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Obesity in children


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.

About childhood obesity

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.

Complications of obesity in children

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:

  • high blood pressure
  • high cholesterol levels
  • cardiovascular diseases such as heart disease and stroke
  • type 2 diabetes
  • osteoarthritis
  • some cancers, including endometrial, breast and bowel cancer
  • asthma
  • liver disease
  • sleep apnoea

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.

Causes of obesity in children

There are a number of different things that can cause obesity in children. Possible causes include:

  • eating a poor diet, for example, too many high-fat and sugary foods
  • inactivity, for example, not doing enough exercise and spending too much time watching television or in front of a computer
  • genetic (inherited) conditions, although these are rare

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.

Diagnosis of obesity in children

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.

Treatment of obesity in children

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.

  • Setting goals and giving rewards and praise. You and your child should be aiming to make long-term changes to the foods you eat and the activities you do. This is so that your child will be able to manage his or her weight when they become an adult. However, choosing some smaller goals to begin with may help you to focus and succeed. Give your child praise and rewards for their success, but make sure these aren’t food-related. Instead, try rewarding them by doing an activity they enjoy.
  • Get active. Children over the age of five need to do at least 60 minutes of moderate to vigorous intensity physical activity every day. This can be one session of activity or a number of sessions of 10 minutes or more. Activities should also include exercises that strengthen their muscles and bones, such as climbing or any activity that means children are lifting their own body weight. Try building activity into everyday life, such as walking or cycling to school or playing with other children. Do activities together as a family, for example, going to the park and playing football. Help your child to choose more structured activities that they enjoy, for example, dancing or swimming.
  • Cut down on inactive pastimes. Reduce the amount of time your child spends watching television or using a computer. Try to limit this to less than two hours a day or 14 hours a week.
  • Eat healthily. Your doctor or dietitian may ask you to keep a record of the food and drink that you and your child have. Based on what your child is eating, what he or she likes and dislikes and how old your child is, your doctor or dietitian may create a healthy eating plan. This can be made up of healthy foods which balance the energy each day that your child is using in their day-to-day activities. This is likely to mean cutting down on foods that have a lot of sugar or fat in them, and eating more fruit and vegetables and low-fat foods.
  • Involve the whole family. It’s important to get everyone to eat healthily and become more active so that your child doesn’t feel that they have been singled out. If you’re overweight, you should lose weight with your child. Look at how you eat as a family, try and sit down together for meals and set a good example with the foods you eat and the activities you do.


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.

Prevention of obesity in children

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.

  • Include starchy foods in meals such as potatoes, bread, rice and pasta, choosing wholegrain varieties where possible.
  • Eat plenty of fibre-rich foods, such as oats, beans, grains, fruit and vegetables, wholegrain bread, and brown rice and pasta.
  • Eat at least five portions of a variety of fruit and vegetables each day.
  • Eat a low-fat diet and don’t increase your fat and/or calorie intake.
  • Eat as little as possible of fried foods, sweets which are high in added sugars and fat, and high-fat foods such as takeaway meals or fast food.
  • Reduce the amount of sugary drinks you have, including fruit juices with added sugar, and drink more water.
  • Watch the portion size of meals and snacks, and how often you’re eating.
  • Eat regular meals, including breakfast, in a pleasant, sociable environment without distractions.
  • You should eat with your child and make sure that everyone is eating the same food.
  • Make enjoyable activities – walking, cycling, swimming and gardening – part of everyday life.
  • Minimise sedentary activities, such as sitting for long periods of time watching television, at a computer or playing video games.
  • Encourage active play, for example, dancing and skipping.
  • Be more active as a family, for example, walking and cycling to school and the shops, going to the park or swimming.
  • Encourage your child to participate in sports or other active recreation, and make the most of opportunities for exercise at school.

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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