Incidence of childhood obesity a numbers game
As many as 2,500 more children would be classified as obese if Hong Kong adopted a calculation used by the World Health Organisation, university researchers said yesterday.
However, the academics at the Chinese University of Hong Kong say the WHO standard - adopted in 2007 - is not calibrated to take into account Chinese ethnicity. It also would increase clinical workloads and create unnecessary parental anxiety.
Using the local standard that has been in place since 1993, 12.4 per cent of children aged six to 10 are classified as obese. That jumps to 14.5 using the WHO scale.
The findings are published in the latest issue of the Hong Kong Medical Journal.
The WHO hoped its standard would be adopted across the world.
Doctors said while the WHO standard would be useful in international comparative research, they would recommend the city stick to its 1993 standard.
'The use of WHO 2007 in Hong Kong could increase clinical workload and parent anxiety by identifying additional numbers,'' the researchers said, adding: 'The WHO assumed that there are no genetic differences in the growth of different ethnic populations and that the references are universally applicable.'
They pointed out that the WHO standard was based on health data collected in the United States in the 1970s using data two decades older than the 1993 data.
But regardless of the standard in use, Hong Kong Dietitians Association chairwoman Sylvia Lam See-way said child obesity was increasing. While most children became obese by eating too much fatty and sugary food, some gained weight because parents fed them too much infant growth formulas.
'Some parents treat milk formulas as vitamin pills, but growth formulas are only suitable for those who do not receive enough nutrients from their daily diet,' she said.
Lam said the energy levels of some growth formulas were two times as much as skimmed milk, and urged parents to consult dietitians before using them.
She added that it was also important to have regular exercise of 30 to 45 minutes a day.
Overweight children are more at risk of suffering from heart problems, diabetes and back pain, previous research has shown.