Table 3.
Prevalence of four categories of weight status (underweight, healthy, overweight and obesity) using four international references among boys, KwaZulu-Natal, South Africa
| Grade 1 (age 7 years) | Grade 5 (age 11 years) | Grade 9 (age 15 years) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Weight status | Method | n | % | 95 % CI | n | % | 95 % CI | n | % | 95 % CI |
| Underweight* | BMI-for-age (WHO 2007)( 24 ) | 9 | 3·4 | 1·8, 6·4 | 12 | 5·2 | 3·0, 8·8 | 11 | 6·2 | 3·5, 10·8 |
| BMI-for-age (Cole-IOTF)( 27 , 29 ) | 42 | 16·0 | 12·0, 20·9 | 30 | 12·9 | 9·2, 17·8 | 26 | 15·8 | 11·0, 22·1 | |
| Weight-for-age (NCHS/WHO)( 25 ) | 16 | 6·2 | 3·8, 9·8 | 9 | 3·9 | 2·1, 7·2 | 12 | 7·6 | 4·4, 12·8 | |
| Body fat % (McCarthy 2006)( 30 ) | 23 | 8·8 | 5·9, 12·8 | 114 | 48·7 | 42·4, 55·1 | 110 | 60·4 | 53·2, 67·3 | |
| Healthy weight† | BMI-for-age (WHO 2007)( 24 ) | 230 | 87·5 | 82·9, 90·9 | 202 | 86·7 | 81·7, 90·5 | 152 | 85·9 | 80·0, 90·3 |
| BMI-for-age (Cole-IOTF)( 27 , 29 ) | 212 | 80·6 | 75·4, 84·9 | 191 | 82·0 | 76·5, 86·4 | 129 | 78·2 | 71·3, 83·8 | |
| Weight-for-age (NCHS/WHO)( 25 ) | 211 | 81·2 | 76·0, 85·4 | 213 | 91·8 | 87·6, 94·7 | 138 | 87·3 | 81·3, 91·7 | |
| Body fat % (McCarthy 2006)( 30 ) | 195 | 74·4 | 68·8, 79·3 | 107 | 45·7 | 39·5, 52·1 | 66 | 36·3 | 29·6, 43·5 | |
| Overweight‡ | BMI-for-age (WHO 2007)( 24 ) | 22 | 8·4 | 5·6, 12·3 | 11 | 4·7 | 2·7, 8·3 | 10 | 5·7 | 3·1, 10·1 |
| BMI-for-age (Cole-IOTF)( 27 , 29 ) | 8 | 3·0 | 1·6, 5·9 | 7 | 3·0 | 1·5, 6·1 | 8 | 4·9 | 2·5, 9·3 | |
| Weight-for-age (NCHS/WHO)( 25 ) | 25 | 9·6 | 6·6, 13·8 | 8 | 3·5 | 1·8, 6·7 | 7 | 4·4 | 2·2, 8·9 | |
| Body fat % (McCarthy 2006)( 30 ) | 36 | 13·7 | 10·1, 18·4 | 5 | 2·1 | 0·9, 4·9 | 1 | 0·6 | 0·1, 3·1 | |
| Obese§ | BMI-for-age (WHO 2007)( 24 ) | 2 | 0·8 | 0·2, 2·7 | 8 | 3·4 | 1·8, 6·6 | 4 | 2·3 | 0·9, 5·7 |
| BMI-for-age (Cole-IOTF)( 27 , 29 ) | 1 | 0·4 | 0·1, 2·1 | 5 | 2·2 | 0·9, 4·9 | 2 | 1·2 | 0·3, 4·3 | |
| Weight-for-age (NCHS/WHO)( 25 ) | 8 | 3·1 | 1·6, 6·0 | 2 | 0·9 | 0·2, 3·1 | 1 | 0·6 | 0·1, 3·5 | |
| Body fat % (McCarthy 2006)( 30 ) | 8 | 3·1 | 1·6, 5·9 | 8 | 3·4 | 1·7, 6·6 | 5 | 2·8 | 1·2, 6·3 | |
IOTF, International Obesity Taskforce; NCHS, National Center for Health Statistics.
*Underweight: WHO 2007 = Z score of <−2; IOTF = equivalent to BMI at age 18 years of <18·5 kg/m2; NCHS/WHO = Z-score of <−2; McCarthy 2006 = body fat % ranging from 0 to 12 % depending on age.
†Healthy weight: WHO 2007 = Z score of ≥−2 and ≤+1; IOTF = equivalent to BMI at age years 18 of 18·5–24·9 kg/m2; NCHS/WHO = Z-score of ≥−2 and ≤+1; McCarthy 2006 = body fat % ranging from 10 to 23 % depending on age.
‡Overweight: WHO 2007 = Z-score of >+1; IOTF = equivalent to BMI at age 18 years of 25·0–29·9 kg/m2; NCHS/WHO = Z-score of >+1 and ≤+2; body fat % = ranging from 20 to 28 %, depending on age.
§Obese: WHO 2007 = Z-score of >+2; IOTF = equivalent to BMI at age 18 years of ≥30·0 kg/m2; NCHS/WHO = Z-score of >+2; McCarthy 2006 = body fat % ranging from 24 % depending on age.