Weight, exercise and eating disorders

for children and young people

This information looks at some of the reasons why people worry about their weight, and provides information and support on eating disorders. It is aimed at young people, their parents and carers, and schools.


This is information, not advice. Please read our disclaimer.

Most of us, at some time in our lives, feel unhappy about the way we look. Feeling like our bodies look different than those of our friends or siblings can make us feel anxious and less confident. Some of us might try to make changes to our appearance through clothes, makeup, exercising or dieting.

Many of our thoughts about what looks good are strongly influenced by social media, fashion and trends, and the opinions of our friends. While most of us know that the pictures we see on social media or in advertising have been photoshopped and that the models and influencers we see are not ‘realistic’ representations of real bodies, it can still be hard not to compare yourself and develop negative feelings about your body image and physical appearance.

It’s important to remember that your weight, height and appearance all depend a lot on your genes, and that there is no one way that everyone is supposed to look.

This will depend on lots of different things, such as your age, sex, height and how much exercise you do. The most important thing to do to maintain a healthy weight is to have a healthy diet and to stay active.

Our bodies need a healthy, balanced diet to ensure they grow, develop and function normally and that we have enough energy to do all the activities we enjoy. A balanced diet incorporates fruit, vegetables, carbohydrates, proteins, dairy (or non-dairy alternatives) and fats to provide all the things our bodies need to function.

Here are some suggestions for how to eat healthily. You can find out more in the further information section at the end of this resource:

  • Eat regularly – Aim to eat breakfast, lunch and an evening meal, and one or two snacks in between meals if you get hungry.  Eating regularly can help you to manage your appetite and energy levels.
  • Aim for balance – When choosing your meals, consider the foods on your plate and try to follow guidelines where possible. You might not be able to include them in every meal, but try to make sure that what you’re eating includes all the food groups. For example, for dinner you might have rice (carbohydrate) with chicken (protein) and carrots (vegetable) followed by fruit and yoghurt (dairy). You can find out more about food group guidelines at the end of this leaflet.
  • Fruit and vegetables – Try to work towards eating several portions of fruit and vegetables each day (at least five portions is recommended). These are a good source of vitamins, minerals and fibre. These can be fresh, frozen, tinned, dried or juiced.
  • Carbohydrates – These should make up around a third of the food you eat. Carbohydrates include rice, potatoes, bread, pasta and cereals, and are a good source of energy, nutrients and fibre. Choose higher fibre wholegrain varieties, such as wholewheat pasta and brown rice, or simply leave skins on potatoes.
  • Dairy and non-dairy alternatives – These are a good source of protein and calcium, and should be included regularly in your diet. Non-dairy alternatives include things like oat milk or soya yoghurt. You should make sure they have added calcium to protect your bones.
  • Meat, fish and non-animal alternatives – These are excellent sources of protein and minerals. Aim to have fish twice a week, and one should be an oily fish such as salmon or mackerel. If you don’t eat fish, meat or dairy, you should try to find foods that have added vitamin B12 in them, as this is not usually present in plant-based food. Non-animal alternatives include things like tofu, Quorn or seitan.
  • Fats – Unsaturated fats such as vegetable, sunflower, olive and rapeseed oils or spreads help keep our hearts healthy and should be included in your diet.

An active lifestyle contributes to maintaining a healthy weight. It’s important to make physical activity a part of your daily routine.

Children and young people under 19 should aim to do two types of physical activity each week according to the NHS. These should be an exercise that raises your heart rate (aerobic exercises, such as swimming, running or dancing) and an exercise that strengthens your muscles and bones (such as gymnastics or martial arts). Any exercise and activity you do can help to contribute to good health, so choose something you think you will enjoy.

If you have been diagnosed with an eating disorder, this guidance may not apply. Please discuss this with your doctor. It is ok to take time away from physical activity to promote your recovery from an eating disorder.

Try to use reliable sources, like the NHS website, to find information about health and diet. Magazines and websites often run stories relating to weight, health or wellness and you might see social media influencers promoting weight loss products or diets. A lot of this information isn’t based on good quality research.

Restrictive diets or exclusion diets, where you avoid certain foods or dramatically reduce how much food you eat, don’t help people to lose weight in the medium or long term. They can make you put on weight over time, can be dangerous to your health and can even lead to disordered eating and depression.

Some people find that they eat differently when they are experiencing problems at school, with friends, or at home. Your appetite can be affected by things such as not sleeping enough, stress, pressure, worry or tiredness.

Some people eat more when they are dealing with stress or worry, and put on weight, while other people eat less than usual and end up losing weight.

