NCHS Data Brief ■ No. 211 ■ August 2015

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention

National Center for Health Statistics

About one-quarter of Canadian adults and more than one-third of adults 

in the United States are obese (1). Obese children are at risk of becoming 

obese adults (2) and can experience immediate health consequences such as 

psychosocial stress, elevated blood pressure and cholesterol, and abnormal 

glucose tolerance (3). Monitoring trends in childhood obesity is important in 

order to assess interventions aimed at reducing the burden of obesity. 

Keywords: Canadian Health Measures Survey • body mass index • 

international comparison • National Health and Nutrition Examination Survey

Have changes in obesity prevalence in the last 30 years been 

similar in Canada and the United States? 

During the late 1970s, there was no difference between Canada and the United 

States in the prevalence of childhood obesity (approximately 5% in both 

Key findings 

● In the late 1970s, the 

prevalence of childhood obesity 

was the same in Canada and the 

United States, but recently the 

prevalence is 4.5 percentage 

points higher in the United 

States than in Canada.

● No change has been seen 

over the last decade in the 

prevalence of obesity among 

children and adolescents in 

Canada or the United States.

● The prevalence of obesity 

among children and adolescents 

aged 3–19 in Canada was lower 

(13.0%) than in the United 

States (17.5%) in recent years.

● There was no difference 

between Canada and the United 

States in the prevalence of 

obesity among children aged 

3–6 years.

● In the non-Hispanic white 

population, the prevalence 

of obesity among girls was 

lower in Canada than in the 

United States, but there was 

no difference between the two 

countries among boys.

Prevalence of Obesity Among Children and Adolescents in 

the United States and Canada

Margaret D. Carroll, M.S.P.H.; Tanya Navaneelan, M.Sc.; Shirley Bryan, Ph.D.;

and Cynthia L. Ogden, Ph.D.

0

10

20

30

1

2009–2012

United States

1

2001–2004

United States

1976–1980

United States

Percent

United States

Canada

Figure 1. Trends in childhood obesity among children and adolescents aged 3–19 in Canada and 

the United States

1

Statistically significant difference compared with Canada, p < 0.001.

NOTE: Pregnant girls are excluded.

SOURCES: CDC/NCHS, National Health and Nutrition Examination Surveys, 1976–1980, 2001–2004, and 2009–2012; Canada 

Health, 1978–1979; Canadian Community Health Survey—Nutrition 2004; and Canadian Health Measures Survey, 2009–2013.

17.5

16.6

5.6

13.0 12.4

5.0

1978–1979

Canada

2004

Canada

2009–2013

Canada
NCHS Data Brief ■ No. 211 ■ August 2015

■  2  ■

countries) (Figure 1). An increasing trend in childhood obesity has been seen in both countries, 

but the increase was greater in the United States. Beginning in the early part of the 21st century, 

the prevalence of childhood obesity was approximately 4 percentage points lower in Canada 

(12.4% in 2004; 13.0% in 2009–2013) than in the United States (16.6% in 2001–2004; 17.5% in 

2009–2012), although there was no significant change between the two most recent time periods 

in either country.

Were differences by age seen in the prevalence of childhood obesity 

between Canada and the United States?

Among children aged 7–12, the prevalence of obesity was more than 7 percentage points 

lower in Canada compared with the United States (11.8% in Canada and 19.2% in the United 

States) (Figure 2). For children aged 3–6 and adolescents aged 13–19, there were no significant 

differences in the prevalence of obesity in Canada and United States. For adolescents aged 13–19, 

the sample size may not have been large enough to detect a difference.

0

5

10

15

20

25

30

3–19 3–6 7–12 13–19

Percent

1

17.5

13.0 12.3 10.8 11.8

19.1

15.0

1

19.2

Figure 2. Childhood obesity among children and adolescents aged 3–19, by age: Canada, 2009–2013, and United States, 

2009–2012

1

Statistically significant difference compared with Canada, p < 0.001.

NOTE: Pregnant girls are excluded.

