IMPORTANCE More than one-third of adults and 17% of youth in the United States are obese, although the prevalence remained stable between 2003–2004 and 2009–2010. OBJECTIVE To provide the most recent national estimates of childhood obesity, analyze trends in childhood obesity between 2003 and 2012, and provide detailed obesity trend analyses among adults. DESIGN, SETTING, AND PARTICIPANTS Weight and height or recumbent length were measured in 9120 participants in the 2011–2012 nationally representative National Health and Nutrition Examination Survey. MAIN OUTCOMES AND MEASURES In infants and toddlers from birth to 2 years, high weight for recumbent length was defined as weight for length at or above the 95th percentile of the sex-specific Centers for Disease Control and Prevention (CDC) growth charts. In children and adolescents aged 2 to 19 years, obesity was defined as a body mass index (BMI) at or above the 95th percentile of the sex-specific CDC BMI-for-age growth charts. In adults, obesity was defined as a BMI greater than or equal to 30. Analyses of trends in high weight for recumbent length or obesity prevalence were conducted overall and separately by age across 5 periods (2003–2004, 2005–2006, 2007–2008, 2009–2010, and 2011–2012). RESULTS In 2011–2012, 8.1% (95% CI, 5.8%–11.1%) of infants and toddlers had high weight for recumbent length, and 16.9% (95% CI, 14.9%–19.2%) of 2- to 19-year-olds and 34.9% (95% CI, 32.0%–37.9%) of adults (age-adjusted) aged 20 years or older were obese. Overall, there was no significant change from 2003–2004 through 2011–2012 in high weight for recumbent length among infants and toddlers, obesity in 2- to 19-year-olds, or obesity in adults. Tests for an interaction between survey period and age found an interaction in children (P = .03) and women (P = .02). There was a significant decrease in obesity among 2- to 5-year-old children (from 13.9% to 8.4%; P = .03) and a significant increase in obesity among women aged 60 years and older (from 31.5% to 38.1%; P = .006). CONCLUSIONS AND RELEVANCE Overall, there have been no significant changes in obesity prevalence in youth or adults between 2003–2004 and 2011–2012. Obesity prevalence remains high and thus it is important to continue surveillance.

VERALL TRENDS IN OBESITYin the adult population of the United States can be tracked using national survey data that include measured heights and weights. Based on national survey data, the population prevalence of obesity, defined as a body mass index (BMI) of 30 or greater (calculated as weight in kilograms divided by height in meters squared), showed little change in the

Context The prevalence of childhood obesity increased in the 1980s and 1990s but there were no significant changes in prevalence between 1999-2000 and 2007-2008 in the United States. Objectives To present the most recent estimates of obesity prevalence in US children and adolescents for 2009-2010 and to investigate trends in obesity prevalence and body mass index (BMI) among children and adolescents between 1999-2000 and 2009-2010. Design, Setting, and Participants Cross-sectional analyses of a representative sample (N=4111) of the US child and adolescent population (birth through 19 years of age) with measured heights and weights from the National Health and Nutrition Examination Survey 2009-2010. Main Outcome Measures Prevalence of high weight-for-recumbent length (Ն95th percentile on the growth charts) among infants and toddlers from birth to 2 years of age and obesity (BMI Ն95th percentile of the BMI-forage growth charts) among children and adolescents aged 2 through 19 years. Analyses of trends in obesity by sex and race/ethnicity, and analyses of trends in BMI within sex-specific age groups for 6

Importance Estimates of the relative mortality risks associated with normal weight, overweight, and obesity may help to inform decision making in the clinical setting. Objective To perform a systematic review of reported hazard ratios (HRs) of all-cause mortality for overweight and obesity relative to normal weight in the general population. Data Sources PubMed and EMBASE electronic databases were searched through September 30, 2012, without language restrictions. Study Selection Articles that reported HRs for all-cause mortality using standard body mass index (BMI) categories from prospective studies of general populations of adults were selected by consensus among multiple reviewers. Studies were excluded that used nonstandard categories or that were limited to adolescents or to those with specific medical conditions or to those undergoing specific procedures. PubMed searches yielded 7034 articles, of which 141 (2.0%) were eligible. An EMBASE search yielded 2 additional articles. After eliminating overlap, 97 studies were retained for analysis, providing a combined sample size of more than 2.88 million individuals and more than 270 000 deaths. Data Extraction Data were extracted by 1 reviewer and then reviewed by 3 independent reviewers. We selected the most complex model available for the full sample and used a variety of sensitivity analyses to address issues of possible overadjustment (adjusted for factors in causal pathway) or underadjustment (not adjusted for at least age, sex, and smoking). Results Random-effects summary all-cause mortality HRs for overweight (BMI of 25–<30), obesity (BMI of ≥30), grade 1 obesity (BMI of 30–<35), and grades 2 and 3 obesity (BMI of ≥35) were calculated relative to normal weight (BMI of 18.5–<25). The summary HRs were 0.94 (95% CI, 0.91–0.96) for overweight, 1.18 (95% CI, 1.12–1.25) for obesity (all grades combined), 0.95 (95% CI, 0.88–1.01) for grade 1 obesity, and 1.29 (95% CI, 1.18–1.41) for grades 2 and 3 obesity. These findings persisted when limited to studies with measured weight and height that were considered to be adequately adjusted. The HRs tended to be higher when weight and height were self-reported rather than measured. Conclusions and Relevance Relative to normal weight, both obesity (all grades) and grades 2 and 3 obesity were associated with significantly higher all-cause mortality. Grade 1 obesity overall was not associated with higher mortality, and overweight was associated with significantly lower all-cause mortality. The use of predefined standard BMI groupings can facilitate between-study comparisons.