espite recent data suggesting that the rate of increase of obesity among children and adolescents has slowed and overall prevalence has possibly begun to plateau, 1,2 a worrisome trend has emerged in the form of severe pediatric obesity. As the fastest-growing subcategory of obesity in children and adolescents, 1,3,4 severe obesity afflicts between 4% and 6% of all youth in the United States 3-7 and has both immediate and long-term health consequences. Recent data further Abstract-Severe obesity afflicts between 4% and 6% of all youth in the United States, and the prevalence is increasing.Despite the serious immediate and long-term cardiovascular, metabolic, and other health consequences of severe pediatric obesity, current treatments are limited in effectiveness and lack widespread availability. Lifestyle modification/behaviorbased treatment interventions in youth with severe obesity have demonstrated modest improvement in body mass index status, but participants have generally remained severely obese and often regained weight after the conclusion of the treatment programs. The role of medical management is minimal, because only 1 medication is currently approved for the treatment of obesity in adolescents. Bariatric surgery has generally been effective in reducing body mass index and improving cardiovascular and metabolic risk factors; however, reports of long-term outcomes are few, many youth with severe obesity do not qualify for surgery, and access is limited by lack of insurance coverage. To begin to address these challenges, the purposes of this scientific statement are to (1) provide justification for and recommend a standardized definition of severe obesity in children and adolescents; (2) raise awareness of this serious and growing problem by summarizing the current literature in this area in terms of the epidemiology and trends, associated health risks (immediate and long-term), and challenges and shortcomings of currently available treatment options; and (3) highlight areas in need of future research. Innovative behavior-based treatment, minimally invasive procedures, and medications currently under development all need to be evaluated for their efficacy and safety in this group of patients with high medical and psychosocial risks. (Circulation. 2013;128:1689-1712.)

T he prevalence of obesity in the United States and the world has risen to epidemic/pandemic proportions. This increase has occurred despite great efforts by healthcare providers and consumers alike to improve the health-related behaviors of the population and a tremendous push from the scientific community to better understand the pathophysiology of obesity. This epidemic is all the more concerning given the clear association between excess adiposity and adverse health consequences such as cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). The risks associated with overweight/obesity are primarily related to the deposition of adipose tissue, which leads to excess adiposity or body fatness. Furthermore, weight loss, specifically loss of body fat, is associated with improvement in obesity-related comorbidities. Before weight loss interventions can be recommended, however, patients must be assessed for their adiposity-related risk. Unfortunately, healthcare providers and systems have not done a good job of assessing for excess adiposity even in its simplest form, such as measuring body mass index (BMI). It is for these reasons that we must emphasize the importance of assessing adiposity in clinical practices. Although it can be argued that the entire population should be targeted as an important public health issue with a goal of prevention of weight gain and obesity, there are currently so many "at risk" individuals that simple strategies to identify and treat those individuals are necessary. We must identify those individuals at highest risk of comorbidities in order to identify those who might benefit the most from aggressive weight management.This scientific statement will first briefly review the epidemiology of obesity and its related comorbidities, supporting the need for improved assessment of adiposity in daily clinical practice. This will be followed by a discussion of some of the challenges and issues associated with assessing adiposity and then by a review of the methods available for assessing adiposity in adults. Finally, practical recommendations for the clinician in practice will be given with a goal of identifying more at-risk overweight/obese individuals.

Until recently, the majority of cases of diabetes mellitus among children and adolescents were immune-mediated type 1a diabetes. Obesity has led to a dramatic increase in the incidence of type 2 diabetes (T2DM) among children and adolescents over the past 2 decades. Obesity is strongly associated with insulin resistance, which, when coupled with relative insulin deficiency, leads to the development of overt T2DM. Children and adolescents with T2DM may experience the microvascular and macrovascular complications of this disease at younger ages than individuals who develop diabetes in adulthood, including atherosclerotic cardiovascular disease, stroke, myocardial infarction, and sudden death; renal insufficiency and chronic renal failure; limb-threatening neuropathy and vasculopathy; and retinopathy leading to blindness. Health care professionals are advised to perform the appropriate screening in children at risk for T2DM, diagnose the condition as early as possible, and provide rigorous management of the disease.

This scientific statement is about sedentary behavior and its relationship to obesity and other cardiometabolic outcomes in youth. A deleterious effect of sedentary behavior on cardiometabolic health is most notable for screen-based behaviors and adiposity; however, this relation is less apparent for other cardiometabolic outcomes or when sedentary time is measured with objective movement counters or position monitors. Increasing trends of screen time are concerning; the portability of screen-based devices and abundant access to unlimited programming and online content may be leading to new patterns of consumption that are exposing youth to multiple pathways harmful to cardiometabolic health. This American Heart Association scientific statement provides an updated perspective on sedentary behaviors specific to modern youth and their impact on cardiometabolic health and obesity. As we reflect on implications for practice, research, and policy, what emerges is the importance of understanding the context in which sedentary behaviors occur. There is also a need to capture the nature of sedentary behavior more accurately, both quantitatively and qualitatively, especially with respect to recreational screen-based devices. Further evidence is required to better inform public health interventions and to establish detailed quantitative guidelines on specific sedentary behaviors in youth. In the meantime, we suggest that televisions and other recreational screen-based devices be removed from bedrooms and absent during meal times. Daily device-free social interactions and outdoor play should be encouraged. In addition, parents/guardians should be supported to devise and enforce appropriate screen time regulations and to model healthy screen-based behaviors.

