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. 2012 Jul 10;184(10):E539–E550. doi: 10.1503/cmaj.110797

Table 3:

Comparison of the anthropometric characteristics of children according to whether the CDC or WHO growth curves are used as the reference

Characteristic 9-year-olds 13-year-olds 16-year-olds



CDC WHO p value CDC WHO p value CDC WHO p value
Boys n = 381 n = 416 n = 407

BMI percentile, mean (SD) 53.8 (31.5) 56.6 (32.5) < 0.0001 57.6 (29.1) 60.1 (29.9) < 0.0001 57.8 (27.8) 58.7 (28.3) < 0.0001

BMI z score, mean (SD)* 0.12 (1.1) 0.35 (1.4) < 0.0001 0.26 (1.0) 0.43 (1.2) < 0.0001 0.28 (1.0) 0.38 (1.1) < 0.0001

BMI category, no. (%)

 Underweight 25 (6.6) 20 (5.2) < 0.0001 21 (5.0) 21 (5.0) 0.002 11 (2.7) 10 (2.5) 0.006

 Normal 264 (69.3) 251 (65.9) < 0.0001 295 (71.0) 275 (66.1) 0.002 306 (75.2) 296 (72.7) 0.006

 Overweight 57 (15.0) 66 (17.3) < 0.0001 54 (13.0) 73 (17.5) 0.002 48 (11.8) 65 (16.0) 0.006

 Obese 35 (9.2) 44 (11.5) < 0.0001 46 (11.0) 47 (11.3) 0.002 42 (10.3) 36 (8.8) 0.006

Girls n = 398 n = 400 n = 464

BMI percentile, mean (SD) 51.7 (31.2) 54.8 (31.8) < 0.0001 58.1 (29.1) 57.5 (30.7) 0.4 55.8 (28.2) 54.9 (29.5) 0.0002

BMI z score, mean (SD)* 0.05 (1.1) 0.25 (1.3) < 0.0001 0.26 (1.1) 0.32 (1.3) < 0.0001 0.19 (0.9) 0.23 (1.1) < 0.0001

BMI category, no. (%)

 Underweight 31 (7.8) 25 (6.3) 0.001 15 (3.7) 17 (4.3) 0.04 13 (2.8) 13 (2.8) 0.04

 Normal 283 (71.1) 274 (68.8) 0.001 293 (73.3) 281 (70.3) 0.04 352 (75.9) 340 (73.3) 0.04

 Overweight 48 (12.1) 62 (15.6) 0.001 53 (13.3) 64 (16.0) 0.04 73 (15.7) 86 (18.5) 0.04

 Obese 36 (9.0) 37 (9.3) 0.001 39 (9.7) 38 (9.5) 0.04 26 (5.6) 25 (5.4) 0.04

Note: BMI = body mass index, CDC = Centers for Disease Control and Prevention, SD = standard deviation, WHO = World Health Organization.

*

Distance (measured in standard deviations) from the mean BMI of children of the same age and sex.

Percentages may not add up to 100% owing to rounding. CDC and WHO both define underweight as BMI < 5th percentile and normal as at or above the 5th percentile and below the 85th percentile. CDC defines overweight as a BMI at or above the 85th percentile and below the 95th percentile, and obese as BMI ≥ 95th percentile. WHO defines overweight as at or above the 85th percentile and below the 97.7th percentile, and obese as BMI ≥ 97.7th percentile.