Chicago at the neighborhood or school levels. The Data Surveillance WG has worked with the Chicago Public Schools to pilot data collection for 30 of 493 elementary schools. After analysis of the pilot data, CLOCC will expand data collection to other public and parochial schools, as well as other possible settings. CLOCC is also developing a rigorous evaluation plan for its work.
CLOCC may be useful as a model for local, cooperative, overweight-prevention efforts that involve researchers, clinicians, and public health advocates in complementary and shared work. It employs an ecological approach and is guided by an understanding of critical periods in the development of overweight in childhood.
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