Growth of South African Indian schoolchildren in different social classes

Assessment of linear growth of affluent urban Pakistani adolescents according to CDC 2000 references

BACKGROUND

The appropriateness of using international reference data for assessing growth of children and adolescents from developing countries has been debated. If the growth performance in at least those sections of the society that may be considered affluent has reached the levels represented by the international reference, the case for adoption of the NCHS reference would be strong. Findings from studies in younger children indicate appropriateness of these standards but data from older children are lacking.

AIM

The study aimed to compare the linear growth of affluent Pakistani adolescents living in Karachi with the NCHS reference so as to assess the appropriateness of using these standards for assessing the growth status of Pakistani adolescents.

SUBJECTS AND METHODS

Data were collected from 876 girls and 819 boys aged 10-15 years studying in well known and established affluent urban public schools in Karachi. A portable stadiometer (Minimeter by CMS, London) was used for measuring heights. Heights were compared using the United States Center for Disease Control (CDC 2000) reference values to assess growth status.

RESULTS

The mean ages of boys and girls were 12.82 and 12.63, respectively. Mean Height for Age Z score (HAZ) (-0.02) was very close to CDC 2000 reference values but the growth pattern was not similar. Younger children were relatively taller and the older children were shorter than CDC standards. Mean HAZ scores for 10, 11, 12, 13, 14 and 15-year-old boys and girls were 1.12 and 1.03, 0.54 and 0.55, 0.47 and 0.26, 0.29 and -0.21, -0.08 and -0.64, -0.19 and -0.53, respectively. The mean HAZ for boys (0.12) was slightly higher and that for girls slightly lower (HAZ = -0.14) than the reference population. Even among the relatively affluent group of children studied HAZ scores increased with relative socio-economic status.

CONCLUSIONS

Although in terms of averages for 10-15-year-old boys and girls the height status was not very different from CDC standards, the growth curves of Pakistani children was slightly different from CDC 2000 standards. Further studies are needed to assess the appropriateness of using international growth standards for assessing height status of Pakistani adolescents.

Body dimensions, exercise capacity and physical activity level of adolescent Nandi boys in western Kenya

The aim of this study was to characterize untrained Nandi boys (mean age 16.6 years) from a town (n = 11) and from a rural area (n = 19) in western Kenya (altitude approximately 2000 m.a.s.l.) in regard to their body dimensions, oxygen uptake and physical activity level. The town boys had a mean maximal oxygen uptake (VO(2 max)) of 50 (range: 45-60) mL kg(-1) min(-1), whereas the village boys reached a value of 55 (37-63) mL kg(-1) min(-1) ( p<0.01) in VO(2 max). The running economy, determined as the oxygen cost at a given running speed, was 221 mL kg(-1) km(-1) (597 mL kg(-0.75) km(-1)) for town as well as for village boys. The body mass index (BMI) was very low for town as well as for village boys (18.6 vs 18.4 kg m(-2)). The daily mean time spent working in the field during secondary school and doing sports were significantly higher in village boys compared to town boys (working in the field: 44.2 (0-128) vs 1.3 (0-11) min, p<0.01; sports: 32.0 (11-72) vs 12.8 (0-35) min, p<0.01, respectively). A positive correlation between the daily time spent doing sports and VO(2 max) was found when pooling the data from the town and the village boys (R = 0.55, p<0.01). It is concluded that the body dimensions of adolescent Nandi town and village boys corresponds well with findings in Kenyan elite runners. They are very slender with relatively long legs. In addition, the VO(2 max) of the village boys was higher than that of the town boys, which is probably due to a higher physical activity level of the village boys during secondary school.

Maximal genetic potential for adult stature: is this aim desirable?

Current nutrition theory holds that maximization of human growth and stature is a desired anthropometric outcome. However, some evidence demonstrates that lower energy intakes may actually confer a degree of future protection against degenerative processes, particularly atherosclerosis and cancer.

Body image and eating behaviour in interethnic adolescent girls

Reports of major dissatisfaction among adolescent girls over body shape and their associated eating behaviour, prompted determining anthropometric and questionnaire studies on series of rural and urban black, Indian, and white girls aged 14-19 years. Variables were concern over weight, desired weight loss, also practices regarding binge eating, fasting, vomiting and laxative use. Black girls have low weight-for-age, yet experience more obesity than white girls; yet weight reduction, although desired, is seldom seriously attempted. Indian girls have low weight-for-age, principally for genetic, not social class, reasons; they also, even some underweight, desired weight reduction. White girls are also dissatisfied, although less acutely than girls in the US. The current attitudes of South African adolescent girls, apart from extremes, are unlikely to seriously prejudice their health.