The main eating disorders: binge eating, bulimia, anorexia, ARFID and OSFED

Last updated on May 17th, 2020

Anorexia nervosa

Most countries use the diagnostic criteria of DSM-5 (Diagnostic & Statistical Manual of Mental Disorders, 5th edition). To be diagnosed as having Anorexia Nervosa a person must display:

  • Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health; significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected
  • Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though the patient’s weight is already significantly low
  • Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight

There are two types of anorexia: restricting anorexia and binge-purge anorexia. The risks to health come from a low body weight, from insufficient nutrition or fluids, from electrolyte imbalances, and suicidality.

Laypeople tend to associate anorexia with emaciated bodies, and indeed in the past, a very low weight was a necessary criterion for diagnosis. But with DSM-5 the physican is to consider whether the person has 'significantly low body weight' in relation to the person's own needs.

With anorexia, a person is absorbed with preoccupations around food, and usually also around exercise and around body shape. The person may have a sense of an anorexic presence bullying them to restrict at all costs, praising them for their efforts or abusing them when they eat or relax. It may be an incessant voice in their head. This gets in the way of concentration on school or friends.

All the same, young people with anorexia can be highly performing in school – the model pupil. Biological mechanisms kick in with anorexia, which seem to give the person energy, drive and even bouts of happiness. Feeling empty, without food, feels right. They may be insensitive to hunger, and at other times be torn between extreme hunger and internal rules. The person is likely to be at his or her worst when going through treatment, as it is horrific for them to eat and gain weight.

The drive to exercise may be enormous. In primary-school-age children it may be particularly evident as a restless, anxious state, where stillness is near-impossible. An exercise compulsion may also be part of the self-punishing nature of anorexia, and often it is a deliberate strategy to lose weight.

What is anorexia

While weight and nutrition are low, and sometimes even after these have been restored, the person may suffer from depression, anxiety and obsessive-compulsive disorder (OCD). There may be self-harm and suicidality. These conditions share some of the risk factors for an eating disorder and may have developed before the eating disorder, or they may only be a problem while the person is malnourished.

As long as they can restrict without anyone intervening, people with anorexia may go for weeks or months of being on a high, appearing happy and energetic, even though they are effectively starving. Without treatment, people with anorexia will become underweight, and the more they lose weight, the more brain function is affected. Thinking becomes increasingly distorted, and eating becomes more horrific. There are more and more eating or exercising ‘rules’. Breaking a rule feels dangerous (note the overlap with OCD) and the person has a compulsion to compensate or atone for food, rest and anything that is enjoyable.

Many (but not all) people with anorexia also suffer from body dysmorphia: their brain sends them distorted signals that they are horribly fat. This may vary depending on their level of stress at any moment.

Many (but not all) people with anorexia have a great fear of gaining weight. Yet there cannot be recovery without weight-restoration.

In addition, the brain processes responsible for anorexia also create anosognosia in a number of sufferers, and therefore a lack of motivation to get treatment: the person does not believe they are ill, or cannot recognise that their situation is serious. Whereas ‘denial’ is a psychological defence mechanism, with anorexia there can truly be a disconnect between what others see and what the person perceives.

At times, the person may have motivation to get better, but eating is so horrible that they cannot keep it up without support.

With the binge-purge type of anorexia, hunger occasionally drives the person to eat an amount which to their mind is enormous, though it may or may not be. After this the self-starvation and exercise is ramped up.

In the UK,  the NICE treatment recommended first and foremost for anorexia is anorexia-focused family therapy (FT-AN). This treatment requires parents to take charge of nutrition, weight gain and normalising behaviours. The young person gets a lot of support and the treatment works even when they have little motivation to beat the illness. This website and my book are in line with this approach.

If the experts have good reasons not to deliver FT-AN, then NICE recommends two possible individual therapies, where it will be the sufferer’s task to achieve the same aims.

