on Eating Disorders


In order to treat eating disorders, you do not need to know the cause. However, it is understandable that you may want to find one.
It is said that there is no single cause for eating disorders. Eating disorders are complex, therefore there is rarely a simple solution.

However, some people are more at risk or “predisposed” to developing an eating disorder through genetics, biological factors and personality traits.
A person who is more predisposed to developing a certain disorder may then experience a difficult situation, event, change or trigger known as  “precipitating” factor and/or may have “perpetuating” factors that maintain the eating disorder. Perpetuating factors can include the short term powerful sense of achievement that a young person feels when they restrict or meet targets, or the emotional release that people can experience after vomiting.

It is not the parents, family members or young person’s fault that an eating disorder has developed.

The following section will discuss recent research which points towards potential risk factors for a young person developing an eating disorder.

Neurobiology and Behavioural Neuroscience

Some researchers believe that the brain could be the key to understanding why people develop eating disorders, and see eating disorders as a biological brain disease. Some parents have stated that it is useful to think of an eating disorder in this way as it has helped them to see eating disorder symptoms as part of the disease rather than “bad” behaviour.

Brain Based Facts:

  • A starved state can increase obsessive and specific eating disorder traits which is one of the many reasons why getting back to normal eating is important.
  • The brain shrinks when starved (reducing functioning)
  • The brain is still developing in adolescence right up until mid 20s.
  • Neurotransmitters (dopamine and serotonin) may play a role in eating disorders
  • Anxiety and obsessive symptoms may predate the eating disorder (potential risk factors for the development of eating disorders)
  • Food and nutrition may impact on neurotransmitters (Serotonin) and this may result in binge eating.
  • Restrictive eating may help “dampen” anxiety symptoms initially – this is why people may fall into the trap of an eating disorder as it provides some level of comfort.
  • People with anorexia may experience taste and rewards differently.

Others believe that neurons play a role in eating disorders. Neurons use neurotransmitters (chemical messengers) to signal to one another. Dopamine and serotonin are thought to be important neurotransmitters in eating disorders.  Serotonin is involved in memory, sleep, mood, and learning. Dopamine is thought of as a “pleasure” chemical as it is involved in the way people experience rewards.

Some researchers(1)(2)have found, through brain scans, that people currently suffering from anorexia have lower levels of serotonin than people without an eating disorder.

This was possibly due to the starved state of the individuals with anorexia.  When researchers looked at individuals who had been recovered from anorexia for a period of time, they found them to have higher levels of serotonin compared to those who had never had an eating disorder.  It is thought that higher levels of Serotonin are linked with raised levels of anxiety and obsessive behaviours.  These findings may mean that raised serotonin levels and therefore raised anxiety and obsessive symptoms predate the eating disorder.

Serotonin also appears to play a role in Bulimia and Binge Eating Disorder. It was found that when people with bulimia went without food for long periods of time, they experienced a drop in serotonin(3)(4) which resulted in binge eating.

There is also research exploring serotonin and its link with genetics.

When we are hungry and eat, there is an increase in dopamine, which is thought to lead to a pleasure or reward feeling. Brain scans in people with bulimia show that their brain’s reward pathway is more active than people without bulimia when looking at pictures of food (5).  In people with anorexia, its thought to be the opposite effect. Brain scans showed high levels of cognitive processing (lots of stimulation in the brain) when people with anorexia viewed images of food (6), even after recovery.


It is thought that initially, eating disorder behaviours such as restricting or binging may help reduce feelings of anxiety people may have (7)(8). However, this relief does not last long and a cycle of eating disorder behaviour often begins. Studies around this have been quite small and have explored this behaviour and patterns in very controlled experimental circumstances so may not be accurate for all people.