SOURCES: CDC/NCHS, National Health and Nutrition Examination Survey, 2009–2012, and Canadian Health Measures Survey, 2009–2013.

Canada United States

Age group (years)
NCHS Data Brief ■ No. 211 ■ August 2015

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Were differences by sex and age seen in the prevalence of childhood 

obesity between Canada and the United States? 

Overall, among children and adolescents aged 3–19, the prevalence of obesity among girls was 

significantly lower in Canada than in the United States (10.4% compared with 16.7%) but not 

for Canadian boys (Figure 3). Among the youngest children (3–6 years), there was no significant 

difference in obesity prevalence between Canada and the United States for either boys or girls. 

Canadian boys (14.8%) and girls (8.7%) aged 7–12 had a lower prevalence of obesity than 

their U.S. counterparts (20.0% for boys, 18.5% for girls). Among adolescent boys aged 13–19, 

there was no significant difference in obesity prevalence, but among girls of this age group, the 

prevalence of obesity was lower in Canada (11.7%) than in the United States (18.3%). 

Figure 3. Childhood obesity among children and adolescents aged 3–19, by sex and age: Canada, 2009–2013, and 

United States, 2009–2012 Percent

Canada United States

1Use with caution (coefficient of variation between 16.6% and 33.3% for the Canadian Health Measures Survey). The coefficient of variation is obtained by 

dividing the standard error of the estimate by the estimate itself, and it is expressed as a percentage of the estimate.

2Statistically significant difference compared with Canada, p < 0.001.

NOTE: Pregnant girls are excluded.

SOURCES: CDC/NCHS, National Health and Nutrition Examination Survey, 2009–2012, and Canadian Health Measures Survey, 2009–2013.

15.5 14.8

18.1

10.4 1

10.3

8.7

11.7

2 18.3 18.3

13.3

1

11.3

2

20.0 19.8

2

16.7

11.3

2

18.5

3–19 3–6 7–12 13–19 3–19 3–6 7–12 13–19

Age group (years)

Boys Girls

0

5

10

15

20

25

30
NCHS Data Brief ■ No. 211 ■ August 2015

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Were differences seen in the prevalence of childhood obesity among the 

non-Hispanic white population between Canada and the United States?

Among non-Hispanic white boys aged 3–19, there was no significant difference between Canada 

and the United States in the prevalence of obesity (Figure 4). Similar to the overall population, 

the prevalence of childhood obesity among non-Hispanic white girls was lower in Canada than in 

the United States (10.2% compared with 14.2%). But when stratified by age group, only Canadian 

girls aged 7–12 had a significantly lower prevalence of obesity than their U.S. counterparts (8.8% 

compared with 15.2%). 

There was no difference in the prevalence of obesity between girls aged 3–6 in Canada and the 

United States and no significant difference for non-Hispanic white girls aged 13–19, which may 

be because the sample size was not large enough to detect a difference.

Figure 4. Childhood obesity among non-Hispanic white children and adolescents aged 3–19, by sex and age: Canada, 

2009–2013, and United States, 2009–2012 Percent

Canada United States

1Use with caution (coefficient of variation between 16.6% and 33.3% for the Canadian Health Measures Survey). The coefficient of variation is obtained by

dividing the standard error of the estimate by the estimate itself, and it is expressed as a percentage of the estimate.

2Statistically significant difference compared with Canada, p < 0.001.

NOTE: Pregnant girls are excluded.

SOURCES: CDC/NCHS, National Health and Nutrition Examination Survey, 2009–2012, and Canadian Health Measures Survey, 2009–2013.

15.6

1

12.5 12.1

1

19.7

10.2 1

9.5 8.8

1

11.4

15.0

9.7

15.1

17.9

2

14.2

6.8

2

15.2

17.1

3–19 3–6 7–12 13–19 3–19 3–6 7–12 13–19

Age group (years)

Boys Girls

0

5

10

15

20

25

30
NCHS Data Brief ■ No. 211 ■ August 2015

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Summary

The prevalence of childhood obesity was lower in Canada than in the United States. This 

difference was particularly pronounced in girls compared with boys. In analysis restricted to the 

non-Hispanic white population, the prevalence of obesity among boys was virtually identical in 

Canada and the United States (15.6% compared with 15.0%). Among non-Hispanic white girls, 

however, just more than 10% of girls in Canada were obese compared with a little more than 14% 

in the United States. 