If your son or daughter is in the early stages of treatment for anorexia, they will need a support from the school, otherwise they will not progress and may continue to get worse. This usually means some level of supervision or support to eat meals and snacks, and possibly to stop exercising or vomiting.

Binge eating disorder

People suffering from binge-eating disorder have episodes (at least once a week on average) of eating unusually large amounts of food in a very short while. During this time they have no control over their eating and may be in a trance-like state. After a binge they are distressed, ashamed, and full of self-loathing. Some may then go for hours or days with little or no food, battling hunger, recruiting extreme willpower, planning weight loss in great detail. If so, they may be malnourished, with medical risks just as serious as those of an underweight person.

In spite of all their efforts, soon they are compelled to binge again. Some secretly plan their binge in great detail.

At home, if the secret is out, there may be a lot of tension as the person consumes the family’s food reserves at a great rate. Shopping for food may drain the family budget.

People suffering from binge-eating disorder live with highly distressing negative thoughts about themselves, placing them at risk of suicide, and at the very least, making it hard to concentrate on school work.

People with binge-eating disorder often have a higher body weight than average, or it may yo-yo as they try and control their weight.

According to NICE guidance for the UK, the recommended treatment for adolescents with binge eating disorder is CBT-ED, a cognitive-behavioural therapy developed for eating disorders.

Part of the treatment involves the person having regular meals as this breaks the cycle of hunger and binge. This is hard for the person if they are beating themselves up about a binge. If your son or daughter is going to school, you may need to ask them to supervise meals and snacks.

For an insight into what binge-eating disorder is like for the sufferer, listen to this podcast :Tabitha Farrar interviewing Ryan Sheldon.

Bulimia nervosa

Bulimia is like binge-eating disorder, except that the person tries to compensate for their binges with some form of purging: vomiting, taking laxatives or diuretics, fasting, or excessive exercise. There can be just as much yo-yoing of feast and famine.

In addition to the suicide risk, there is a significant risk of sudden death from the imbalance in electrolytes caused by vomiting or from large quantities of laxatives or diuretics. The person may look fine even though they are at serious risk and need regular medical checks.

They may think about food all day long, beating themselves up for their last binge, and exhausting themselves with punishing fasts or exercise.

Their body weight is usually average.

The NICE guideline for treating bulimia in the UK recommends a specialised form of family therapy (FT-BN). It is very similar to family-based treatment for anorexia, which is what I know best. It places parents in charge of regular meals and normalising behaviours, but also makes use of the motivation the person often has to stop bingeing.

It takes a lot of effort, consistency and courage for someone to end the habit of vomiting and to eat what they need.

The NICE guideline gives a second option for treatment: cognitive-behaviour therapy for eating disorders (CBT-ED). Just like with binge-eating disorder, the person will be required to normalise their behaviours even though this raises their anxiety, and they may need support to manage this.

Whichever treatment is in place, if your son or daughter is attending school they may need some level of supervision to ensure that meals and snacks are eaten, as any missed meals may trigger biological mechanisms that lead to bingeing later. The school may also need to supervise that they cannot use toilets for an hour or two after a meal.

ARFID

ARFID is quite different from the other eating disorders. People may be terribly deficient in nutrition or in weight, but they don't have psychological difficulties around weight, body shape, calories, exercise or a nasty internal voice. It's just really hard for them to eat enough in terms of quantity or variety.

According to the criteria of the DSM-5 diagnostic manual, to be diagnosed with Avoidant/Restrictive Food Intake Disorder (ARFID) a person must display:

“An eating or feeding disturbance as manifested by persistent failure to meet appropriate nutritional and/or energy needs associated with one (or more) of the following:

  • Significant loss of weight (or failure to achieve expected weight gain or faltering growth in children).
  • Significant nutritional deficiency
  • Dependence on enteral feeding or oral nutritional supplements
  • Marked interference with psychosocial functioning
  • The behaviour is not better explained by lack of available food or by an associated culturally sanctioned practice.
  • The behaviour does not occur exclusively during the course of anorexia nervosa or bulimia nervosa, and there is no evidence of a disturbance in the way one’s body weight or shape is experienced.
  • The eating disturbance is not attributed to a medical condition, or better explained by another mental health disorder. When is does occur in the presence of another condition/disorder, the behaviour exceeds what is usually associated, and warrants additional clinical attention.”

