Related Experiment Videos
International definitions of overweight and obesity for children: a lasting solution?
1Department of Public Health Sciences, King's College London, 5th Floor Capital House, 42 Weston Street, London SE1 3QD, UK. sue.chinn@kcl.ac.uk
Insights
International child obesity definitions may overestimate prevalence in the UK. New UK-specific body mass index (BMI) cut-offs are compatible with UK data and better reflect trends in overweight children.
Area of Science:
- Pediatric Endocrinology
- Public Health
- Biostatistics
Background:
- Established international definitions for childhood overweight and obesity (2000) were based on averaged data from six countries.
- The applicability of these international definitions to UK children remains unclear, potentially lacking advantages over UK-specific data.
Purpose of the Study:
- To compare international child overweight and obesity cut-off points with alternative definitions derived from UK 1990 reference data.
- To assess the compatibility and accuracy of international versus UK-based BMI classifications for British children.
Main Methods:
- Two cross-sectional surveys in 1984 and 1994 included approximately 6000 white children (aged 4-11) from 22 English primary school areas.
- Height and weight were measured to calculate body mass index (BMI), with children classified using both international and proposed UK cut-off points.
Main Results:
- International cut-off points exaggerated gender differences in overweight/obesity prevalence by up to 7% compared to UK data and were incompatible with UK BMI reference charts.
- Using proposed UK cut-off points, overweight prevalence in boys increased from 10.2% (1984) to 13.8% (1994), contrasting with 5.4%-9.0% under the international definition.
Conclusions:
- International definitions for childhood overweight and obesity have limitations due to averaged multi-country data and reference age selection.
- The presented UK cut-off points are compatible with current UK reference curves and offer a more accurate assessment for the UK population.
Background:
Definitions of overweight and obesity for children were published in 2000, derived by averaging the centiles of six countries equivalent to body mass index (BMI) at age 18 years of 25 and 30. For use in the UK it is unclear whether these present an advantage over equivalent definitions based on UK data.
Aim:
To compare the recently published international cut-off points for overweight and obesity in children with alternative cut-off points based on the UK 1990 reference data.
Subjects And Methods:
Around 6000 white children aged 4-11 years from primary schools in 22 areas in England were measured in two cross-sectional surveys, in 1984 and 1994. Measurements included height and weight, from which BMI was calculated. Each child was classified as overweight or obese according to each cut-off point.
Results:
The proposed international cut-off points exaggerate the difference in prevalence of overweight and obesity between English boys and girls in comparison to comparable measures based on UK data by up to 7%, and are not compatible with the UK reference charts for BMI. Using proposed UK cut-off points the prevalence of overweight in boys was 10.2% in 1984, rising to 13.8% in 1994, compared to 5.4 to 9.0% using the international definition.
Conclusion:
The limitations of the international definitions, due to averaging data from different countries and the choice of reference age, need to be known. The UK cut-off points here presented are compatible with the current UK reference curves.