Previous comparisons of childhood obesity in Canada, Mexico, and the United States through 

2004 found similar changes in childhood obesity in each of the three countries (4). Although age, 

income, and education differed somewhat within each country, the prevalence had increased in all 

three countries.

Both Canada and the United States have seen increases in childhood obesity from 1980 to the 

beginning of the 21st century, and then no recent changes in prevalence. This plateau (or in 

some cases, a decrease) in childhood obesity prevalence has been reported in at least eight other 

countries (5). Similar to childhood obesity, the prevalence of obesity among adults increased in 

Canada and the United States from the late 1980s and early 1990s to the first decade of the 21st 

century (1). 

Future data from the National Health and Nutrition Examination Survey (NHANES) and the 

Canadian Health Measures Survey (CHMS) will provide information on the direction of trends in 

obesity among youth in Canada and the United States.

Definitions

Body mass index (BMI): Weight in kilograms divided by height in meters squared, rounded to the 

nearest 10th. 

Obesity: BMI at or above the sex-specific 95th percentile of BMI for age, based on the 2000 CDC 

(Centers for Disease Control and Prevention) Growth Charts. 

Non-Hispanic white: In Canada, all respondents were asked the question: “People living in 

Canada come from many different cultural and racial backgrounds. Are you: white, Chinese, 

South Asian, Black, Filipino, Latin American, South East Asian, Arab, West Asian, Japanese, 

Korean, or Other?” Respondents could select more than one answer. Respondents who answered 

only white were used for the analysis on non-Hispanic white children and adolescents. 

In the United States, non-Hispanic white was defined based on combining participant responses 

to questions on race and Hispanic origin. Participants were asked if they identified themselves as 

Hispanic and which of the following races they considered themselves (choosing one or more):

American Indian or Alaska Native, Asian, black or African American, Native Hawaiian or Pacific 

Islander, white, or other. Respondents who answered only white and did not identify as Hispanic 

were considered non-Hispanic white. 
NCHS Data Brief ■ No. 211 ■ August 2015

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Data sources and methods

Canadian estimates are based on data from three cross-sectional surveys: the 1978–1979 Canada 

Health Survey (CHS), the 2004 Canadian Community Health Survey–Nutrition (CCHS–Nutrition), 

and cycles 2 and 3 (2009–2013) of CHMS (6). These surveys were designed to provide nationally 

representative estimates of the Canadian noninstitutionalized population (7,8). In addition to an 

interview, these surveys included direct measurement of height and weight either at the home 

(CCHS and CHS) or in a mobile examination center (CHMS). Measured height and weight data 

for individuals aged 3–19 were available on 1,974 youths in CHS, 8,994 in CCHS–Nutrition, and 

5,334 in CHMS.

United States estimates are based on data from three cycles of NHANES: NHANES II (1976–

1980), NHANES 2001–2004, and NHANES 2009–2012. NHANES, conducted by the Centers for 

Disease Control and Prevention’s (CDC) National Center for Health Statistics (NCHS), is designed 

to monitor the health and nutritional status of the United States civilian noninstitutionalized 

population (9), using highly stratified multistage probability designs. The survey consists of 

interviews conducted in participants’ homes and standardized physical examinations conducted in 

mobile examination centers, including measured height and weight. Standardized measurements 

of height and weight for youth aged 3–19 were collected from 6,687 participants in NHANES II, 

7,742 in NHANES 2001–2004, and 6,233 in NHANES 2009–2012.

For all surveys, sample weights—which account for the differential probabilities of selection, 

nonresponse, and noncoverage—are incorporated into the estimation process. For CHS, standard 

errors were estimated under the assumption of simple random sampling. For CCHS–Nutrition 

and CHMS, standard errors of the prevalence of obesity were estimated using the bootstrap 

method (10). For NHANES, standard errors were estimated by Taylor series linearization (10). 

