https://www.gosh.nhs.uk/conditions-and-treatments/general-health-advice-children/eat-smart/obesity-lowdown/
Obesity lowdown
Obesity is a medical term. It is used to describe kids and adults who carry 20 per cent extra body weight.
This extra weight could cause serious health problems at some point. If not treated at an early stage, being obese can cause you problems such as arthritis, cancer, heart disease, stroke, diabetes and depression.
How do you know if you're obese?
Sometimes working out if you are obese can be hard. You might feel fine and happy, and after all, children grow fast! Sometimes though you may get comments from other kids or relatives, or hear people talking about ‘puppy fat’ or ‘filling out’.
Nowadays there are more and more children with obesity. This is why it can be difficult to tell just by comparing yourself to your friends and classmates. So, what’s the sure-fire way of finding out?
Most experts, doctors and dieticians agree that the Body Mass Index is the best way to find out if you are overweight.