Abstract
This cross-sectional study assesses trends in the prevalence of obesity in children and adolescents in the US between 2011 and 2020.
Obesity among youth is a major public health concern in the US.1,2 Childhood obesity is associated with cardiometabolic comorbidities throughout life.3 This study aimed to examine changes in obesity prevalence among US youth using the most recently released nationally representative data from 2011 to 2020.
Methods
This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES), a cross-sectional survey representing the US population, for 2011 to 2012, 2013 to 2014, 2015 to 2016, and 2017 to 2020.4 The 2017 to 2020 data set consisted of data from 2017 until the COVID-19 pandemic in March 2020 that ended data collection for the 2019 to 2020 period. Combining the results of operations from 2019 to March 2020 and 2017 to 2018, the data maintained a nationally representative estimate. The response rate was 69.5% in 2011 to 2012 and declined to 46.9% in 2017 to 2020.4 Weight and height were measured using standardized techniques and equipment. Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared. The Pennington Biomedical Research Center Institutional Review Board deemed this study as non–human participant research. The study followed the STROBE reporting guideline.
Data were categorized by age group: 2 to 5 years, 6 to 11 years, 12 to 19 years, and 2 to 19 years. Obesity for children and adolescents was defined as BMI for age at or above the 95th percentile based on the Centers for Disease Control and Prevention growth chart.5 Parents reported child race and ethnicity and sex.
We estimated prevalence of obesity and 95% CIs using NHANES examination weights to account for complex sample design and adjusted for race and ethnicity in the whole sample analysis. Linear trends across all years were tested using a linear or logistic regression.6 Statistical significance was P < .05. Statistical analyses were performed using IBM SPSS Statistics for Windows, version 25.0 (IBM Corp) and SAS, version 9.4 (SAS Institute Inc).
Results
The study included 14 967 children and adolescents (mean [SD] age, 9.81 [5.07] years; 7613 [50.9%] boys and 7354 [49.1%] girls). Among youth aged 2 to 19 years, the prevalence of obesity increased from 17.7% (95% CI, 16.4%-19.0%) in 2011 to 2012 to 21.5% (95% CI, 20.3%-22.6%) in 2017 to 2020 (Table and Figure). Overall, obesity increased from 18.1% to 21.4% for boys (P for trend = .004) and 17.2% to 21.6% for girls (P for trend = .002) between the 2011 to 2012 and 2017 to 2020 periods (Figure). As shown in the Table, prevalence of obesity also increased significantly in children aged 2 to 5 years and adolescents aged 12 to 19 years but not in children aged 6 to 11 years.
Table. Prevalence of Obesity in Children and Adolescents Stratified by Age and Race and Ethnicity From 2011 to 2020a.
| Allb | Mexican American | Non-Hispanic Black | Non-Hispanic White | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of participants | Prevalence (95% CI) | P valuec | No. of participants (%) | Prevalence (95% CI) | P valuec | No. of participants (%) | Prevalence (95% CI) | P valuec | No. of participants (%) | Prevalence (95% CI) | P valuec | |
| Age 2-5 y | ||||||||||||
| 2011-2012 | 883 | 10.3 (8.20-12.5) | .046 | 288 (32.6) | 16.7 (12.2-21.1) | .39 | 276 (31.3) | 10.9 (7.10-14.6) | .60 | 164 (18.6) | 3.70 (0.00-0.81)d | .01 |
| 2013-2014 | 855 | 10.5 (8.30-12.7) | 269 (31.5) | 15.6 (11.0-20.2) | 212 (24.8) | 9.34 (5.10-13.7) | 231 (27.0) | 7.40 (3.60-11.1) | ||||
| 2015-2016 | 827 | 13.9 (11.7-16.1) | 247 (29.9) | 18.2 (13.4-23.0) | 209 (25.3) | 13.4 (9.10-17.7) | 242 (29.3) | 12.4 (8.80-16.0) | ||||
| 2017-2020 | 1154 | 12.9 (11.1-14.8) | 246 (21.3) | 21.1 (16.3-25.9) | 321 (27.8) | 12.1 (8.70-15.6) | 390 (33.8) | 10.8 (7.90-13.6) | ||||
| Age 6-11 y | ||||||||||||
| 2011-2012 | 1268 | 20.5 (18.3-22.7) | .09 | 397 (31.3) | 25.9 (21.6-30.3) | .41 | 365 (28.8) | 22.7 (18.5-27.0) | .10 | 300 (23.7) | 17.0 (12.8-21.2) | .27 |
| 2013-2014 | 1307 | 19.1 (16.9-21.3) | 411 (31.4) | 24.6 (20.3-28.9) | 358 (27.4) | 19.0 (14.7-23.3) | 343 (26.2) | 15.5 (11.5-19.4) | ||||
| 2015-2016 | 1269 | 20.4 (18.1-22.6) | 461 (36.3) | 27.5 (23.5-31.6) | 271 (21.4) | 20.3 (15.3-25.3) | 350 (27.6) | 14.0 (10.1-17.9) | ||||
| 2017-2020 | 1770 | 22.8 (20.9-24.6) | 459 (25.9) | 29.4 (25.3-33.5) | 489 (27.6) | 25.8 (22.1-29.5) | 504 (28.5) | 18.8 (15.6-22.1) | ||||
| Age 12-19 y | ||||||||||||
| 2011-2012 | 1204 | 20.1 (17.7-22.4) | .001 | 350 (29.1) | 21.4 (16.9-26.0) | .08 | 367 (30.5) | 22.9 (18.4-27.4) | .10 | 264 (21.9) | 19.7 (14.9-24.5) | .06 |
