There has been an unprecedented rise in the number of teenagers with eating disorders in the UK, new NHS figures have revealed.

The number of 13 to 19-year-olds admitted to hospital with illnesses relating to eating disorders has risen from 959 in 2010/11 to 1,815 in 2013/14 – an increase of 89 per cent in just three years. That figure is almost triple the number of sufferers in 2003/04, when 642 teenagers were admitted.

The large majority of those admitted are female, and the average age is 15. Experts warn that the figures aren't totally conclusive, as in many cases the sufferer does not go to hospital.

Rachel Welch, director of selfharmUK, says that the rise in cases is "alarming". She told Christian Today that mental health services for young people have been cut dramatically in the last ten years, meaning that "only the most severe cases make it through the door".

"As a nation we are generally very disordered in how we eat; food meets a physical need but has increasingly become attached to our emotions – eating disorders often aren't actually about size, but being in control," she added.

Speaking to the BBC, Royal College of Psychiatrists spokeswoman Dr Carolyn Nahman said that pressures from social media are becoming a growing problem. "Literally with one click of a button very vulnerable young people are able to access 10,000 images of 'perfect looking' people which places them under a lot of pressure," she explained. A ruling published just today revealed that an Yves Saint Laurent advert has been banned by the Advertising Standards Authority (ASA) for featuring a model who looks unhealthily underweight. The ASA branded the ad "irresponsible".

"Young people who look at these images often develop body image dissatisfaction, quite low self-esteem, because they're constantly comparing themselves to these perfect images. This is a risk factor for disordered eating and more serious eating disorders which can prove fatal," Nahman said.

Welch agrees. "Pressure from social media is certainly contributing, with young people being exposed to images and content that may have previously only been found on pro-eating disorder websites being shared on Facebook, Instagram etc giving young people a warped sense of 'normal'," she said.

"Teenagers have never been more confused about their identity, with conflicting messages about what they should or shouldn't be doing/wearing/achieving coming from parents, school, peers, social media and celebrity culture. This causes anxiety, fractures self-image and leads to a desperate lack of fulfilment – all of which can contribute to and prolong disordered eating."

The Church has a responsibility to engage with all young people, Welch added, but specifically those who are most vulnerable. It is vital to encourage and nurture "an identity based on biblical truths and Christ-centred wholeness," she said. "To be the voice that says they are special, valued and have worth just as they are in a way that will resonate, have meaning and change lives – however counter cultural that may seem to young people."