Bland food - ARFID

ARFID is an umbrella term, that covers a number of rather different presentations — a mixed bag. The causes of ARFID are likely to be quite different to those of other eating disorders. For example:

  • Minimal eating: it looks like anorexia, but without the concern about body shape. People show little interest in food, seem to experience no hunger and are easily full, and this may have been the case all their life. Their weight and height are usually in the lower centiles.
  • Sensory food avoidance and selective eating: people may only tolerate a few bland foods, or certain colours or textures. They may get very distressed from certain goods touching each other on the plate. Unlike someone with anorexia they are not trying to eat low-calorie foods. They may have sensory distress around tasting, biting, chewing, feeling full. Some may be on the autistic spectrum.
  • Anxiety or phobia: these people may have a phobia after having chocked on food (emotophobia), or vomiting or diarrhoea. This is quite different from the ‘fear foods’ of anorexia.

Treatment has to be tailored to the individual. It may require patience and small steps, as in Kay and Toomey's 'Steps to eating'. Expectations may also be individual: whereas with the other eating disorders we aim for complete recovery, it may be that with ARFID, it's good enough for some people to get to a stage they can simply eat flexibly enough to be healthy and sociable. Or perhaps this attitude only reflects how the field is still in its infancy.

As always, early intervention matters. Some people's ARFID presentation is very similar to anorexia, and I hear that for some — especially when hospitalised alongside anorexia patients — the disorder can morph into anorexia, with concerns about calories, body shape etc.

As the ARFID classification is still quite new, we don’t have much data on how common it is, and no perfect diagnostic tool for it. Eating disorders dietician Paola Falcoski, who specialises in ARFID and impressed me with an excellent presentation at a conference, pointed me to this semi-structured interview). Listen to her whistle-stop tour of treatments for ARFID on this podcast.

According to Psychiatrist Dasha Nicholls, ARFID occurs in adults but it is one of the more common eating disorders among young children (sometimes almost from birth) or among people with autism spectrum disorder (ASD). In boys age 12, you might expect more ARFID than anorexia – the reverse with girls.

Here are books recommended by Paola Falcoski for ARFID:

Parents of children with ARFID like those and also these below:

ARFID is quite common among autistic people, so I am looking forward to the publication of this book on autism and eating disorders in teens (I tell you more about the book here):

Many of the treatment approaches I talk about on this website are unlikely to be appropriate to ARFID. A parent emailed me this:

The patient most likely wants to eat and gain weight, so the more heavy-handed or punitive techniques employed by some parents of younsters with anorexia should be avoided. We should never place demands on an ARFID patient to eat a particular food they are not comfortable with. First, it’s not likely to work, and second, it risks creating more anxiety and making the food aversions worse. There is a difference between anorexia ‘fear foods’ and ARFID food aversions.

For more parent expertise, see the ARFID page of the FEAST forum here. These parent groups may also help you: SED / ARFID Parents Support GroupARFID parent support UK/IrelandARFID: Avoidant/Restrictive Food Intake Disorder, and  Mealtime Hostage.

OSFED

OSFED stands for ‘Other Specified Feeding or Eating Disorder’ in the diagnostic manual DSM-5.

A person with OSFED presents with feeding or eating behaviours that cause significant distress and significantly impair areas of functioning, while not meeting the full criteria for any of the other feeding and eating disorders.

It is the most common of all eating disorders diagnoses and is no less serious than binge eating disorder, bulimia or anorexia.

When someone shows most – but not all—of the symptoms used to diagnose anorexia, bulimia or binge-eating disorder, they may get the OSFED diagnosis.

