• Changing lifestyle and dietary patterns have contributed to increasing obesity rates in children.
  • Lifestyle and diet changes can help children to maintain a healthy weight.
  • Obesity can result in serious health problems in childhood and later life.
  • Children who are obese tend to become obese adults.
The number of overweight children in Australia has doubled in recent years, with a quarter of children considered overweight or obese. Causes of obesity in children include unhealthy food choices, lack of physical activity and family eating habits.

This rise in the number of overweight children is disturbing, because it causes health problems and can lead to social problems. Overweight children are more likely to be teased by their peers or to develop low self-esteem or body image problems. Once children are overweight, it requires a lot of effort and commitment for them to return to a healthy weight.

Overweight and obesity in children are among the most important risks to children’s long and short-term health. Overweight children are very likely to become overweight adults.

Risk factors for childhood obesity

Your body stores unused energy (kilojoules) as body fat. To maintain a healthy weight, you need to use (or ‘burn’) the energy from the foods you eat. If you eat more than you use, your body will store the extra energy as fat.

Factors that may cause children to become overweight and obese include:
  • Food choices – these include choosing high fat and sugary foods instead of healthier options.
  • Lack of physical activity – Australian children are less active than they were in the past.
  • Spending a lot of time on sedentary pursuits – Australian children watch, on average, around 2½ hours of television a day, as well as spending time using computers and other electronic games. It seems that these pastimes are replacing active ones.
  • Overweight parents – a family’s eating patterns can have a major influence on whether a child maintains a healthy weight. Some overweight parents may be less concerned about their children also being overweight than parents who have a healthy weight.
  • Genetics – some rare gene disorders cause severe childhood obesity. In many other people, particular genes acting together probably make some children more susceptible to obesity. If there is a family tendency to become overweight, parents need to be even more aware of making healthy food choices for the whole family.

Childhood obesity is a worldwide problem

Levels of childhood obesity are increasing at alarming rates in many countries, including the United States, the United Kingdom and Australia. In Australia, one in five children and adolescents are either overweight or obese.

From 1985 to 1995 the number of overweight 7–15 year olds almost doubled. The numbers of obese children has more than tripled. At the current rate, it is predicted that 65 per cent of young Australians will be overweight or obese by 2020.

Society has contributed to obesity

As overweight and obesity have become more common, there have been some major changes in how we live. These changes have led to people either eating more or becoming less active, all of which has contributed to an increase in overweight and obesity. For example:
  • The overall cost of food has gone down.
  • More food is prepared away from home.
  • Energy-dense foods and drinks are more readily available.
  • Portion sizes have increased.
  • Marketing of energy-dense foods and drinks has increased.
  • The use of cars has increased.
  • The number of two-income families has increased.
  • The time spent in paid employment has increased.
  • The role of physical education in the school curriculum has reduced.

Health problems associated with obesity

Most of the health problems associated with obesity will become obvious in adulthood. Early signs of these later problems are commonly found in children.

Potential health problems for obese children include:
  • type 2 diabetes – while this condition is most commonly seen in adults, it is now also being diagnosed in children
  • eating disorders such as bulimia or binge eating
  • orthopaedic disorders – problems with foot structure
  • liver problems, including fatty liver
  • respiratory disorders, such as blocked airways and restrictions in the chest wall, which cause breathlessness during exercise
  • sleep apnoea – this is a condition that causes difficulty breathing when sleeping. It also causes snoring, waking often and poor sleep. It makes people feel tired and contributes to poor concentration during the day
  • cardiomyopathy – a problem with the heart muscle, caused when extra effort is needed to pump blood.

Obesity in childhood leads to obesity in adulthood

Overweight or obese children are more likely to remain obese as adolescents and become overweight or obese adults. About 80 per cent of obese adolescents will become obese adults.

Social problems for obese children and adolescents

Obesity can have a major impact on how children feel about themselves and how they interact with others. Obese adolescents are more likely to have low self-esteem, which may impact on other aspects of their lives, such as the development of friendships and competency at school.

Being obese as a child or adolescent increases the risk of a range of diseases and disorders in adulthood, regardless of whether the adult is obese or not. It’s important to identify and start to reverse the condition before children become adults. Ideally, overweight and obesity should be prevented.

Where to get help

  • Dietitians Association of Australia Tel. 1800 812 942
  • Your doctor

Things to remember

  • Changing lifestyle and dietary patterns have contributed to increasing obesity rates in children.
  • Lifestyle and diet changes can help children to maintain a healthy weight.
  • Obesity can result in serious health problems in childhood and later life.
  • Children who are obese tend to become obese adults.
  • Batch, J. & Baur, L., ‘Management and prevention of obesity and its complications in children and adolescents’, in Medical Journal of Australia, 2005, vol. 183, no. 3, pp. 130–134. More information here.
  • Obesity and overweight [online], World Health Organization. More information here.
  • ‘Other diet-related risk factors and physical inactivity’ [online], in The World Health Report 2002: Reducing risks, promoting healthy life, Chapter 4, World Health Organization. More information here.
  • About overweight and obesity [online], Population Health, Department of Health and Ageing, Australian Government. More information here.

More information

Children (4-12)

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This page has been produced in consultation with and approved by: Royal Children's Hospital - Nutrition Department

Last updated: April 2013

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