Some brain studies have shown that grey matter (part of the brain involved in muscle control and processing information from our senses) is at a reduced volume, likely shrunk due to starvation, in people with anorexia. However, one group of researchers (9)found that individuals with anorexia had more grey matter than those without an eating disorder. The grey matter was greater in the front of the brain in an area called the orbitofrontal cortex. This part of the brain is responsible for cognitive processing of things like taste and touch and is used in decision-making. They also found a difference between individuals with anorexia and those without in regards to white matter, which joins the grey matter together and transmits signals between brain areas. The white matter was found to be higher in the front underside of the brain (anteroventral) but lower in the back frontal lobe (posterior frontal) and parietal regions (to do with sensation, perception and sensory input with visual system). The same study found an association which showed that the greater the volume of grey matter in an individual with anorexia’s brain, the less pleasant they found the taste of a sugar syrup. It is thought that the association could be a factor in food avoidance in individuals with anorexia.

Research has also found that people with eating disorders may experience “rewards” differently to those without.(10) Structural neuro imaging (brain scans) have also shown that in both people with anorexia and bulimia, the brain structure is altered which may result in changes that have been associated with taste and reward value. This means that those with eating disorders may not feel the same way as those without in response to “rewards” i.e. eating, exercise.

It is though that grey and white matter can increase following weight restoration (10)(11)which will hopefully improve brain functioning and support cognitive abilities as well as other functions.

It’s important to note that during childhood to adulthood, the brain is developing.  It is thought that the brain continues to develop right up until 25 years of age. Some of the changes are dependent on the onset of puberty, which we know starvation can have a significant impact on.  Puberty is a time when some thinking processes and connections (the grey matter areas) in a person’s brain are lost or strengthened, depending on if they are used.  The process starts at the back of the brain (posterior) and moves to the front (prefrontal cortex – decision making, problem solving and impulse control). During this time the brain uses a specific part (the amygdala) to make decisions which is responsible for dealing with emotions, impulse and instinct behaviour.
A starved state enhances obsessive and specific eating disorder traits, so it’s important to prevent this in order to support the typical development of the adolescent brain.

As you can see, the research around the brain is very complex and still unclear.
However, we do know that eating disorders do impact on the brain’s functioning. This is important as young people’s brains are still developing.
For adolescents, the last part of the brain to fully develop is the frontal lobe, the area to manage and evaluate the consequence of actions. As a parent, it can be really helpful for you to have the young person’s dreams and hopes for the future – the ones they had before they were unwell – in mind, as your loved one may forget these due to the eating disorder. If these are forgotten, the young person may feel that they only have the eating disorder or it’s the only thing they are good at.

Read more here: Adolescent Brain Development by Sarah-Jayne Blakemore & Mo Costandi (2014)


  • There is no one “eating disorder” gene.
  • However, genes may play a role in eating disorder developing.
  • Puberty appears to impact on genes that may play a role in eating disorder developing.

There is some debate as to whether genetics play a role in the development of eating disorders. Historically, some researchers argued that it’s difficult to tell if it’s “nature” or “nurture”. This means that it is still unclear if it is a genetic predisposition that contributes to eating disorders developing, or the surrounding environmental factors.

There is no one gene that causes eating disorders. However, there does appear to be a cluster of genes, known as genomes, that appear to relate to the risk of an eating disorder developing.

Some studies involving identical twins who share identical DNA, have shown that they are 10 times more likely to develop an eating disorder than non-identical twins, despite them both being brought up in the same environment. This leads us to believe that genes do contribute to the “predisposing” factors which increase the risk of an eating disorder developing.

A study by a group of researchers also suggests that puberty may impact on or “activate” genes. The study shows that oestrogen may play a role in increasing the risk of eating disorders in girls. (12)

Personality, Characteristics, Temperament and Starvation

Some known personality traits are associated with people who develop eating disorders. These traits usually pre date the eating disorder developing and are around after a person has recovered.

The traits are often positive and can lead to success in lots of areas of life e.g. can support someone to meet goals and be hardworking, but eating disorders can use these traits to their advantage. The traits can be:

  • Perfectionistic
  • Goal driven
  • Detail focused

These traits are believed to be heritable and are therefore passed on via genes.

It is also common for people with eating disorders to have low self esteem and anxiety.

Dr Janet Treasure an expert and one of the lead researchers in eating eating disorder, speaking about eating disorders.

