This targeted systematic review was undertaken to assist the United States Preventive Services Task Force (USPSTF) in updating its previous recommendation on screening and interventions for overweight in children and adolescents. Based on our previous systematic review in 2005, the USPSTF found insufficient evidence to recommend screening for overweight, due to uncertainties about the effectiveness of behavior counseling or other interventions with overweight children and adolescents that could be conducted in primary care settings or to which primary care clinicians can make referrals. Given recent work on another systematic review, Effectiveness of Weight Management Programs in Children and Adolescents, the USPSTF determined to focus its update on what was considered the critical evidence gap at the time of our last systematic review to allow an efficient and timely updating of their recommendation. Thus, for this targeted updated systematic review, we examine previous and newly available evidence on behavioral and pharmacological weight management interventions for overweight and/or obese children and adolescents (defined as those between 2 and 18 years of age that meet criteria for increased body mass index [BMI] appropriate to their age and sex) that are relevant to primary care practice. Attention to these differences in terminology is key, as children and adolescents defined as "overweight" in the 2005 report would now be defined as "obese". And, while the current review is intended to fill the critical evidence gap about intervention effectiveness identified during the 2005 review, our previous review also found that there was insufficient evidence to ascertain the magnitude of the potential harms of screening or intervention. In this targeted update, the USPSTF focused our attention on updating both the benefits and potential harms of primary care feasible interventions, but did not choose to update the evidence on screening benefits or harms. Evidence on the harms as well as benefits of BMI screening programs, along with good data on the diagnostic accuracy of BMI as a measure of obesity in children, still appear to be lacking, resulting in arguments against the use of BMI screening of individuals in schools or in other screening programs that go beyond its use as a tool by clinicians for monitoring growth and development. The previous review also found fair evidence that obese adolescents and children (i.e., those at or above the 95th BMI percentile for age and sex) aged 8 years and older are at increased risk for becoming obese adults. Evidence on the benefits and harms of screening and on the risk of pediatric obesity persisting into adulthood will not be updated in the current review. Additionally, in keeping with the USPSTF focus on primary and secondary clinical preventive services, surgical treatment of obesity was considered out of scope for this updated review, since surgical treatment is only considered for extremely obese young people, particularly those who are experiencing negative health effects as a result of their obesity necessitating treatment. We therefore focus on behavioral and pharmacological interventions, both of which may be appropriate for less obese or overweight children who would be identified and treated in or in coordination with primary care. While prevention is a critical component of an overall public health strategy to address the dramatic increase in childhood and adolescent overweight in the United States and elsewhere, recent reviews indicate little empirical evidence of effective interventions for preventing development of overweight in clinical settings and are not included in this report. Guidance on obesity prevention thereby generally focuses on pragmatic advice for clinicians or on settings with evidence, as in schools and, to a lesser extent, community settings.