GROWTH CHARTS FOR CHILDREN
The easiest way to measure a young child’s growth is by plotting their weight and height over a period of time on growth reference charts. Babies and young children who receive good nutrition and are not sick for long periods will have healthy growth and development patterns.
Many things influence growth including genes, nutrition, good health and sickness. Babies and young children do not usually grow in a perfectly smooth way. They usually grow in ‘bursts’. A change in height and weight can occur in a short amount of time.
For babies, the first year of life is a time when they grow very rapidly. On average, a newborn baby will more than triple its birth weight by their first birthday. Growth slows down in the second year with, on average, two to three kilos added each year until the next major growth ‘spurt’ at puberty.
How growth is measured
Doctors, nurses and other health professionals use a variety of ways to assess growth in children. The most common ways include:
Basic body measurements including weight, height (length) and head circumference for male and female children from birth to three years of age
Standards called growth references or growth charts are used to help interpret these measurements
Calculation of BMI (body mass index) and child-specific BMI charts for children over 2 years.
Body mass index (BMI) for children
The BMI is one way to assess whether a child is underweight, healthy weight or overweight. The BMI is a single number that interprets a child’s weight in relation to their height. It is calculated by dividing the child’s weight in kilos by their height in metres squared.
BMI =Weight (kg) / Height (m2)
If a BMI calculation is used for a child (or for an adolescent), it must be compared against age and gender centile charts. This is because, as children grow, their amount of body fat changes and so will their BMI. For example, BMI usually goes down during the toddler/preschool years and then increases during the school years and into adulthood.
For children over the age of two, BMI percentile charts can be used to assess weight and obesity. The charts use centile cut-offs as a guide only. BMI above the 85th centile and below the 95th centile suggests the child is overweight. The 95th centile and above indicates obesity.
Things to remember
Most babies and young children will grow and develop normally if they receive good nutrition and are not sick for a long time.
Growth charts for children, including the BMI centile charts, are intended only as guides.
Always see your doctor if you are concerned about your child’s growth.