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A Methods F ormulation of policy recommendations calls for careful consideration of the evidence associated with one course of action or another. The Committee on Obesity Prevention Policies for Young Children carefully con- sidered both direct and indirect evidence regarding the likely impact of a given policy on reducing childhood obesity. We also considered evidence pertaining to the potential for unintended adverse effects. Although we did not conduct a comprehensive, systematic evidence review on each important policy-related question, our collective expertise and consideration of the most pertinent studies yielded recommendations that are consistent with the evidence base. In areas in which the committee identified a need for additional information, outside experts were called upon at a public workshop held on June 2, 2010, in Washington, DC, titled “Emerging Issues, Programs, and Policy Needs in Early Childhood Obesity Prevention.” The ideal evidence to support policy recommendations would be a series of experimental studies testing the impact of various policies on childhood obesity in representative settings. Given the rarity of such studies and the urgent need to address the enormous health impacts of obesity, however, we could not restrict ourselves to making recommendations in the few areas in which such firm evidence exists. Observational studies are easier to conduct and thus far more common, and we gave strong studies of this type serious consideration. Although we recognize that conclusions regarding causality that can be drawn from such studies are less firm, we believe that evidence from 149

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repeated, well-conducted observational studies can provide sufficient support for policy recommendations. We also were receptive to evidence that a policy would be likely to affect a determinant of childhood obesity even if not studied for its direct influence on obesity. That is, we recommend policy changes expected to increase physical activity or promote more healthy eating in children because such intermediate outcomes are themselves associated with prevention of childhood obesity. Our recommendations are predicated on the belief, supported by evidence, that a change in the target of a policy will produce the desired change in obe- sity or its behavioral risk factors (e.g., a policy resulting in reduced consumption of soft drinks would contribute to obesity prevention). This belief reflects an informed judgment that considers the quality of the studies and the results they generate. Another important consideration is the possibility that a policy intended to reduce childhood obesity could have unintended adverse consequences. For example, policies to promote physical activity among children must take into account the potential for increased risk of injury. Because many important devel- opmental processes occur during gestation and early childhood, it is essential to be as certain as possible that none of the recommended policy changes could have irreversible adverse effects during these critical periods. Lacking direct evidence in most cases, we relied on more subjective consideration of the plausibility of such consequences. We also considered ways to mitigate potential adverse conse- quences, such as environmental design to reduce playground injuries among young children. In the report we note the current state of the scientific evidence pertinent to the recommended policies, including both uncertainties and areas in which research is needed. Ultimately, our recommendations take full account of the sci- entific data but also reflect our collective best judgment. We have attempted to be consistent in our approach to combining scientific evidence and expert judgment, holding policy options to the same standards. The urgency of addressing obesity in young children requires taking action rather than waiting for more conclusive research—applying the “best available” rather than the “best possible” evidence. Research in this context includes studies of more effective means of implement- ing or enforcing policy changes to reduce childhood obesity. Some of our policy recommendations (or our unwillingness to make recommendations) fall on the cusp of the scientific evidence, barely or almost sufficient, and those are issues for which more research could well tip the balance in one direction or another. Early Childhood Obesity Prevention Policies 150

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As new policies to prevent childhood obesity are implemented, it is impor- tant that those policies be evaluated to (1) support further action where success can be demonstrated; (2) ensure that policies that fail to act in the intended man- ner are reconsidered; and particularly (3) assess any unintended adverse conse- quences. As new evidence emerges, it will be important to reexamine our policy recommendations and make any necessary revisions. Thus it is essential to act aggressively based on what is known now while putting in place the necessary processes for research and policy evaluation to ensure that action can be taken even more wisely and effectively in the future. 151 Appendix A

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