Both the bootstrap and Taylor series linearization methods account for the design features of the 

survey. To compare the prevalence of obesity between Canada and the United States, statistical 

hypotheses were tested using Student’s t statistic and an α level of 0.05. All differences reported 

are statistically significant unless otherwise indicated. Linear trends in obesity prevalence over 

time were tested using orthogonal contrast matrices. Statistical analyses were conducted using 

SAS release 9.3 (SAS Institute, Inc., Cary, N.C.) and SUDAAN software version 11.0 (RTI 

International, Research Triangle Park, N.C.).

About the authors

Margaret D. Carroll is with CDC’s National Center for Health Statistics; Tanya Navaneelan and 

Shirley Bryan are with Statistics Canada; and Cynthia L. Ogden is with the National Center for 

Health Statistics.

References

1. Shields M, Carroll MD, Ogden CL. Adult obesity prevalence in Canada and the United States. 

NCHS data brief, no 56. Hyattsville, MD: National Center for Health Statistics. 2011.

2. Singh AS, Mulder C, Twisk JW, van Mechelen W, Chinapaw MJ. Tracking of childhood 

overweight into adulthood: A systematic review of the literature. Obes Rev 9(5):474–88. 2008.
NCHS Data Brief ■ No. 211 ■ August 2015

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3. Barlow SE, Expert Committee. Expert Committee recommendations regarding the 

prevention, assessment, and treatment of child and adolescent overweight and obesity: Summary 

report. Pediatrics 120(Suppl 4)S164–92. 2007.

4. Ogden CL, Connor Gorber S, Rivera Dommarco JA, Carroll M, Shields M, Flegal K. 

Chapter 5: The epidemiology of childhood obesity in Canada, Mexico and the United States. In: 

Moreno LA, Pigeot I, Ahrens W (editors). Epidemiology of obesity in children and adolescents: 

Prevalence and etiology. New York, NY: Springer Science+Business Media, LLC. 2011.

5. Olds T, Maher C, Zumin S, Péneau S, Lioret S, Castetbon K, et al. Evidence that the 

prevalence of childhood overweight is plateauing: Data from nine countries. Int J Pediatr Obes 

6(5–6):342–60. 2011.

6. Statistics Canada. List of other Canadian Health Measures Survey (CHMS) documents 

available. Available from: http://www23.statcan.gc.ca/imdb-bmdi/document/5071_D4_T9_V2-

eng.htm.

7. Statistics Canada. Canadian Community Health Survey–Nutrition. Available from:

http://www23.statcan.gc.ca/imdb/p2SV.pl?Function=getSurvey&SDDS=5049.

8. Giroux S. Canadian Health Measures Survey: Sampling strategy overview. Health Rep 

18(Suppl):31–6. 2007.

9. NCHS. National Health and Nutrition Examination Survey: Questionnaires, datasets, and 

related documentation. Available from: http://www.cdc.gov/nchs/nhanes/nhanes_questionnaires.

htm.

10. Wolter KM. Introduction to variance estimation. 2nd ed. New York, NY: Springer 

Science+Business Media, LLC. 2007.
NCHS Data Brief ■ No. 211 ■ August 2015

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Suggested citation

Carroll MD, Navaneelan T, Bryan S, Ogden 

CL. Prevalence of obesity among children 

and adolescents in Canada and the United 

States. NCHS data brief, no 211. Hyattsville, 

MD: National Center for Health Statistics. 

2015.

Copyright information

All material appearing in this report is in 

the public domain and may be reproduced 

or copied without permission; citation as to 

source, however, is appreciated.

National Center for Health 

Statistics

Charles J. Rothwell, M.S., M.B.A., Director

Nathaniel Schenker, Ph.D., Deputy Director

Jennifer H. Madans, Ph.D., Associate 

Director for Science

Division of Health and Nutrition 

Examination Surveys

Kathryn S. Porter, M.D., M.S., Director

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