Obesity | Better Health Channel

A child or adolescent who is living with obesity has more body fat than other children of the same age. It's healthiest for your child to stay within a certain weight range for their height and age as they grow. This is known as 'BMI-for-age'.
A BMI-for-age score between the 85th and 95th percentile could mean your child's body weight is outside a healthy range. This is known as living with overweight.
A BMI-for-age score at the 95th percentile or higher could mean your child's body weight is outside a healthy weight range. This is known as living with obesity.
In Australia, around 1 in 4 children aged between 4 and 15 years live with overweight or obesity. Living with overweight or obesity can significantly affect a child's physical health, mental health and wellbeing. They are also more likely to live with overweight or obesity during adulthood.
The most visible sign of obesity is excess body fat. You may also notice your child is growing out of their clothes faster than other children. They may also look bigger than other children of the same age and height.
It is not always easy to tell if your child is living with overweight or obesity. You can use NSW Health's healthy weight calculator (Opens in new tab) to estimate your child's BMI-for-age for children aged over 2 years. Remember that most online BMI calculators are designed for people aged 18 years and over.
It's best to see your doctor to understand your child's BMI measurements as they grow.
Many things can cause your child to gain weight. For most children, obesity occurs if they gradually take in more energy (measured in kilojoules) from eating and drinking than the amount their bodies use to grow, play and exercise. Unused energy is turned into body fat. Over time, this may increase your child's body weight beyond what is considered healthy for their age.
Some other causes of overweight and obesity during childhood may be outside of their control, such as:
You should take your child to see a doctor if you:
Your doctor can assess your child's weight and advise on lifestyle changes or refer you to other health professionals such as a paediatrician, dietitian or psychologist.
Learn about how to get the most out of your doctor's appointment.
If your child is older than 2 years of age, their doctor can diagnose overweight or obesity using a BMI percentile chart (Opens in new tab). Your child's BMI is calculated and then charted across weight information for the population as a growth curve. This takes into consideration their sex, age, growth and maturation patterns.
BMI is calculated as the ratio of weight in kilograms divided by height in metres squared (kg/m2).
A healthy BMI for children and teenagers will vary according to their age:
The BMI classification has some limitations. It does not distinguish between the proportion of fat or fat-free-muscle. This makes it less accurate for some body types.
Children under 2 years are not diagnosed with overweight or obesity. From birth until 2 years, growth charts are used to help check that babies are growing well. You should not feel pressure to make sure your baby's weight is on or near the 50th percentile (average) for their age. All babies grow at different rates. They come in all shapes and sizes.
Read about baby growth charts (Opens in new tab).
Sometimes your doctor may want to measure your child's waist circumference. Your child's waist circumference can help estimate their risk of cardiovascular disease.
Your doctor can measure your child's waist circumference using a measuring tape around their stomach, roughly at the level of their belly button.
If your child is living with overweight or obesity, the aim of treatment is to help them achieve a healthy weight, rather than lose weight. In most cases, younger children should not aim to lose weight — rather they should 'grow into their weight'. This means that the goal is for them to gain height without gaining weight. Deliberate weight loss in children can affect their growth and development.
To help your child achieve a healthy weight, it's a good idea to consider:
It can help to get advice from a multidisciplinary team that includes:
Together, they can guide you in making the right changes to your child's diet and lifestyle to encourage them to reach a healthy weight.
Read more about the Australian Dietary Guidelines (Opens in new tab).
Read more about the Australian 24-hour movement guidelines for children and young people (5 to 17 years) (Opens in new tab).
Here are some suggestions to encourage your child to eat more healthily and achieve a healthy weight:
Kids who grow up with healthy eating habits are more likely to make healthy food and drink choices when they're older.
See more ideas on healthy eating habits to share with your child.
Physical activity is an important way to achieve and maintain a healthy weight. School-aged children should have at least 60 minutes of activity every day.
You can encourage your children to be active by doing physical activity together. Here are some ideas:
Limit screen-based activities (Opens in new tab) to a maximum of 2 hours a day for school-aged children, and less than 1 hour a day for preschoolers and toddlers.
The best way you can help your child achieve a healthy weight range for their age is to support them. Get the whole family involved. It will be easier for your child to make changes if everyone in the family is modelling healthy behaviours.
Be aware of the emotional impact living with obesity can have on your child.
How you talk to your child about obesity can affect their willingness to aim for a healthy weight.
Keep the focus of your conversation on maintaining a healthy lifestyle and good health. Here are some tips:
Left unchecked, obesity can cause physical, social and emotional health problems.
Weight-related complications include:
The longer your child has an unhealthy body weight for their age, the more likely it is that your child will live with obesity as an adult, which also carries health risks.
In addition to complications to your child's physical health, children living with overweight and obesity can sometimes experience teasing or bullying. This can affect their:
Read about young children and bullying.
There are many factors that contribute to overweight and obesity in children. Not all of them are preventable, but there are things you can do to help your family maintain a healthy weight:
For more information and support, try these resources:
The NSW Government has translated the Australian Guide to Healthy Eating (Opens in new tab) into many community languages.
The 'Tucker Talk Tips 4 Kids (Opens in new tab)' guide provides information for Aboriginal and Torres Strait Islander people about what foods to choose each day for a balanced and healthy diet.
Rethink Sugary Drink (Opens in new tab) has resources for Aboriginal and Torres Strait Islander people to help you cut out sugary drinks for you, your family and community.
Find out how we develop and review our content.
Last reviewed: September 2024










Worried about your health?
Select a symptom, answer some questions, get advice