Body Mass Index and Childhood Obesity

Thanks to the modern day unhealthy lifestyles and love for junk food, the obesity levels among children has risen to dangerous levels. As a parent, the last thing you want for your children is them to be among the affected demographic. Besides watching what your children eat and making sure that they are active enough to shed some weight, you need to be weary of their BMI because it is the best indication of the child’s weight. A lot of parents have heard about the term BMI but very few understand its significance or how to apply it to determine your child’s weight state. We therefore want to explore the significance of BMI in children and how to tell if your child is overweight or underweight. So, what is BMI?


The Body Mass Index is a person’s weight in kilograms divided by the square of the person’s height in meters. It is used to indicate whether an individual is overweight or underweight by taking into consideration their height and weight. For children and teens the BMI is normally age and sex specific. This means that the BMI for a healthy child varies according to age and sex. In children therefore, one can have a high BMI for their age or sex but still be deemed perfectly healthy.

Contrary to BMI in adults, BMI among children and adults is interpreted differently even though it is calculated by dividing weight with the square of the height. This therefore means that it is not a diagnostic tool per se but just part of the indicator. Unlike in adults where a very large BMI means that one is overweight and possibly obese, a high BMI in children and teens needs to be expressed relative to other children of the same sex and age to ascertain whether the child or teen is overweight, underweight or just in the normal weight range. This is due to the rapid changes in weight and height with age and sex. So, when is a child considered to be obese using the child’s BMI?

Childhood obesity and BMI

In children, obesity is defined as a BMI above the 95th percentile for children and teens of the same age and sex. These percentiles are provided by the Center for Disease Control and Prevention and these statistics were collected from 1963-1994. When we say that your child’s BMI is above the 95th percentile for children and teens of the same age and sex, we mean that he has a BMI greater than the BMI of 95% of all the children of the same age and sex. This is different from adults because the BMI of indicates the exact weight state of the individual irrespective of their age or sex. That means that if the BMI is above the regular range, the adult is deemed to be overweight or underweight depending on whether the BMI is above or below the BMI range respectively.

To tell if your child is obese therefore, it will take more than just BMI. There is need for further assessment by a qualified and trained medical practitioner to ascertain whether you child is overweight. BMI on its own can’t be used as a diagnostic tool in young children and teens. Some Body Mass Indexes should straight away raise eyebrows though. If for example your child of 12 years has a BMI>30Kg/m2, then there is a very high likelihood that the child is obese. Equally if your child of 10 years has an index<10Kg/m2 then he/she is underweight.

Consequences of obesity during childhood

What are the health risks of a child being overweight or underweight? Here are some of the most common health risks and consequences of childhood obesity;

High blood pressure and high cholesterol levels in the body. These are increase the likelihood of the child suffering from cardiovascular diseases which are very dangerous.

Increased risk of contracting type 2 diabetes. High cholesterol levels and obesity are associated with type 2 diabetes

Difficulties with movement and mobility due to joint complications and musculoskeletal discomfort.

Liver diseases, kidney stones and gastro-esophageal reflux which is popularly referred to as a heartburn.

Reduced self-esteem and psychological stress caused by lack of self-confidence and constant attack from classmates.

Parental measures to reduce chances of childhood obesity

To reduce the chances of your children becoming obese, you will need to do the following;

Educate them on the importance of eating healthy foods and avoiding junk foods because they are the chief suspects when it comes to obesity. Always give them organic foods and make it habitual for them to eat fruits. This will go a long away in helping them remain healthy.

Educate them on the significance of remaining physically active and taking part in other activities in school. Play with them at times and just make sure that they are not always indoors watching television or playing video games.

Take them to your doctor for regular checkups to determine their BMI and get further tests to ascertain their weight status. The general doctor will also offer professional advice on how to remain healthy which will be very helpful.