According to the World Health Organization (WHO), measures must be taken immediately to counter the epidemic and its impact.
In Canada, the number of overweight children continues to grow. Between 1978 and 2004, the percentage of obese children and young Canadians between the ages of 2 and 17 years old has nearly tripled. In Quebec, it’s estimated that 18% of children between the ages of 2 and 17 years old are overweight and nearly 10% are obese.
This article will explain the definition of obesity in children, the consequences and causes, some tips and useful links on the subject.
What is childhood obesity
Obesity is generally defined by someone who weighs at least 20% more than their normal healthy weight, which is calculated by using the body mass index (weight/height). For children 0 to 36 months old however, the use of a growth chart will determine if the weight is excessive or too low.

Body mass index
The body mass index (BMI), as measured for adults, is not suitable for children and teenagers because the distribution of fat tissue is constantly changing during their growth and is not the same for boys and girls. An index was developed specifically for children, taking into accounts age and sex. By visiting the following link, you can calculate the BMI of your children between the ages of 2 and 19 years old.
Calculating your child’s body mass index allows you to identify if he is overweight or likely to become overweight. BMI results are interpreted according to specific charts
Chart for boys 2 to 20 years of age
Chart for girls 2 to 20 years of age
Low weight |
BMI for children < 5th percentile |
Likely to become overweight |
BMI for children between 85th percentile and 95th percentile |
Overweight |
BMI for children < 95th percentile |
If your child is at the 60th percentile, this result indicates that 60% of children of the same age and sex have a lower body mass index. In addition, BMI is not a perfect measure and should be used in conjunction with other measures such as the skin fold assessment, the level of physical activity, diet and blood pressure.
Consequences of obesity
A child who is overweight will not automatically be obese in adulthood. However, several studies suggest that after the age of 8, a link can indeed be observed between the child’s weight and his weight in adulthood.
Several health risks are associated with being overweight including:
- Hypertension
- Increase of triglycerides (fat in the blood), thus increasing the risk of cardiovascular disease
- Diabetes
- Joint problems (in the knees for example) that may limit physical activities
- Sleep apnea (for very obese children) that is resumed by a bad night’s sleep and tiredness all day, which can lead to problems at school by reducing the capacity of the child to remembers things and keep focused.
Some studies have shown a link between obesity and some forms of cancer;
In addition to these physical problems, obese children are often rejected by other children and are more likely to have low self-esteem.