One million skinfolds: secular trends in the fatness of young people 1951-2004.
OBJECTIVE
There are abundant data on secular trends in the body mass index (BMI) of children. However, BMI is an imperfect index of fatness, whereas skinfold thicknesses provide a more direct measure. This study aims to meta-analyse historical studies of triceps and subscapular skinfold thicknesses in young people aged 0-18 years in developed countries.


METHODS
A total of 154 studies conducted between 1951 and 2003 were analysed, covering 2390 reports at the age x sex x country level, and more than 458,547 young people from 30 developed countries. Percentage body fat (% BF) was estimated using the Slaughter equations. The distribution of fat on the body was indexed by the triceps/subscapular (T/S) ratio. The skewness of skinfold distributions was operationalized by the coefficient of variation and the mean-median difference.


RESULTS
There have been increases in triceps and subscapular skinfold thicknesses, at the rate of 0.4-0.5 mm per decade over the period 1951-2003. % BF has been increasing at the rate of 0.9% BF per decade. The distribution of fat on the body, as indexed by the triceps/subscapular (T/S) ratio, has become more central. There has been an increasing positive skew in the distribution of subcutaneous fat thickness in the population.


CONCLUSIONS
These trends describe very unfavourable changes in the body composition of young people, foreshadowing a potential increase in the incidence of cardiovascular and metabolic disease.
Olds
T S
TS
Sansom Institute, School of Health Sciences, Physical Education, Exercise and Sport Studies, University of South Australia, Adelaide, South Australia, Australia. timothy.olds@unisa.edu.au
D050154:Adiposity; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D007223:Infant; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000266:history*; D012885:Skinfold Thickness; D050151:Subcutaneous Fat