Dr Dominique Thompson offers 10 top tips for general practice on the role of GPs in managing eating disorders, including signs to look out for, the right questions to ask, and the need for referral without delay


Dr Dominique Thompson

Read this article to learn more about:

  • how many people on an average GP list may have an eating disorder
  • ways that eating disorders may present and how to ask questions
  • physical and mental health assessments and how and when to refer.

Eating disorders (EDs) have the highest mortality (from suicide or complications of the disorder) of any mental health condition and are associated with considerable co-morbidities (such as anxiety, depression, self-harm, and personality disorder),1–4 yet it is not uncommon for them to continue to be considered a ‘phase’ or ‘attention-seeking behaviour’.

The range of conditions and behaviours classed as eating disorders (including anorexia nervosa, bulimia nervosa, binge eating disorder, and other specified feeding and eating disorders [OSFED]), cause a huge amount of distress and concern to patients and to their families and friends.

NICE updated and replaced its guideline on eating disorders in 2017 with NICE Guideline (NG) 69 on Eating disorders: recognition and treatment,1 and there are other useful sources of information and guidance for primary care practitioners, as referenced below.

About 725,000 people are thought to have an eating disorder in the UK, and it is now likely, according to NG69, that 1 in 4 of them may be male. The most common age of presentation in both males and females is 13–17 years,1 but eating disorders can of course develop at any age. A recent study by the charity Beat5 demonstrated that, on average, there was a three-and-a-half year period between first onset of symptoms and receiving treatment. The initial delay of over 18 months was the time taken for people to recognise symptoms in themselves, then they waited a further year before seeking help: this means that by the time someone sits in front of their GP asking for support, they may have been unwell for almost 3 years.5

The final delay was in GPs not referring immediately for appropriate assessment and treatment, although the guidance now is to ‘refer immediately’.1,5 Early treatment should be prioritised for those with, or at risk of, severe emaciation.1

1. Be alert to eating disorders—‘think ED’

Some healthcare professionals comment that they ‘never see’ eating disorders; however, eating disorder prevalence suggests that an average GP list of 2000 patients is estimated to have 1–2 patients with anorexia, 18 with bulimia, and up to 10% of the young female patients on the list will be using weight reduction techniques.6 Be alert to the possibility of eating issues when patients present with non-eating related symptoms, and ask questions about eating issues when patients present with relevant symptoms.

2. Be aware of common presenting complaints

Gastrointestinal upset, menstrual disorders (such as amenorrhoea), request for allergy testing (or gluten intolerance), constipation, infertility, and ‘weight worries’ on the contraceptive pill are all common presenting complaints in people with eating disorders.1,7 People very rarely seek help directly for the eating disorder as they may not view it as a problem.4,8 The eating disorder is likely to be serving a purpose to the individual, providing relief at stressful times, exerting control in at least one area of their difficult life, or (in their view) managing their weight, so they may not be keen to discuss it; however, the risks of EDs are so high that healthcare professionals cannot afford to ignore the signs.8

Some examples of sensitive and helpful questions to ask are provided in Box 1. Try to enquire about any control (or lack of control) the person displays over food intake, any restrictive and compensatory behaviours, as well as secretive behaviours, alongside other mental health symptoms such as low mood, self-harm, anxiety, guilt, shame, and so on.

Box 1: Suggested questions to ask

  • Do you worry a lot about your weight? Maybe too much?
  • You look quite slim. Does that worry you at all?
  • Do you spend a lot of time thinking about your weight and what you eat?
  • Does your weight affect the way you feel about yourself?9
  • Do you worry that you have lost control over how much you eat?9
  • Do you ever eat in secret?9
  • Do you make yourself sick when you feel uncomfortably full?9

3. Eating disorders are about control

To successfully support patients with eating disorders it is important to remember one thing—these conditions are about control, and the food/eating habits are often the only behaviours that the person feels able to control in what may be a very stressful, pressured, or chaotic life, or if they have suffered trauma in their past.10

If they have been bullied, abused, or are under enormous psychological pressure, then the one thing they may still feel able to control is what does and doesn’t go in their mouth (anorexia). With bulimia, there is both control and a lack of control, as they try to compensate for the bingeing behaviours with exercise, purging, or sometimes diuretics and laxatives.

When addressing their issues, it is unhelpful to focus on the food primarily (avoiding inducements to ‘just try to eat a bit more’ for example in anorexia), and more helpful to consider what in their life has led to the distressing behaviours. Helping them to recover will likely be a slow and bumpy process, a marathon not a sprint, and building a relationship with them over time will be crucial for their recovery.