If you are unhappy or stressed, it can be easy to focus on your weight and eating habits instead of the things that are bothering you. If you have noticed that you are eating more or less because of how you are feeling, speak to someone you trust and let them know so that they can support you.

If you have changed the ways you eat to help cope with your feelings, and feel as though it is having an impact on your life, you might have developed an eating disorder.

An eating disorder is a mental health condition where someone develops unhealthy eating behaviours and ends up eating too much or too little, or worrying about their weight or the way their body looks. Most people living with eating disorders are not underweight.

Eating disorder diagnoses can include the following:

  • Anorexia nervosa.
  • Bulimia nervosa.
  • Binge eating disorder
  • Avoidant/restrictive food intake disorder (ARFID)
  • Other specified feeding and eating disorder (OSFED) – you can find out more about OSFED and the eating disorders it covers.
Anorexia nervosa and bulimia nervosa are more common among girls but also happen in boys.

Anorexia nervosa is an eating disorder where someone will try to lose weight by eating as little as possible. Someone with anorexia might also exercise a lot, make themselves sick or take medications that help them lose weight like laxatives.

Below are some of the signs that you or someone you know might have anorexia. Remember, you won’t necessarily experience all these signs. If you are having any of these feelings or changes in your health, speak to someone you trust and ask for help:

Changes to your eating and behaviour

  • you are very worried or spend a lot of time worrying about your weight and shape
  • believing you are overweight when you are a healthy weight or underweight
  • missing meals, eating very little or avoiding certain food groups
  • you have made sudden, major changes to your diet, and this is worrying you or the people around you
  • you are avoiding social situations that involve food like going to restaurants or family mealtimes
  • you have strict habits around your food, such as recording what you eat or weighing yourself regularly
  • you are exercising a lot more than usual to lose weight
  • you are making yourself sick
  • you are taking medicine to make you poo (laxatives) or make you wee (diuretics) or taking medicine to reduce your hunger (appetite suppressants)
  • your mood has changed, and you feel sad, irritable or anxious.

Changes to your body

  • you are losing weight quickly
  • your weight and height are lower than expected for your age
  • you feel cold, get dizzy or have cold hands and feet
  • if you have periods these might stop or become irregular (this won’t happen if you are taking contraception that regulates your periods).

It is important to remember that you do not have to be very underweight to have anorexia. You should still get help no matter what your weight is if you experience any of these changes to your eating, behaviour or body.

Here are some of the things you might notice if someone you know has anorexia:

  • they are more active than usual and do a lot of exercise
  • they say they are fine even when they seem to have lost weight
  • they avoid undressing in front of others or looking at themselves in the mirror
  • they wear loose clothes to hide their size.

Bulimia nervosa is an eating disorder where someone takes part in binge eating and extreme weight-control behaviours. For example, eating a large amount of food very quickly and then vomiting or using laxatives to get rid of it.

If you have bulimia, you might:

  • eat very large quantities of food very quickly (known as binging)
  • experience a feeling of a loss of control when you binge
  • take part in some kind of purging behaviour, e.g. vomiting or using laxatives to make yourself go to the toilet
  • worry excessively about your weight and shape
  • notice damage to your teeth from vomiting
  • notice changes to your weight, including weight loss or weight gain.

Some people have the symptoms of anorexia and bulimia at the same time.

Bulimia can have a very negative impact on your physical and mental health, and you should seek help for it straight away.

Binge eating disorder shares some similarities with bulimia. People who have binge eating disorder will eat large amounts of food in a short period of time, and feel as though they have lost control when they do. They might eat in secret and eat even when they aren’t hungry or until they are uncomfortably full. Someone with binge eating disorder might eat more than they need to when they aren’t binging, or eat normally.

Unlike other eating disorders, someone with binge eating disorder won’t fast or use vomiting or laxatives to get rid of the food afterwards. Binge eating disorder can lead to weight gain for many people, though this isn’t the case for everyone.

Avoidant/restrictive food intake disorder (ARFID) is a type of eating disorder which causes a person to avoid or restrict their diet. Unlike anorexia nervosa, this is not due to concern about weight or shape. Some of the reasons people restrict their diet can include:

  • a fear of vomiting or choking
  • sensitivity to certain characteristics of food (smell, taste, appearance, texture etc.)
  • a lack of interest in eating.

However, for some people, the reasons for restricting their diet are not clear.

