Children who carry a lot of excess weight and have too much fat in their body are classed as being obese. It’s mainly caused by regularly consuming more energy (calories) from food and drink than their body uses and not doing enough physical activity.
Obesity means children are more likely to develop serious health problems.
Children need a healthy, balanced diet that gives them enough energy to grow and develop. This means that children usually need to take in more energy than they use and this extra energy forms new tissues as they grow. However, if children regularly take in too much energy, this is stored as fat and they will put on excess weight.
According to the World Health Organization, in 2010, there were around 40 million children under the age of five who were overweight worldwide. In the same year, three out of 10 children aged two to 15 were obese in the UK alone.
If your child is overweight or obese, he or she is more likely to develop serious health problems in the future. Sometimes, early damage can be done and may develop while he or she is still a child, such as development problems in their feet.
When your child gets older, or becomes an adult, he or she is more likely to develop health problems if they are obese. These include:
Obesity can also affect your child’s emotional and mental health. He or she may have low confidence or self-esteem, which may lead to depression. Being obese can also lead to eating disorders, such as bulimia.
There are a number of different things that can cause obesity in children. Possible causes include:
Some studies have shown that lifestyle factors during pregnancy and early motherhood may affect your child’s weight, such as smoking and breastfeeding. For more information, see our frequently asked questions.
If you’re obese, then your children are more likely to be obese. This may happen because you share the same eating or activity habits, or a combination of both.
For adults, a measurement called body mass index (BMI) is often used to work out whether you’re a healthy weight for your height. However, because children are growing, their height, weight and body fat can change a lot. BMI measurements are also very different between boys and girls. This means that the standard BMI can’t be used as a measure for children.
Special charts, called BMI centile charts, have been developed to show whether children are under or overweight for their age. These charts compare a child’s BMI against other children of the same sex and age. Your GP or nurse will use these charts to assess your child.
Your GP will also check to see whether your child has other health conditions related to being overweight. Your GP may also ask you and your child about the foods you eat and how active you are.
There are a number of different treatments for obesity in children. However, no treatment will work on its own. You will need to make changes to the foods you and your child eat and the activities you do, as well as changing some of the behaviours of the whole family.
Depending on the age of your child, your GP may plan to help your child to lose weight. However, weight loss is not always recommended in children so he or she may advise that you help to maintain your child’s weight. Therefore, as your child grows taller, his or her BMI improves but their weight stays the same. Your GP may refer your child to a paediatric dietitian (a specialist in children’s nutrition and health).
It’s important to make changes that the whole family can do, rather than asking your child to have a separate diet or to start ‘dieting’. This may mean changes to mealtimes and snacking habits, or starting activities that the whole family can do together. Lifestyle changes work best for your child when they are long term, permanent changes.
Some lifestyle and behaviour changes are listed below.
A medicine called orlistat can sometimes be used to help older children lose weight. However, it’s used very rarely and is only usually prescribed in a specialist clinic. Orlistat should only to be given to your child if he or she is over the age of 12, is very obese and has other health problems caused by their weight.
Weight-loss surgery for children is rare. Surgery will only be suggested if other treatments have failed, if your child has been through puberty or if he or she is very obese and they have other health problems.
Your doctor will discuss your child’s treatment choices with you.
Obesity in children is caused by many different things, some of which are difficult to change. For example, there is a greater choice of food available in our shops, and computers and television play a bigger part in many people’s lives than they did in the past. However, you can make a difference to the food your child eats every day and how active they are.
The National Institute for Health and Clinical Excellence (NICE) recommends the following.
Never put your child on a weight-loss diet without getting advice, as this can affect his or her growth. Talk to your GP or a dietitian if you have any concerns about your child's weight.
Produced by Natalie Heaton, Bupa Health Information Team, January 2013.
For answers to frequently asked questions on this topic, see FAQs.
For sources and links to further information, see Resources.
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This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the About our Health Information page.

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