Meta-analyses are becoming increasingly popular, especially in the fields of cardiovascular disease prevention and treatment. They are often considered to be a reliable source of evidence for making healthcare decisions. Unfortunately, problems among meta-analyses such as the misapplication and misinterpretation of statistical methods and tests are long-standing and widespread. The purposes of this statement are to review key steps in the development of a metaanalysis and to provide recommendations that will be useful for carrying out meta-analyses and for readers and journal editors, who must interpret the findings and gauge methodological quality. To make the statement practical and accessible, detailed descriptions of statistical methods have been omitted. Based on a survey of cardiovascular metaanalyses, published literature on methodology, expert consultation, and consensus among the writing group, key recommendations are provided. Recommendations reinforce several current practices, including protocol registration; comprehensive search strategies; methods for data extraction and abstraction; methods for identifying, measuring, and dealing with heterogeneity; and statistical methods for pooling results. Other practices should be discontinued, including the use of levels of evidence and evidence hierarchies to gauge the value and impact of different study designs (including meta-analyses) and the use of structured tools to assess the quality of studies to be included in a metaanalysis. We also recommend choosing a pooling model for conventional meta-analyses (fixed effect or random effects) on the basis of clinical and methodological similarities among studies to be included, rather than the results of a test for statistical heterogeneity. CLINICAL STATEMENTS AND GUIDELINES D espite the increasing popularity of meta-analyses and systematic reviews in general, problems with methodology are widespread and frequently undermine the credibility of the results. New guidance is needed for both researchers who carry out meta-analyses and systematic reviews in general and the consumers who read them and rely on the results. The term meta-analysis was coined in 1976 by the American statistician Gene Glass, who wrote, "I use it to refer to the statistical analysis of a large collection of results from individual studies for the purpose of integrating findings. It connotes a rigorous alternative to the casual, narrative discussions of research studies which typify our attempts to make sense of the rapidly expanding literature."1 Meta-analyses are a subcategory of the broader category of studies known as systematic reviews.Qualitative systematic reviews include explicit and detailed methods for identification, selection, and grading the quality of individual studies and overall evidence but do not pool results across studies. Meta-analysis is synonymous with the term quantitative systematic review and by definition includes pooling of results across studies. The emphasis in this statement is on metaanalysis bec...

National guidelines for the diagnosis and management of hypertension in children have been available for nearly 40 years. Unfortunately, knowledge and recognition of the problem by clinicians remain poor. Prevalence estimates are highly variable because of differing standards, populations, and blood pressure (BP) measurement techniques. Estimates in the United States range from 0.3% to 4.5%. Risk factors for primary hypertension include overweight and obesity, male sex, older age, high sodium intake, and African American or Latino ancestry. Data relating hypertension in childhood to later cardiovascular events is currently lacking. It is known that BP in childhood is highly predictive of BP in adulthood. Compelling data about target organ damage is available, including the association of hypertension with left ventricular hypertrophy, carotid-intima media thickness, and microalbuminuria. Guidelines from both the United States and Europe include detailed recommendations for diagnosis and management. Diagnostic standards are based on clinic readings, ambulatory BP monitoring is useful in confirming diagnosis of hypertension and identifying white-coat hypertension, masked hypertension, and secondary hypertension, as well as monitoring response to therapy. Research priorities include the need for reliable prevalence estimates based on diverse populations and data about the long-term impact of childhood hypertension on cardiovascular morbidity and mortality. Priorities to improve clinical practice include more education among clinicians about diagnosis and management, clinical decision support to aid in diagnosis, and routine use of ambulatory BP monitoring to aid in diagnosis and to monitor response to treatment.

“Eat a variety of foods,” or dietary diversity, is a widely accepted recommendation to promote a healthy, nutritionally adequate diet and to reduce the risk of major chronic diseases. However, recent evidence from observational studies suggests that greater dietary diversity is associated with suboptimal eating patterns, that is, higher intakes of processed foods, refined grains, and sugar-sweetened beverages and lower intakes of minimally processed foods, such as fish, fruits, and vegetables, and may be associated with weight gain and obesity in adult populations. This American Heart Association science advisory summarizes definitions for dietary diversity and reviews current evidence on its relationship with obesity outcomes, eating behavior, and food-based diet quality measures. Current data do not support greater dietary diversity as an effective strategy to promote healthy eating patterns and healthy body weight. Given the current state of the science on dietary diversity and the insufficient data to inform recommendations on specific aspects of dietary diversity that may be beneficial or detrimental to healthy weight, it is appropriate to promote a healthy eating pattern that emphasizes adequate intake of plant foods, protein sources, low-fat dairy products, vegetable oils, and nuts and limits consumption of sweets, sugar-sweetened beverages, and red meats.

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