4. Early intervention = better prognosis, so refer early

NICE Guideline 69 on eating disorders recommends that referral by the primary care team should be ‘at the earliest opportunity’ (in fact it also uses the word ‘immediate’), ideally to a community-based specialist ED team.1 There is no doubt that the earlier people receive treatment, the better their outcomes will be.1,11 If there is no specialist team locally, refer the patient to the psychiatry service for assessment and access to evidence-based therapy.

5. Don’t rely on single measures to determine referral or treatment

There has been a considerable amount of discussion on social media about people being turned away from support or treatment because their weight wasn’t ‘low enough’ or they did not in some way meet specific criteria, but NICE guidance is explicit about this:1

  • ‘Do not use single measures such as BMI or duration of illness to determine whether to offer treatment for an eating disorder.

Therefore, if clinicians suspect that someone has an eating disorder from their clinical symptoms and history, they should refer the person for specialist assessment and triage to appropriate evidence-based therapy. Referral should not be delayed on the grounds of BMI or appearance, for example, nor should the clinician suggest that the patient ‘sees how it goes’ because the person has only been losing weight or bingeing and purging ‘for a month or two’, and so on.

6. Take bloods and some basic measurements

Eating disorders are high risk, so it’s important to carry out a physical and mental health risk assessment at the first appointment, although you might need to invite the patient back when they feel comfortable to be weighed, to have their pulse and BP assessed, and for bloods to be taken. See Box 2 for which blood tests are needed and what to look out for.

Box 2: Bloods to take at first appointment2

  • Full blood count
  • Urea, electrolytes, and creatinine
  • Creatine kinase
  • Glucose
  • Liver function tests
  • Magnesium
  • Phosphate
  • Calcium
  • Bicarbonate
  • Thyroid function test and erythrocyte sedimentation rate (first time only to rule out other conditions).

What are we looking for in the bloods screen?

  • Low potassium from vomiting or laxative abuse
  • High bicarbonate from vomiting
  • Low bicarbonate from laxative abuse
  • Low magnesium from diarrhoea
  • Low phosphate from malnourishment
  • Low haemoglobin (90–120 g/l)
  • Low white cell count (2–4 × 109/l)
  • High serum alanine aminotransferase/serum alkaline phosphatase (ALT/ALKP)
  • Low glucose
  • Low sodium.

A quick tip for weighing someone who is reluctant to get on the scales is to invite them to step on backwards, so that you can see the weight but they can’t.

The patient may need an electrocardiogram (ECG) if they have purging behaviours, use laxatives, have lost significant weight, are bradycardic, hypotensive, or have low potassium.1,2 The King’s College London Guide to the medical risk assessment for eating disorders2 is invaluable as a tool for reviewing bloods, what to look for, and when to refer.

Risk assessment of mood and suicidality is also essential.

7. Review patients who are not receiving treatment

Invite patients with ‘anorexia nervosa not receiving ongoing treatment’ to a review appointment at least annually.1 The appointment is to allow both a physical review, to include the same investigations as at the first appointment, and to review the patient’s feelings about referral to a specialist team. It is also an opportunity to review their mood and mental health in general.

8. Treat symptoms, complications, and co-morbidities

While medication alone is not recommended for any eating disorders,1 GPs can support their patients by evidence-based treatment of co-morbidities such as anxiety or depression, or by mitigating some of the complications and risks that are associated with eating disorders.

NICE advises against referral to a dietitian alone, without a multidisciplinary approach, but it is important to recommend age-appropriate, oral multivitamins and minerals for patients with anorexia, as well as prescribe supplementation of potassium or other electrolytes if required.

Oesophageal reflux may respond well to proton pump inhibitors (PPIs), and referral to a dentist is helpful if the person is vomiting regularly.

The NICE advice around bone protection changed in the recent guidance, and the oral contraceptive pill is no longer routinely recommended for young women with anorexia; it is therefore now best to discuss cases with endocrine colleagues or the specialist ED team, as a bisphosphonate may be helpful if the patient is aged over 18 years, or transdermal or incremental oestrogen doses if they are aged 13–17 years.1

It is also worth discussing dual energy X-ray absorptiometry (DEXA) scan requirements with specialist ED colleagues, on a case-by-case basis.

