In the UK
It is difficult to get an accurate figure for the prevalence of childhood obesity in the UK as it represents something of a moving target. There has been a well-documented increase in the numbers of overweight and obese children over the last 10 years (
see link), and this, as well as differences in the ages of children measured and in the definitions of overweight and obesity used, means that different studies give different figures (see Table).
The 2001 Health Survey found that 8.5% of 6 year olds rising to 15% of 15 year olds had a BMI greater than the 95th centile for their age compared to the expected 5%.
Chin and Rona (Chinn and Rona 2001), analysed the results of the National Study of Health and Growth according to the recently agreed international cut-offs for BMI in children. This study measured height and weight in 30 755 primary school children aged 4-11 years. They found that in 1994 1.7% English boys and 2.1% Scottish boys and 2.6% English girls and 3.2% Scottish girls were obese. The prevalence of overweight was 9.0% English boys and 10.0% Scottish boys and 13.5% and 15.8% of English and Scottish girls respectively. Their definition of overweight includes those who are also obese.
Reilly and Dorosty, (Reilly and Dorosty 1999) in a study in 1996 of 2630 English children aged 6-15 years, found that 10% of 6 year olds (rather than the expected 5%) rising to 17% of 15 year olds had a BMI greater than the 95th centile for their age. In addition, 22% of 6 year olds rising to 31% of 15 year olds had a BMI greater than the 85th centile for their age.
Reilly, Dorosty and Emmett (Reilly, Dorosty et al. 1999) in a cohort study of children born in 1991-92, found that at age 2 years 6.0% weighed more than the 95th centile for their age, at age 4 years 6.7% weighed more than the 95th centile and at age 5 years 7.2% weighed more than the 95th centile (compared to the expected 5%). The prevalence of overweight was 15.8% (at 2 years), 20.3% (at 4 years) and 18.7% (at 5 years) compared to the expected 15%.
Rudolf et al (Rudolf, Sahota et al. 2001) in a cohort study in Leeds measured 694 primary school children in 1996, 1997 and 1998. They found that 22% of boys and girls were overweight, compared to the expected 15% and that 12% of boys and 11% of girls were obese compared to the expected 5%. They also found that the prevalence of overweight and obesity increased as the children got older.
McCarthy, Ellis and Cole (McCarthy, Ellis et al. 2003) analysed the findings of the National Diet and Nutrition Survey for 776 11-16 year old children carried out in 1997. They defined obesity as greater than 98th centile and overweight as greater than 91st centile. These are similar to the recently agreed international cut-offs. They found 10% of boys and 8.3% of girls aged 11-16 were obese and 20.6% of boys and 17.3% of girls were overweight.
Bundred, Kitchiner and Buchan (Bundred, Kitchiner et al. 2001) analysed the results of health visitors data on children aged between 2 and 4 years in Liverpool. They found that in 1998, 9.2% of children weighed more than the 95th centile (compared to the expected 5%) and 23.6% weighed more than the 85th centile (compared to the expected 15%).
These studies show that the prevalence of obesity increases as children get older. This is consistent with data on adult obesity which shows a similar trend up to about age 65 years. These studies suggest that the prevalence of obesity in the UK ranges from about 7% to 10% and that about 20% of children are overweight.
In Europe
The International Obesity Task Force (IOTF) has collected information on the prevalence of obesity in European children aged around 10 years (
click). They found that the prevalence of overweight and obesity ranged from 10% in Slovakia to over 35% in Italy, using the international definitions proposed by Cole at al (Cole, Bellizzi et al. 2000).
References
Bundred, P., D. Kitchiner, et al. (2001). "Prevalence of overweight and obese children between 1989 and 1998:population based series of cross-sectional studies."
BMJ 322: 326.
Chinn, S. and R. J. Rona (2001). "Prevalence and trends in overweight and obesity in three cross-sectional studies of British children, 1974-1994."
BMJ 322: 24-26.
Cole, T., M. Bellizzi, et al. (2000). "Establishing a standard definition for child overweight and obesity worldwide: international survey."
BMJ 320: 1240-1243.
IOTF, I. O. T. F. Obesity in Europe.
McCarthy, H. D., S. M. Ellis, et al. (2003). "Central overweight and obesity in British youth aged 11-16 years:cross-sectional surveys of waist circumference."
BMJ 326: 624.
Reilly, J. R. and A. R. Dorosty (1999). "Epidemic of obesity in UK children."
The Lancet 354: 1874.
Reilly, J. R., A. R. Dorosty, et al. (1999). "Prevalence of overweight and obesity in British Children: cohort study."
BMJ 319: 1039.
Rudolf, M. C., P. Sahota, et al. (2001). "Increasing prevalence of obesity in primary school children: cohort study."
BMJ 322: 1094-1095.