By avoiding or restricting their diet, someone with ARFID will not be able to meet their energy or nutritional requirements. This can result in weight loss, nutritional deficiencies, and dependence on either oral nutritional supplements or tube feeding, and physical health problems. Restricting or avoiding food can also cause difficulties in school, family or social life.

Eating disorders can have a very negative impact on your physical and mental health. As well as causing you to gain or lose large amounts of weight, if you have an eating disorder it can affect many different parts of your body including your heart, stomach, liver, bones, muscles, skin and teeth.

Eating disorders can affect your emotional wellbeing and social life. This can result in being unable to enjoy and take part in activities that are normal for your age such as being with your friends or families, going to school or participating in activities.

It is also recognised that it is common for people with eating disorders to develop other mental health disorders such as depression, anxiety and obsessive-compulsive disorder.

When someone becomes very unwell with an eating disorder, they can need hospital treatment. Some people with eating disorders who are very unwell have died. However, eating disorders are treatable and there is lots of help available if you are struggling. Speak to someone you trust as soon as you can if you feel like you might have an eating disorder.

If you are worried about your weight or feel you might have an eating disorder, help is available to you. Speak to someone you trust, such as: 

  • a member of your family or your carer
  • a trusted friend
  • a teacher, school nurse or counsellor
  • a social worker, if you have one
  • your GP, doctor or any other health professional you are in contact with
  • the eating disorder charity Beat offers free, non-judgemental advice and support.

If you need more specialist help, you might be referred to a professional at your local child and adolescent mental health service (CAMHS) or community eating disorder team. These are teams of specialists including nurses, psychologist, dieticians and child and adolescent psychiatrists that can help you to understand why you are feeling the way you are, and help you to get better.

“I’m 14 now, but I think I started having a problem when I was 11. I got really worried about my weight and my body. I had put on a bit of weight and was pretty upset when some of the boys in my class started laughing and calling me fat in the changing rooms after rugby. I began to stay late at the pitch, to do more running.

“I noticed myself feeling really sad and guilty after meals, so I started to reduce the amount I was eating. I began looking at apps on my phone about fitness too. My parents noticed, as my appetite had always been good, but now I was arguing with them if they offered me certain foods.

“Everyone started telling me I was losing weight, but I still felt fat every time I saw myself in the mirror. I gradually stopped going to rugby; it was like it just didn’t matter to me anymore.

“I guess it didn’t help that my parents were arguing a lot at the time. I overheard them a few times arguing about me too. It felt like everything that was good was falling apart and losing weight was the only thing that I could focus on.

“My parents took me to see my GP, who told me I was underweight, and my blood pressure was worryingly low. They arranged for me to see a specialist young people’s mental health team who began to offer me regular appointments and did blood tests and heart monitoring. They also recommended that my parents should start to talk to the team to think about how I could get better.

“That’s when things slowly started to get a bit easier. For the first time in ages it felt like we were all properly listening to each other. Gradually I started to eat some of the foods that I had been avoiding. I put on some weight and spent less time feeling worried about exercising. After a few months of hard work, the team discharged me.

“I can still sometimes feel a bit anxious about getting changed, but mostly it doesn’t bother me. I still watch rugby, but I don’t play anymore. I prefer cricket now!”

Information on healthy eating and exercise

Information on eating disorders

  • NHS, eating disorders – Information from the NHS on what eating disorders are and how to get help.
  • Beat – The eating disorder charity Beat provides helplines, online support and a network of UK-wide self-help groups to help adults and young people in the UK with eating disorders. Tel: 0808 801 0432
  • Beat, contact information - On this page you can find all the different ways of contacting the eating disorder charity Beat through their helplines and email
  • Young Minds – This UK charity offers information to young people about mental health and emotional well-being, as well as support to parents and carers.

Further reading

  • Getting Better Bite by Bite: A Survival Kit for Sufferers of Bulimia Nervosa and Binge Eating Disorders by Ulrike Schmidt. Routledge, 2015
  • Caring for a Loved One with an Eating Disorder: The New Maudsley Skills-Based Training Manual by Gillian Todd, Janet Treasure, and Jenny Langley. Routledge, 2018
  • NICE Guidance (2017) Eating disorders: recognition and treatment, information for the public

Revised by the Royal College of Psychiatrists’ Child and Family Public Engagement Editorial Board (CAFPEB) and the National Collaborating Centre for Mental Health.

Special thanks to the eating disorder charity Beat, who reviewed this resource.

This resource reflects the best possible evidence at the time of writing.

Full references for this resource are available on request.

Published: Aug 2022

Review due: Aug 2025

© Royal College of Psychiatrists