9. Refer same day for specific ‘red flags’

The King’s College London risk assessment guide2 helpfully indicates when to be ‘concerned’ and when to raise the ‘alert’, which can be interpreted as when to refer ‘within a week’ and when to refer ‘same day’.

The same-day red flags include:

  • BMI <12 kg/m2
  • weight loss of >1 kg/week
  • pulse <40 bpm
  • blood pressure <80/60 mmHg
  • abnormal bloods—
    • haemoglobin <90 g/l
    • white blood cell count <2.0 × 109/l
    • potassium <3.0 mmol/l
    • glucose <2.5 mmol/l
    • liver function tests more than twice the upper limit of normal.

10. Quote NICE guidance to support urgent referral

When the patient in front of you needs urgent care from hospital colleagues, it can sometimes be challenging to communicate concern or the need for admission. If the patient is compromised, unwell, and has abnormal bloods, then speak to the appropriate specialist team and be confident in your assessment of the situation. It can be helpful to have the NICE wording to hand, to ensure that everyone is ‘singing from the same hymn sheet’:1

  • ‘Provide acute medical care (including emergency admission) for people with an eating disorder who have severe electrolyte imbalance, severe malnutrition, severe dehydration or signs of incipient organ failure.’ (NICE NG69, para 1.10.3)
  • ‘Admit people with an eating disorder, whose physical health is severely compromised to a medical inpatient or day patient service for medical stabilisation and to initiate refeeding, if these cannot be done in an outpatient setting.’  (NICE NG69, para 1.11.1)

Some useful additional resources can be found in Box 3.


Eating disorders have a significant mortality and complication rate, and their severity and importance should never be underestimated. Ask the right questions, build a relationship with the patient, and refer without delay.

Dr Dominique Thompson

GP, Bristol

Member of the guideline development group for NG69

Box 3: Additional resources

NICE Guideline 69 on Eating disorders: recognition and treatment

RCGP e-learning module on eating disorders

Network-ED free website

British Eating Disorders Society

National Eating Disorders Association

Charities for patient and carer support

Beat eating disorders

Anorexia & Bulimia Care

SEED eating disorder support service

Men Get Eating Disorders Too

RCGP=Royal College of General Practitioners


  1. NICE. Eating disorders: recognition and treatment. NICE Guideline 69. NICE, 2017. Available at: www.nice.org.uk/ng69
  2. Treasure J. A guide to the medical risk assessment for eating disorders. King’s College London; South London and Maudsley NHS Trust, 2009. Available at: www.kcl.ac.uk/ioppn/depts/pm/research/eatingdisorders/resources/GUIDETOMEDICALRISKASSESSMENT.pdf
  3. Thompson D. Boys and men get eating disorders too. Trends in Urology & Men’s Health. 2017; 8 (2): 9–12.
  4. Herzog D, Keller M, Lavori P et al. The prevalence of personality disorders in 210 women with eating disorders. J Clin Psychiatry  1992; 53 (5): 147–152.
  5. Beat eating disorders website. Three-and-a-half-year delay for eating disorder treatment worsens illness and cost to the NHS. www.beateatingdisorders.org.uk/news/three-half-year-delay-eating-disorder-treatment (accessed 19 February 2019).
  6. King’s College London: Section of Eating Disorders, Institute of Psychiatry. A general practitioner’s guide to eating disorders. Available at: www.kcl.ac.uk/ioppn/depts/pm/research/eatingdisorders/resources/GPsGUIDE20TOEATINGDISORDERS.pdf
  7. Greater Manchester West Mental Health NHS Foundation Trust. Guidelines for GPs and other professionals: Eating disorders. Available at: www.gmmh.nhs.uk/download.cfm?doc=docm93jijm4n809.pdf&ver=1405
  8. Herman E. The purpose of the eating disorder. Eating Recovery Center website, 2015. Available at: www.eatingrecoverycenter.com/blog/2015/12/31/the-purpose-of-the-eating-disorder-by-ellie-herman-ma-lpc-ncc
  9. Cotton M, Ball C, Robinson P. Four simple questions can help screen for eating disorders. J Gen Intern Med 2003; 18 (1): 53–56.
  10. Froreich F, Vartanian L, Grisham J, Toyuz S. Dimensions of control and their relation to disordered eating behaviours and obsessive-compulsive symptoms. J Eat Disord 2016; 4: 14.
  11. Natt A. Improving access to eating disorder services. BMJ 2018; 360 (8139): k382.