Children’s weight issues Part I - Is your child overweight or obese?

As a nation, Australians are losing the battle of the bulge and it's most evident with our kids. Across all age groups and backgrounds, Australian children are getting fatter.

The size of Australia's problem

Consider these statistics:

• Childhood obesity in Australia has tripled in the past 10 years, with 19 per cent of boys and 21 per cent of girls now overweight or obese.
• A NSW Central Coast survey reports that one in 10 boys are obese and around one in 6 are overweight. In total, more than 25% of children weighed more than they should.
• Overweight children are highly likely to end up being overweight as adults and to experience the health problems associated with adult obesity like type 2 diabetes, heart disease, gallstones, gout and sleep apnoea.
• Doctors have seen an increase in the number of children treated for type 2 diabetes associated with overweight, poor diet and lack of exercise. This is the type of diabetes that used to occur almost always in people over 50.
• If one parent is obese, it's been estimated that the probability of a child being obese is 40 per cent. If both are obese, the probability rises to 80 per cent, compared to 7 per cent for neither being obese.
• Obese children are exposed to discrimination, ridicule, social rejection and isolation and can suffer low self-esteem and depression.
• Over 80 per cent of parents with overweight children and close to 50 per cent of those with obese children don't see their child's overweight as a worry. It appears that parents either aren't concerned (believing they'll 'grow out of their puppy fat') or aren't aware of the health risks of being too heavy.

Is your child is overweight?

The Body Mass Index formula (BMI) has been adapted for children. Because they are growing, the cut-off figures to classify kids as overweight have to change with age. So a 5-year old would be medically classified as overweight if his or her BMI was over 17, while a 16-year old who is almost an adult would be overweight with a BMI over 24 (for adults, the BMI would have be 25 or higher to be overweight and 30 or higher to be obese). 

Calculate your child's BMI

To calculate BMI, divide your child's weight (in kilograms) by their height (in metres) squared. Use a calculator to work out:

BMI = weight (in kg) divided by
height (m) x height (m)

For example, a 10 year old boy who is 140 cm tall (4'7") and weighs 45 kg would have a BMI of 22.9 (45 divided by 1.4 x 1.4) which would mean they are technically overweight.

How does your child's BMI compare?

Below are the international cut off points for body mass index (BMI) for overweight (25 kg/m2) and obesity (30 kg/m2) for boys and girls between 2 and 18 years. Once you have calculated your child's BMI, use the table to choose the age group that is closest to their current age. Compare their BMI to the cut-off figures for overweight and obese. Children with a BMI greater than the cut -off figures would then be considered to be overweight or obese.

What to do now?

• For advice on what to do about your child's weight, go to Children's weight issues part 2.
• If your child has been overweight for some time or attempts at weight control have been unsuccessful, visit an Accredited Practicing Dietitian (APD) with expertise in child health or paediatrics. For your nearest APD, go to the website of the Dietitians Australia and choose Find a Dietitian or telephone 1800 812 942.