| 2013-2014 | 1361 | 20.9 (18.7-23.1) | 463 (34.0) | 23.5 (19.6-27.5) | 332 (24.4) | 23.5 (18.8-28.2) | 345 (25.3) | 20.3 (16.1-24.5) | ||||
| 2015-2016 | 1244 | 21.7 (19.4-24.0) | 418 (33.6) | 28.0 (23.8-32.2) | 287 (23.1) | 25.8 (20.7-30.8) | 333 (26.8) | 15.6 (11.3-19.9) | ||||
| 2017-2020 | 1825 | 25.6 (23.7-27.5) | 438 (24.0) | 27.9 (23.8-31.9) | 460 (25.2) | 29.8 (25.8-33.8) | 577 (31.6) | 23.1 (19.8-26.3) | ||||
| Age 2-19 y | ||||||||||||
| 2011-2012 | 3355 | 17.7 (16.4-19.0) | <.001 | 1035 (30.8) | 21.8 (19.2-24.4)e | .006 | 1008 (30.0) | 19.5 (17.0-22.0)f | .01 | 728 (21.7) | 15.0 (12.3-17.6)e,f | .03 |
| 2013-2014 | 3523 | 17.7 (16.4-19.0) | 1143 (32.4) | 22.0 (19.6-24.5)e,g | 902 (25.6) | 18.4 (15.8-21.1)g | 919 (26.1) | 15.2 (12.9-17.6)e | ||||
| 2015-2016 | 3340 | 19.3 (17.9-20.6) | 1126 (33.7) | 25.7 (23.2-28.2)e,g | 767 (23.0) | 20.5 (17.6-23.3)f,g | 925 (27.7) | 14.2 (11.8-16.5)e,f | ||||
| 2017-2020 | 4749 | 21.5 (20.3-22.6) | 1143 (24.1) | 27.0 (24.6-29.5)e | 1270 (26.7) | 23.8 (21.5-26.0)f | 1471 (31.0) | 18.4 (16.5-20.2)e,f | ||||
Data are from the National Health and Nutrition Examination Survey; all estimates except samples sizes were weighted. The values in the No. of participants columns for each race and ethnicity do not sum to the values in the No. of participants column under All because Asian individuals and those of more than 1 race and ethnicity were not included as subgroups because of the low sample sizes.
Includes all self-reported race and ethnicity groups. All estimates were adjusted for race and ethnicity.
The linear trends were conducted using 2-year cycles except for 2017 to 2020.
The number of individuals with obesity was fewer than 10.
Values for the prevalence difference of obesity between Mexican American and non-Hispanic White individuals were significant at P < .05.
Values for the prevalence difference of obesity between non-Hispanic Black and non-Hispanic White individuals were significant at P < .05.
Values for the prevalence difference of obesity between Mexican American and non-Hispanic Black individuals were significant at P < .05.
Figure. Prevalence of Obesity in US Youth Aged 2 to 19 Years Stratified by Sex From 2011 to 2020.
All estimates were adjusted for race and ethnicity.
Among all participants, there were increased trends for obesity from the 2011 to 2012 to the 2017 to 2020 periods for Mexican American (21.8% to 27.0%; P for trend = .006), non-Hispanic Black (19.5% to 23.8%; P for trend = .01), and non-Hispanic White (15.0% to 18.4%; P for trend = .03) individuals. However, no significant trends for obesity existed for groups aged 2 to 5, 6 to 11, or 12 to 19 years for each race and ethnicity.
Discussion
Between 2011 to 2012 and 2017 to 2020, obesity increased for children aged 2 to 5 years, adolescents aged 12 to 19 years, and children aged 2 to 19 years of all races and ethnicities. A limitation of the study is the decreased response rates for NHANES. Moreover, there was a small sample size and low cases of obesity when we stratified data among different ages and races and ethnicities. Because of the significant increase in obesity, there is an urgent need for identification of antecedents and correlates of adiposity and cardiometabolic risk for early obesity prevention.
References
- 1.Hales CM, Fryar CD, Carroll MD, Freedman DS, Ogden CL. Trends in obesity and severe obesity prevalence in US youth and adults by sex and age, 2007-2008 to 2015-2016. JAMA. 2018;319(16):1723-1725. doi: 10.1001/jama.2018.3060 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Fryar CD, Carroll MD, Afful J. Prevalence of overweight, obesity, and severe obesity among children and adolescents aged 2–19 years: United States, 1963–1965 through 2017–2018. Centers for Disease Control and Prevention National Center for Health Statistics. Updated January 29, 2021. Accessed April 6, 2022. https://www.cdc.gov/nchs/data/hestat/obesity-child-17-18/obesity-child.htm
- 3.Weihrauch-Blüher S, Schwarz P, Klusmann JH. Childhood obesity: increased risk for cardiometabolic disease and cancer in adulthood. Metabolism. 2019;92:147-152. doi: 10.1016/j.metabol.2018.12.001 [DOI] [PubMed] [Google Scholar]
- 4.National Health and Nutrition Examination Survey. Centers for Disease Control and Prevention National Center for Health Statistics . Updated May 6, 2022. Accessed May 6, 2022. https://www.cdc.gov/nchs/nhanes/index.htm.
- 5.Kuczmarski RJ, Ogden CL, Guo SS, et al. 2000 CDC growth charts for the United States: methods and development. Vital Health Stat 11. 2002;2002(246):1-190. [PubMed] [Google Scholar]
- 6.Ingram DD, Malec DJ, Makuc DM, et al. National Center for Health Statistics guidelines for analysis of trends. Vital Health Stat 2. 2018;179:1-71. [PubMed] [Google Scholar]