Obesity in a cohort of black Jamaican children as estimated by BMI and other indices of adiposity

Abstract

Objective: To examine the relationships of body mass index (BMI) to obesity indices derived from anthropometry and to determine tracking of overweight between late childhood and early adolescence, in a cohort of children with mixed nutritional history. We also compared identification of overweight children using The International Obesity Task Force (IOTF) BMI cut-off points with skinfolds. Design: Prospective study. Setting: Kingston, Jamaica. Subjects: A total of 306 children examined at 7 -8 y and at 11 -12 y. Measurements: Triceps (TSF) and subscapular skinfolds (SSF), height and weight were measured. The sum of the skinfolds (sum SF), BMI, percentage body fat (%fat) and fat mass (FM) were calculated. Pubertal stage was assessed at 11 -12 y. Results: Overweight increased from 3.5 to 9.5% over the follow-up period. BMI was better correlated with the other indices of adiposity in girls and in the older age group. BMI tracking over follow up was high. In regression analysis BMI explained 52 and 61% of the variance in FM in boys and girls at 7 -8 y. This increased to 69% in both sexes at 11 -12 y. Using the IOTF cut-off points BMI had low sensitivity to identify children > 85th percentile of the NHANES references for SSF. The sensitivity for those assessed by TSF and sum SF was higher, but between 14 and 30% of the children were misclassified. The specificity of BMI was high. Conclusions: Adiposity increased over follow-up. Although the cohort remained relatively lean BMI rank among the fattest children was maintained. Girls were fatter than boys, reflecting adult obesity patterns. Children identified as overweight by the IOTF BMI cut-off points are likely to have high body fatness. However the BMI cut-off points may not identify many children with high body fatness. Sponsorship: Nutricia Research Foundation and the Wellcome Trust (grant no. 049235=Z=96=Z).

Diagnosis of overweight and obesity in adolescents from the 1993 Pelotas Birth Cohort Study, Rio Grande do Sul State, Brazil: comparison of two diagnostic criteria

“…In relation to specificity, Gaskin et al 16 showed similar results in Jamaican youth when comparing over-weight prevalence according to the IOTF classification 5 with that found by subscapular skinfold. However, the study showed low sensitivity, classifying 25% of obese adolescents as normal (false negatives).…”

“…However, as in the current study, they found high specificity with the IOTF method 5 , independently of the sexual maturation period. The differences observed between the studies may result from the criterion used as the gold standard, since our study used the 85 th percentile and skinfolds, while Chiara et al 14 and Gaskin et al 16 used only the subscapular skinfold. The choice of method to estimate the percentage of body fat is a potential source of variation in sensitivity and specificity.…”

Several anthropometric predictors of cardiovascular disease in central Slovakian adults: socioeconomic and educational differences

“…BMI and WHR and constitutes an increased risk for several adult degenerative diseases (18). Inadequate nutrition in early childhood (more common among socially disadvantaged populations) may serve to potentiate adult obesity-related disease (19).…”

Misperceptions, inactivity and maternal factors may drive obesity among Barbadian adolescents

“…Selection of appropriate tools is complicated by the fact that most tools in use are proxy measures that do not actually measure adiposity 15 and vary in validity 16 depending on the age and ethnicity of the population 17 . Body mass index (BMI) is one such measure 1,2 where, in addition to the difficulty of selecting appropriate equations for calculating body composition from BMI, there is the added effect of differences in the rate of maturation and its effect on body composition 15 .…”