Three quarters of eating disorder patients face critical delays to treatment because GPs fail to refer them to specialists, a major study has found.

Those who are a healthy weight are four times more likely to be dismissed by a doctor compared to someone underweight.

This is despite studies showing just six per cent of people with eating disorders have an unhealthily low BMI. 

Men, patients aged over 30 and those living in the North East of the country are also more likely to miss out on a referral, according to the study.

Writing in the prestigious medical journal The Lancet, the researchers - from Canada and the UK - say the findings suggest medics are failing to recognise eating disorders other than anorexia.

While anorexia is perhaps the best-known condition, binge eating disorder, bulimia and avoidant/restrictive food intake disorder (ARFID) are far more common.

A recent report found some eating disorder patients in England are waiting nearly two years for specialist care. The average wait is 42 days, according to an audit by the Healthcare Quality Improvement Partnership.

Studies show that patients who access treatment within three years of the onset of illness have the best chance of a full recovery.

For the study, researchers from Kings College London and the University of British Columbia in Canada analysed a decade of health records of 35,000 patients in England and Northern Ireland aged 18-80. 

All the patients in the study had received a diagnosis of an eating disorder at some point over the 10 year period.

The scientists looked for referrals to eating disorder services following an initial GP appointment, and took note of individual characteristics such as gender, age, ethnicity and area of residence. 

They found that 76 per cent of patients did not receive a GP referral to specialist services.

Anorexia patients who were underweight - defined as having a BMI below 18 - were four times more likely to be referred to specialist care compared to those who were not underweight.

Patients do not have to be abnormally thin to fit the criteria for diagnosis, but they are regarded as 'atypical'. 

Guidelines for GPs by the National Institute for Health and Care Excellence state patients must 'immediately' be referred to appropriate services if an eating disorder is suspected.

The findings raise questions about how 'consistently' eating disorders other than anorexia are being 'identified and acted upon' by GPs, the authors said.

'There's need for better GP education and improved screening tools across all diagnoses.

'Especially because eating disorders can be equally serious regardless of a person's weight.'

They also suggest that allowing patients to refer themselves directly to eating disorder services, rather than requiring a GP referral, could help reduce delays in accessing treatment.

Some 3.5 million people in the UK suffer from an eating disorder, with the most common being atypical types (ARFID), followed by binge eating disorder. 

Around half of anorexia sufferers will never make a full recovery, while the same is true for roughly a third of bulimia and binge eating patients, according to NICE.

Recent NHS data show the prevalence of eating disorders in 11 to 16 year-olds increased five-fold between 2017 and 2023. 

Meanwhile, the results of a poll published in April revealed almost half of primary teachers in England see pupils with eating disorders.

Experts have blamed multiple factors for the rise in the conditions, including more time spent on social media apps like Instagram, educational pressure and the residual effect of lockdowns. 

For free support call the UK's leading eating disorder charity Beat on 0808 801 0677. Lines are open Monday to Friday, 3pm to 8pm. Alternatively, visit their website.