Mary CJ Rudolf, Pinki Sahota, Julian H Barth, Jenny Walker.

Address for correspondence:

Dr MCJ Rudolf
Community Paediatrics
Leeds Community and Mental Health Trust
Belmont House
3-5, Belmont Grove
Leeds LS2 9NP

Tel: 0113 392 6352
Fax: 0113 392 5169

P Sahota
Leeds Metropolitan University

J H Barth
J Walker
Leeds General Infirmary

Acknowledgements:

This research was supported by a grant from Northern and Yorkshire Region Research and Development Unit

INTRODUCTION

There is much concern that obesity is proving to be one of the greatest public health issues of the present time, with increasing evidence that for much of the population obesity has its roots in the childhood years. Recently, reports have appeared regarding the rising levels of overweight and obesity amongst children. Earlier this year Reilly et al reported that even by the age of 5 years there was significantly more obesity than that expected from the national standards¹, and that this persisted into the teenage years².

METHODS, PARTICIPANTS AND RESULTS

From 1996 to 1999 children in 10 Leeds primary schools participating in APPLES, a health promotion programme³, were methodically measured by an expert auxologist(JW). Children in Years 3 and 4 (age 7-9 years) were measured in the July of 1996, 1997 and 1998. Sociodemographic measures suggested they were marginally more advantaged than average for Leeds, with between 1- 42% ethnic minority pupils, and 7-29% entitled to free school meals (a measure of social disadvantage).

Height was measured to 0.1cm using a free standing Magnimeter stadiometer. Weights were without shoes or jumpers and recorded to 0.1kg. The mean of three triceps measurements were taken⁴. BMI (wt/ht²) was calculated and measurements converted to SDscores using the revised 1990 reference standards for BMI⁶, and the Tanner Whitehouse (1962)⁴ standards for skinfolds. The following conventional cutoffs were applied: BMI SD score >1.04 (85^th centile) for overweight, and >1.64 (95^th centile) for obese. These definitions set the percentage expected to be overweight at 15% and obese at 5%. Observed levels were compared with expected using Chi squared goodness of fit test.

All but 21 children consented to participate. 608 children were measured in 1996, of whom 540 were remeasured in 1997, and 499 in 1998 (some of whom were not measured in 1997). In addition 86 new children joined the study in 1997 and 1998. In total 694 children were measured, resulting in 1762 measurements over the course of the study.

Tables1 shows the proportion of children with BMI and triceps skinfold measurements above the 85^th and 95^th centiles according to age. A significant increase in the proportion of overweight and obese children was observed from the age of 9 to 11 years.

COMMENT

The results presented here add to reports published earlier this year and indicate that there has been a remarkable rise such that one in five nine year olds are overweight increasing to as many as one in three eleven year old girls. Our data has added new information in that triceps skinfold measurements have also been collected. Rather surprisingly, given the BMI levels, these measures were not significantly in excess of that expected from the 1962 standards. Skinfold measures therefore need to be validated in a larger study, but if confirmed suggest that a different pattern of obesity may be emerging.

The new British Growth standards were developed in 1990 in response to an appreciation that children had demonstrated a secular increase in both height and weight, and that the previous standards, developed in the 1950s were no longer appropriate for use in Britain today. Now, less than a decade after the new standards were introduced, it has become evident that the standards no longer reflect the distribution of weight in British school children.

The cause for concern is twofold. Firstly cohort studies show that obesity may track from childhood to adulthood where morbidity is very evident. Furthermore obesity in adolescence is of itself associated with increased morbidity and mortality in adult life independent of adult body weight. This study lends further support to reports that levels of obesity in Britain are increasing at a dramatic rate in primary schools children, that the triceps skinfold measures need to be revalidated, and that there is urgency required to address this major public health issue in young children.

REFERENCES

1. Reilly JJ, Dorosty AR, Emmett PM. Prevalence of overweight and obesity in British children: cohort study. BMJ 1999; 319: 1039
2. Reilly JJ, Dorosty AR. Epidemic of obesity in UK children. Lancet 1999; 354: 1874-5
3. Sahota P, Rudolf MCJ, Dixey R, Hill AJ, Barth JH. APPLES: a school-based intervention to reduce obesity risk factors. Int Jnl Obes 1998; 22:(suppl 3) S62

4. Tanner JM, Whitehouse RH. Standards for subcutaneous fat in British children. Percentiles for thickness of skinfolds over triceps and below scapula. BMJ 1962; I: 446-50
5. Cole TJ, Freeman JV, Preece MA. Body mass index reference curves for the UK, 1990. Arch Dis Child 1995; 73: 25-29.

TABLE 1: BMI SCORES AND TRICEPS SKINFOLD MEASURES IN LEEDS PRIMARY SCHOOL CHILDREN: The prevalence of overweight and obesity are shown using the definition of >85^th centile for overweight and >95^th centile for obese. Using BMI. there is an increase in expected numbers of overweight and obese children from the age of 9 years for both girls and boys.
 

⁺Each year group was taken as the year to the next birthday (ie "seven" year olds included children aged 7.0 to <8.0 years).

Frequencies significantly different from expected values of 15% (overweight) and 5% (obesity) at

* p<0.01, ** p<0.001