Margaret D. Carroll

CONTEXT: The prevalence of overweight in children and adolescents and obesity in adults in the United States has increased over several decades. OBJECTIVE: To provide current estimates of the prevalence and trends of overweight in children and adolescents and obesity in adults. DESIGN, SETTING, AND PARTICIPANTS: Analysis of height and weight measurements from 3958 children and adolescents aged 2 to 19 years and 4431 adults aged 20 years or older obtained in 2003-2004 as part of the National Health and Nutrition Examination Survey (NHANES), a nationally representative sample of the US population. Data from the NHANES obtained in 1999-2000 and in 2001-2002 were compared with data from 2003-2004. MAIN OUTCOME MEASURES: Estimates of the prevalence of overweight in children and adolescents and obesity in adults. Overweight among children and adolescents was defined as at or above the 95th percentile of the sex-specific body mass index (BMI) for age growth charts. Obesity among adults was defined as a BMI of 30 or higher; extreme obesity was defined as a BMI of 40 or higher. RESULTS: In 2003-2004, 17.1% of US children and adolescents were overweight and 32.2% of adults were obese. Tests for trend were significant for male and female children and adolescents, indicating an increase in the prevalence of overweight in female children and adolescents from 13.8% in 1999-2000 to 16.0% in 2003-2004 and an increase in the prevalence of overweight in male children and adolescents from 14.0% to 18.2%. Among men, the prevalence of obesity increased significantly between 1999-2000 (27.5%) and 2003-2004 (31.1%). Among women, no significant increase in obesity was observed between 1999-2000 (33.4%) and 2003-2004 (33.2%). The prevalence of extreme obesity (body mass index > or =40) in 2003-2004 was 2.8% in men and 6.9% in women. In 2003-2004, significant differences in obesity prevalence remained by race/ethnicity and by age. Approximately 30% of non-Hispanic white adults were obese as were 45.0% of non-Hispanic black adults and 36.8% of Mexican Americans. Among adults aged 20 to 39 years, 28.5% were obese while 36.8% of adults aged 40 to 59 years and 31.0% of those aged 60 years or older were obese in 2003-2004. CONCLUSIONS: The prevalence of overweight among children and adolescents and obesity among men increased significantly during the 6-year period from 1999 to 2004; among women, no overall increases in the prevalence of obesity were observed. These estimates were based on a 6-year period and suggest that the increases in body weight are continuing in men and in children and adolescents while they may be leveling off in women.

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.

CONTEXT: Between 1980 and 1999, the prevalence of adult obesity (body mass index [BMI] ≥30) increased in the United States and the distribution of BMI changed. More recent data suggested a slowing or leveling off of these trends. OBJECTIVE: To estimate the prevalence of adult obesity from the 2009-2010 National Health and Nutrition Examination Survey (NHANES) and compare adult obesity and the distribution of BMI with data from 1999-2008. DESIGN, SETTING, AND PARTICIPANTS: NHANES includes measured heights and weights for 5926 adult men and women from a nationally representative sample of the civilian noninstitutionalized US population in 2009-2010 and for 22,847 men and women in 1999-2008. MAIN OUTCOME MEASURES: The prevalence of obesity and mean BMI. RESULTS: In 2009-2010 the age-adjusted mean BMI was 28.7 (95% CI, 28.3-29.1) for men and also 28.7 (95% CI, 28.4-29.0) for women. Median BMI was 27.8 (interquartile range [IQR], 24.7-31.7) for men and 27.3 (IQR, 23.3-32.7) for women. The age-adjusted prevalence of obesity was 35.5% (95% CI, 31.9%-39.2%) among adult men and 35.8% (95% CI, 34.0%-37.7%) among adult women. Over the 12-year period from 1999 through 2010, obesity showed no significant increase among women overall (age- and race-adjusted annual change in odds ratio [AOR], 1.01; 95% CI, 1.00-1.03; P = .07), but increases were statistically significant for non-Hispanic black women (P = .04) and Mexican American women (P = .046). For men, there was a significant linear trend (AOR, 1.04; 95% CI, 1.02-1.06; P < .001) over the 12-year period. For both men and women, the most recent 2 years (2009-2010) did not differ significantly (P = .08 for men and P = .24 for women) from the previous 6 years (2003-2008). Trends in BMI were similar to obesity trends. CONCLUSION: In 2009-2010, the prevalence of obesity was 35.5% among adult men and 35.8% among adult women, with no significant change compared with 2003-2008.

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 (≥95th percentile on the growth charts) among infants and toddlers from birth to 2 years of age and obesity (BMI ≥95th percentile of the BMI-for-age 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 survey periods (1999-2000, 2001-2002, 2003-2004, 2005-2006, 2007-2008, and 2009-2010) over 12 years. RESULTS: In 2009-2010, 9.7% (95% CI, 7.6%-12.3%) of infants and toddlers had a high weight-for-recumbent length and 16.9% (95% CI, 15.4%-18.4%) of children and adolescents from 2 through 19 years of age were obese. There was no difference in obesity prevalence among males (P = .62) or females (P = .65) between 2007-2008 and 2009-2010. However, trend analyses over a 12-year period indicated a significant increase in obesity prevalence between 1999-2000 and 2009-2010 in males aged 2 through 19 years (odds ratio, 1.05; 95% CI, 1.01-1.10) but not in females (odds ratio, 1.02; 95% CI, 0.98-1.07) per 2-year survey cycle. There was a significant increase in BMI among adolescent males aged 12 through 19 years (P = .04) but not among any other age group or among females. CONCLUSION: In 2009-2010, the prevalence of obesity in children and adolescents was 16.9%; this was not changed compared with 2007-2008.

Obesity is associated with serious health risks. Monitoring obesity prevalence is relevant for public health programs that focus on reducing or preventing obesity. Between 2003–2004 and 2013–2014, there were no significant changes in childhood obesity prevalence, but adults showed an increasing trend. This report provides the most recent national estimates from 2015–2016 on obesity prevalence by sex, age, and race and Hispanic origin, and overall estimates from 1999–2000 through 2015–2016.