Environmental & Social

It is a myth that the media causes eating disorders. The reality is that we are all exposed to the same media and not everyone has an eating disorder. However, the media can play a part in fuelling an eating disorder. Social media, magazines, photoshopped images, film & TV, adverts and even shop mannequins influence how we view ourselves, what we think the “ideal” way to look is and can add to unrealistic comparisons. The same goes for specific life styles which can be displayed on social media and terms such as “clean eating”, “detoxing” and  “healthy eating”.  We are also aware clinically, that when healthy living concepts designed to prevent obesity are delivered in a “black and white” way (e.g. all fat is bad), this can have a negative impact on some vulnerable young people.

Peers and social groups may add to the pressure of “fitting in” or competing to “be the best”. Adolescence is a time when the identity of “self” is explored. There may be emphasis on appearance and body image.  Peer groups play an important role in this. Young people who have lower self esteem or are more self critical are often more open to peer pressure or the need to “fit in”. (11)(13)

Being able to express emotions in families is positive and we would encourage it. However, at times of stress, e.g. when an eating disorder invades your family, communication styles can become fraught. Expressed emotion refers to a verbal and non-verbal style of communication that the loved ones of people with mental health difficulties can fall into. This usually comes from a place of high anxiety, stress and frustration and desperately trying to “fix” the problem or shelter your loved one from the distress caused by the illness.

We know that eating disorders and the recovery from these can be incredibly frustrating and distressing for the carer. However, we know that if this style of communication is not addressed it can delay recovery. You can read more about expressed emotion by clicking here to read more in the Skills section and within Janet Treasure’s book, Skills-based Caring for a Loved One with an Eating Disorder or on The New Maudsley Approach website

Expressed emotion is something you may talk about with clinicians involved in your care. It may help to support you and your family in how to communicate in less emotionally charged ways, which is no easy feat when you have an eating disorder monster who has taken over a loved one.

It’s important to note that recovery from an eating disorder is not a linear or straightforward path.  There is no “perfect recovery” path and whatever you’re doing as a parent cannot make a “perfect recovery” happen, because the journey to recovery is never the same.
Try not to be too self critical in thinking that recovery is taking longer than you thought, or be hard on yourself when there is a ‘wobble’. You will be doing your best.
This kind of self critical thinking can be another factor in expressed emotion that people are often unaware of. If you are being critical of yourself, your loved one will notice and think that it may be because they aren’t doing enough for a “perfect recovery”- and as you can see, a cycle may begin.

Clinicians often talk about “Good Enough” caring. This means trying your best when caring for your loved one, as “perfect caring” isn’t realistic or achievable.

Significant Events

Experiencing a difficult or stressful life event can often be a trigger for the beginning of eating disorder behaviours.
Examples of these sort of events can include; starting secondary school, leaving home, going to university, exam periods, difficulties with friends, bereavement, changes in families and conflict at home. Often, change can be difficult to manage and stressful.
A person may lose their appetite when under stress. They may find the unexpected weight loss supports an eating disorder to set in and, subsequently, that the eating disorder initially helps them to manage anxiety.
Eating disorder behaviours such as binging may develop as a way to distract and cope with difficult feelings which may, in turn, develop into an eating disorder cycle.

Starvation can also impact and enhance some of the personality traits and characteristics mentioned in the sections above. This is because starvation impacts on the brain’s cognitive function and then a person’s behaviour. Often when a person is starved, obsessive and rule bound behaviours can increase and become almost unmanageable.

The Minnesota Study was designed to learn how to treat and rehabilitate prisoners of war and people in cities of Europe who were starving. It was conducted in the 1940’s and involved conscientious objectors of World War 2 taking part in an experiment which led them to lose significant amounts of weight. The men in the experiment began to show similar thoughts and behaviours as people with anorexia; obsessive with food, amounts and calories, ritual eating patterns and exercising.

This is EXTREMLY IMPORTANT to remember in the treatment of eating disorders. Being in a starved state can exacerbate eating disorder symptoms and sometimes be the cause of some of the obsessive behaviours we see.

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