Once we reach the age of 20 our body is essentially fully grown and so we can use the standard measure of BMI (Body Mass Index) to determine whether or not we are overweight or obese.
However, during childhood, adolescence and our teenage years we develop at varying rates often gaining height very slowly for a period of time and then putting on a spurt of growth.
We also tend to develop excess fat at certain stages of our development, which often gives rise to the term ‘puppy’ fat.
For this reason, although we can still use BMI as a measure of child obesity, the interpretation of the results of our BMI calculation becomes somewhat tricky.
In this case we have to turn to a series of specially developed charts which have been formulated separately for both boys and girls and which look at weight data for a wide range of children at different ages. As you will see from the example chart shown here, which is provided courtesy of the CDC, reading the result is not a simple matter for the lay person.
Interpreting BMI results for children is not something which most parents should attempt for themselves and this is best left to your doctor. This said however parents can certainly keep an eye on a child’s BMI and there is an excellent online children’s BMI calculator available from the CDC which will not only make the calculation for you, but will also provide you with an initial interpretation of the results and advise you about whether or not you should consider consulting your doctor. The CDC child BMI calculator can be found by clicking here.
It is essentially the fact that the amount of body fat changes with age during a child’s development, and that this amount varies between boys and girls, that makes it impossible to simply draw up a standard BMI chart for children.
By the same token, healthy weight ranges also vary with age and gender and alter as height increases.
These facts are of course well understood by the medical profession and, with this knowledge, it is fairly simple to assess whether or not a child is within the correct weight range for his or her stage of development. But how do we as parents make this assessment without medical knowledge or the ‘tools of the trade’?
The simple answer is that we have to use our own judgment and check this from time to time with our family physician. Even if your child is seemingly fit and well and never seems to have a day of illness, he or she should have regular checkups at least one a year and these should include basic developmental checks including a check of your child’s weight for his or her age.
On very important thing to remember too is that habits formed in childhood often stay with us for life and can be extremely difficult, if not almost impossible, to break in later life. For all too many children today obesity, which used to be very much something which was seen in later life, is now appearing at younger and younger ages and it is not at all uncommon today to find even teenagers having to resort to gastric bypass surgery to cure a problem which, in most cases, need never have arisen in the first place. As parents we all have a responsibility to ensure that our children get the very best possible start in life and that includes teaching them to eat a good and balanced diet, take regular exercise and keep an eye on their weight.