Article Text

Download PDFPDF
The TRENDS Project: development of a methodology to reliably monitor the obesity epidemic in childhood
  1. M C J Rudolf1,
  2. R Levine2,
  3. R Feltbower3,
  4. A Connor4,
  5. M Robinson1
  1. 1University of Leeds and East Leeds PCT, Leeds, UK
  2. 2The TRENDS Project, East Leeds PCT, Leeds, UK
  3. 3Centre for Epidemiology and Biostatistics, University of Leeds, Leeds, UK
  4. 4School Nurse Service, East Leeds PCT, Leeds, UK
  1. Correspondence to:
    Professor Mary Rudolf
    Community Paediatrics, Belmont House, 3–5, Belmont Grove, Leeds, LS2 9DE, UK; Mary.rudolf{at}


Aims: The government has set a target to halt the rise in childhood obesity in those aged under 11 by 2010, but no system is in place to ascertain if this has been achieved. We aimed to develop a simple and reproducible methodology to monitor trends in childhood obesity.

Methods: A purposive sample of 10 primary schools and three secondary schools was selected. Children were measured with parental “opt out” consent in reception class, year 4, and year 8 (ages 5, 9, and 13 years, respectively). Measurements were compared with those obtained locally in 1996–2001. Calculations were then performed to ascertain the sample size required to confidently identify a halt in the rise in obesity using three growth measures.

Results: A total of 999 children were measured with ascertainment of 95% in primary and 85% in secondary schools. The proportion of overweight and obese children aged 9 and 13 years had increased since 1996–2001, although only 9 year olds showed a significant rise. A general trend of an increase in obesity was observed with increasing age. Calculations showed that 1900–2400 children per age group are needed to detect a halt in the rise in obesity based on mean body mass index (BMI) standard deviation scores (SDS) by 2010 with 90% power, whereas 4200–10 500 children are needed for other measures.

Conclusion: We have developed a simple, cost effective methodology for accurately measuring the epidemic and recommend the use of mean BMI SDS for demonstrating if a halt has been achieved.

  • BMI, body mass index
  • IOTF, International Obesity Task Force
  • SDS, standard deviation scores
  • SES, socioeconomic status
  • childhood obesity
  • monitoring
  • screening

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Published Online First 14 December 2005

  • Competing interests: none declared

Linked Articles

  • Atoms
    Howard Bauchner