Assessing BMI and Using Growth Charts

A healthy weight is defined by a body composition that positively contributes to an individual’s overall health, wellbeing and quality of life over their lifespan. Healthy weights in children vary by age, sex and height. It is also important to remember that weight is only one marker of health and a healthy weight is different for each individual child.

Body Mass Index (BMI) can be used to assess whether a child is overweight or obese. BMI is an indirect indicator of body fat but will be less helpful if the individual measured is very muscular. The BMI is based on height and weight that tells if a child or adult is in a healthy range compared to his or her peers. The Canadian Medical Association recommends that physicians calculate BMI in children 2 years and up. A BMI calculator is available on the Dietitians of Canada website.

A growth chart is used to correctly interpret a child’s BMI. After calculating a child’s BMI, the next step is to plot the child’s BMI on a growth chart. The Childhood Obesity Foundation recommends using the World Health Organization (WHO) Growth Charts adapted for Canada and posted on the Dietitians of Canada website. There are growth charts for boys and girls 2-19 years: BMI. Please click here to find these charts.

For children in the overweight or obese range, a childhood healthy weights program such as the ShapedownBC Program or MEND program may be of interest. Please click here for childhood healthy weights programs in Canada

Please note that Dietitians of Canada has also posted a health professional’s guide to using the new WHO growth charts. This guide outlines the ways to use and interpret the 2006 WHO Growth Standards and the WHO Growth References 2007 to assess physical growth in infants, children and adolescents. Please click here to access the guide.