A little bit chubby, overweight or clinically obese? The most reliable way of gauging your child's weight is by working out their BMI (Body Mass Index), which takes weight and height into account. A BMI of over 30 is generally used to indicate obesity; bear in mind, however, that BMI calculators are designed for adults and don't take into account age and sex. BMI percentile charts (see below) should be used to pinpoint weight problems in children.
To calculate your child's BMI:
Weight (kg) / height (metres) squared
For a child weighing 24kg who is 1 metre 20 cm tall:
24 / (1.2 x 1.2) = BMI of 16.6
To view the international cut-off points for overweight and obesity from the British Medical Journal, click here.
Another useful link:
World Health Organization growth charts: