Your child's weight

Weight loss in the first 2 weeks

It is normal for babies to lose some weight in the first 2 weeks after birth. Most babies are back at their birth weight by 2 weeks of age.

After this, steady weight gain is a sign that your baby is healthy and feeding well.

Your public health nurse and GP will help you if your baby has not regained their birth weight by 2 weeks or is losing weight. They may look for signs of medical problems.

If you are breastfeeding, your public health nurse will talk to you about how feeding is going and may ask to observe when you are giving a feed.

Checking your child’s weight

After the first 2 weeks, your child will be weighed by:

  • your GP at the 6-week check 
  • your public health nurse at each developmental check 

Many public health nurses also run ‘well baby’ clinics where you can bring your baby to be weighed.

Healthy weight gain

Most children are about three times their birth weight by one year of age – but this is just an average measurement. Your child may gain weight slower or faster than usual.

Sometimes weight gain can be slow if your child was premature or if they have been sick and off their feeds.

On average, a child gains 2kg to 3kgs (4.5lbs to 6.5lbs) each year until they reach puberty. Your child may gain weight slower or faster than this.

BMI (body mass index)

If your child is over the age of 2, your GP or public health nurse may record their body mass index (BMI). The BMI reading compares your child’s weight to their height. BMI can be a better indicator of possible weight issues than just weight alone.

If you are worried about your child’s weight, you can ask for a BMI measurement to be done.

Physical activity

Children under 5 should have at least 3 hours of physical activity spread throughout the day. This can be anything that gets them moving. Examples include crawling, walking, moving around the home, dancing, playing outside or exploring.

Page last reviewed: 4 December 2018
Next review due: 4 December 2021