IOTF’s champion Tim Cole celebrates a life in statistics
The creator of the International Obesity TaskForce (IOTF) definitions of overweight and obesity in childhood celebrated his life as a medical statistician at the UCL Great Ormond Institute of Child Health in London in September.
Professor Tim Cole, now semi-retired, developed growth charts for the UK, which were published as official guides for health professionals and parents in the 1990s, and he followed this with international growth curves – including specific cut-off points for overweight and obesity for ages between 2 years and 18 years, for girls and boys – produced for IOTF.
These were published in 2000, and followed up with definitions for thinness in 2007, and extended for higher levels of overweight in 2012, available for boys and for girls.
IOTF subsequently became part of the World Obesity Federation, but the definitions of child overweight and obesity remain known as the IOTF (or Cole) BMI cut-offs. These IOTF cut-offs have remained as standard around the world and are used in the Institute for Health Metrics’ Global Burden of Disease estimates.
In 2006, the World Health Organization revised its growth charts and produced an alternative set of cut-offs and joined with IOTF to encourage researchers to report survey results using both IOTF and WHO cut-off criteria to allow continuity of data from past surveys. In 2023, Professor Cole produced a set of algorithms allowing prevalence estimates using the WHO criteria to be converted to prevalence estimates using IOTF criteria, and vice versa.
Obesity classification
There are various means through which you can screen for obesity, the most widely-used method being the Body Mass Index (BMI).
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