Gone are the days when it was “adorable” to have fat children. With the rates of severe obesity in children having tripled over the last twenty-five years, it is not surprising that we have a need, more than ever, for appropriate weight guidelines for children. The concern about obesity in children has escalated because severe obesity in childhood increases the risks of children developing heart disease and diabetes. Additionally, obesity in childhood perpetuates the risks of developing weight-related diseases in later life as overweight children have a 70% risk of being overweight later in life. This risk increases to 80% if one or both parents are overweight.
It is not only the overweight and obese children that we should be concerned about. Although children may be underweight or be at risk of being underweight at various points during his (or her) growth, this may be considered normal if the child is growing, developing normally, has a healthy diet, and is active and energetic. However, it is important to be aware that a child who is underweight may have an underlying health problem that requires address. It may be a medical condition causing the child to be underweight or it may be an eating disorder.
How can you tell if your child is overweight, underweight or just right?
One of the best methods is to visit your child’s paediatrician. However, child-weight guidelines can also provide a helpful method for parents to monitor the weights of their growing children.
It is important to note that child-weight guidelines are not so relevant to children below two years of age where growth rates can fluctuate considerably. Many infants that appear “obese” and who are “off the weight charts” during infanthood often normalise their weights as they grow older. This is especially true for breastfed infants.
What are the child-weight guidelines for different ages and genders?
There are two:
- BMI-for-age growth charts
- Clinical growth charts
In general, a child is considered underweight if his (or her) weight or BMI falls under the 5th percentile. The child becomes at risk of being overweight if his (or her) weight or BMI falls into the 85th-94th percentile. The child is overweight once his (or her) weight or BMI lies in the 95th percentile or greater.
1. BMI-for-age growth charts
Just as adults can calculate their BMI (body mass index) to determine if they are overweight, underweight, normal or obese, the same can be determined for children. However, the BMI guidelines for adults do not apply to children whose body fatness fluctuates as they grow. The method for calculating BMI in children is the same as that for adults, but the results are interpreted according to the children’s BMI growth charts.
The BMI Formula
BMI = weight(kg) / [height(m) x height(m)]
You can determine which percentile your child’s BMI falls under by utilising the charts for BMI-for-age percentiles for children age 2 to 20 for boys and girls developed by the CDC (Centers for Disease Control and Prevention). Alternatively you can use a BMI-percentile-for-age calculator for children.
When calculating your child’s BMI, it is important to be aware that the limitations of BMI for adults also apply to children. Because the BMI doesn’t directly measure body fat, it is still possible for a child to be overweight without being obese. Children who are athletic and possess a high degree of muscle mass can appear to be overweight without being obese.
2. Clinical Growth Charts
These are commonly used by doctors and health professionals when assessing a child’s height and weight. Clinical growth charts help us determine which percentile a child falls into according to a chart that is appropriate for age and gender.
Although child-weight guidelines serve only as that – a guideline for determining if a child’s weight is normal, overweight or underweight – they do assist parents in determining if their children potentially have a weight problem and possibly health-related risks or conditions. As with all guidelines, they are intended for use as a guide and it is recommended that you obtain a professional medical assessment if you suspect that your child may have weight-related problems.