In general the treatment for OSFED needs to be the same (and taken just as seriously) as for the most similar illness, whether anorexia, bulimia or binge-eating disorder. When you read my resources, please assume I am including the OSFED versions of anorexia, bulimia and binge-eating disorder.

Categories within OSFED are:

Atypical Anorexia Nervosa

The word 'atypical' is poorly chosen as this condition is more prevalent than anorexia and just as serious. All the anorexia criteria are met, except that the individual isn't considered to have 'significantly low body weight'.

Many argue that this distinction should not exist as it may to reinforce the dangerous notion that you can tell if someone has anorexia from their body shape.Remember that the definition of 'significantly low' weight should, according to DSM-5, refer to the individual's 'developmental trajectory', and 'physical health'. All the same, too many physicians still base their diagnosis on a person's current BMI in relation to a statistical chart. That means they may miss that the person has a significantly low weight for their own situation and therefore ticks the boxes for 'anorexia nervosa'. The reason that matters is that those same physicians may underestimate the person's need for urgent treatment. The biggest risk is with people who have lost a dangerous amount weight, or a child who has failed to grow, yet their current weight still comes up as 'normal' on a statistical BMI chart.

If a physician decides there is no 'significantly low body weight', the  person will then be diagnosed with 'atypical anorexia'. This is just as serious a condition as anorexia (medically and psychologically), requiring just as urgent a treatment.  Many sufferers have beliefs and behaviours that make it will likely they will get worse. Often it's only a matter of time before weight loss puts them in the 'anorexia nervosa' category. Early intervention boost the effectiveness of any treatment, so insist on prompt, specialised treatment, just as you would for someone who looks emaciated.Note that thanks to books and the internet, there are many young people diagnosed with atypical anorexia, who would most probably have ticked the boxes for anorexia if their parents were not so well-informed and skilled at getting them to eat.

Binge Eating Disorder (of low frequency and/or limited duration)

All of the criteria for BED are met, except at a lower frequency and/or for less than three months.

Bulimia Nervosa (of low frequency and/or limited duration)

All of the criteria for Bulimia Nervosa are met, except that the binge eating and inappropriate compensatory behaviour occurs at a lower frequency and/or for less than three months.

Purging Disorder

Recurrent purging behaviour to influence weight or shape in the absence of binge eating

Night Eating Syndrome

Recurrent episodes of night eating. Eating after awakening from sleep, or by excessive food consumption after the evening meal. The behavior is not better explained by environmental influences or social norms. The behavior causes significant distress/impairment. The behavior is not better explained by another mental health disorder (e.g. BED).

Rumination disorder and PICA

I include these only because they are they are part of the DSM 5 eating disorder diagnostic categories. The causes and the treatment are quite different from those relating to the other disorders. Rumination disorder involves the repeated regurgitation of food (if it is not part of one of the other eating disorders). Pica involves eating substances that are not food.

UFED

UFED stands for ‘Unspecified Feeding or Eating Disorder’.

The individual presents with feeding or eating behaviours that cause clinically significant distress/impairment of functioning, but do not meet the full criteria of any of the other feeding or eating disorder criteria. This classification may be used when there is insufficient information to make a more specific diagnosis. One example of UFED is people who have recurrent binge eating without marked distress.

A note on the old EDNOS

The previous diagnostic manual, DSM-IV, had a category named EDNOS (‘Eating Disorder Not Otherwise Specified’). Many of the people diagnosed with EDNOS would, under the new diagnostic system, be categorised as having anorexia, bulimia, or binge eating disorder (binge eating disorder did not exist as a category in DSM-IV). And some would nowadays be in the OSFED category.

Not in the diagnostic manual but (equally) important

On the next page I describe issues that are not diagnosable eating disorders but have similarities and may be equally serious:

  • Diabulimia
  • Orthorexia
  • Drunkorexia
  • Muscle dysmorphia / Bigorexia / Reverse anorexia


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