Children and Body Measurements

Anthropometric body measurements (including weight, height and BMI) are commonly used to measure and track growth over time in children (infants, children, adolescents). Unlike adulthood, there are substantial periods of growth and development in childhood. As a result, it becomes even more important to not make judgments or decisions based on one measurement in time with children but rather consider measurements over a period of time (Dieticians of Canada and Canadian Paediatric Society, 2014). Keep in mind that health comes in all sizes and shapes (OSF Healthcare System, 2023).

Height, weight, BMI and other body measurements are considered in the context of growth charts which are percentile curves in reference or relative to children of the same age and sex (Dieticians of Canada and Canadian Paediatric Society, 2014). In this chapter, you are introduced to percentiles for children aged 2 to 19 years of age. In Canada, these are based on the World Health Organization.

Boys’ individual charts (based on sex assigned at birth):

• 2 to 19 years: boys – height-for-age and weight-for-age percentiles
• 2 to 19 years: boys – body mass index (BMI) for age percentiles

Girls’ individual charts (based on sex assigned at birth):

• 2 to 19 years: girls – height-for-age and weight-for-age percentiles
• 2 to 19 years: girls – body mass index (BMI) for age percentiles

Interpretations

See Table 2 for cut-off points for percentiles from the Dieticians of Canada and Canadian Paediatric Society (2014). Keep in mind that this table provides a simple understanding and in fact a full understanding of these cut-off points is much more complex. These are commonly used in primary care. When using these, additional training is suggested. Please see Dietitians of Canada for more information about training and additional interpretations.

In terms of how to read percentiles: an example is if a child’s BMI is 80th percentile, that means that the child’s BMI is more than 80% of children the same age and sex.

Table 2: Cut-off points

References

Dieticians of Canada and Canadian Paediatric Society (2014). A health professional’s guide for using the WHO growth charts for Canada. Childhood percentiles

OSF Healthcare System (2023). Taking the confusion out of reading a growth chart. https://www.osfhealthcare.org/blog/taking-the-confusion-out-of-reading-a-growth-chart/