‘No talk about food. It’s boring and it’s unhelpful,” announces Keanu Reeves playing (hold on to your hat) a doctor specialising in eating disorders in To the Bone, the much-discussed upcoming film about anorexia, starring Lily Collins and distributed by Netflix. And this is excellent advice, but it can be hard to see beyond the surface issues when you are dealing with someone who is literally starving themselves to death: the shoulder blades jutting out like birds’ wings, the food hidden under place mats, the limbs so wasted you can circle them with your fingers. It is even harder if a part of you is turned on by skinny, self-destructive women, as the movies invariably are, and this one definitely is.

It’s not easy to make a good movie about anorexia, which is why almost – almost – none exist. How to depict a mental illness that – unlike, say, schizophrenia or bipolar disorder – has such a well-known and hard-to-fake physical manifestation? To the Bone’s writer-director, Marti Noxon – who based the movie on her own experiences with the illness – got around this by getting Collins, who has spoken about her own struggles with eating disorders, to lose an astonishing amount of weight so that she looks credibly anorexic on screen. Given how thin female actors now have to be just to look “slim”, your heart breaks at the thought of how much weight she must have lost to look so painfully ill.

To the Bone has been wildly praised since it debuted at Sundance in January, and I can only assume this is because critics get weirdly overexcited when actors undergo physical transformations. The truth is To the Bone is not a good movie about anorexia. In fact, it is a bad one. We could talk all day about the ethics of hiring a young woman who is known to be vulnerable to eating disorders, and then telling her to lose weight to look anorexic, but let’s give Collins the benefit of the doubt and say she is an adult woman who is free to make her own career choices. Instead, let’s talk about To the Bone’s real problem, which is that it is shallow, sexist and sick.

The only justification for making a movie like this is that it is going to provide some insight into a much-discussed if little understood problem, a requirement Netflix’s earlier and similarly exploitative foray into self-destructive young women, 13 Reasons Why, notably failed to meet. But from the very first scene it is obvious that To the Bone leans on some wearily outdated tropes. We first see Ellen (Collins) in an in-patient unit, in which she and her fellow anorexia patients are beautifully styled in the universally recognised signifiers of crazy-but-sexy young women: heavy kohl eyeliner and mascara, Tank Girl-esque distressed clothing and biker boots. We have gone from 1999’s Girl, Interrupted to 2017’s Meal, Interrupted.

From there on, the anorexia stereotypes are ticked off with the regularity of hospital mealtimes. The movie disregards its own advice almost immediately about not focusing on the food and does so with voyeuristic intensity, without ever asking why so many women feel so unhappy, and why they then turn this unhappiness on themselves. All the anorexia patients, with one male exception, are young, attractive, middle-class white women, when the illness affects a far broader demographic. Reeves, as Ellen’s psychiatrist, Dr Beckham, is a self-described “unconventional” doctor, who proves his unconventionality by swearing occasionally and insisting his methods are totally different from anyone else’s (they’re not: they rely on therapy and healthy eating, as almost all eating-disorder treatments do). He also clearly enjoys his power over his mainly female patients and a braver, less conventional film would have explored this more. Instead, To the Bone merely accepts the doctor’s version of himself as the brilliant, patriarchal medical professional who can fix women.

I am going to show my cards here and say that I am undoubtedly biased on this issue, because I had a doctor similar in some regards to Beckham during my first three hospitalisations: Dr Peter Rowan, then based at the Priory in Roehampton. I was only 14 when I first met him but even then it seemed to me that he revelled too much in his authority over a ward of vulnerable women, who in turn viewed him as god-like. In 2011, 18 years after we parted ways, he was struck off when it emerged he had what was described as “a blurred and secretive” relationship with a female patient, who left him more than £1m in her will.

Now, clearly, there are plenty of excellent male psychiatrists who work with eating disorders, and my experience was an outlier. But given that anorexia is often a form of rebellion against gender norms, with female and male sufferers rejecting, respectively, sexualised femininity and macho masculinity by starving themselves, it is ironic that a movie should re-enact such gender cliches. The doctor is a man, the nurse is a woman, the women in Ellen’s life (her mother, stepmother and her mother’s girlfriend) are all self-obsessed and bitchy, her father is absent but hard-working. The one male anorexia patient is wise and selfless in a way none of the female patients are, and – spoiler alert – he, along with the male doctor, helps to save Ellen. Many brilliant women are now the leading lights in eating-disorder treatment, not least the woman who treated me through my last three hospital admissions, Professor Janet Treasure, now the director of the Eating Disorder Unit at the Institute of Psychiatry at King’s College, London. So the idea that all that these hysterical female anorexia patients need is a couple of calm men to save them from themselves is, to put it mildly, grating. The film even tacks on a frankly ludicrous romantic subplot, and anyone who thinks patients with eating disorders are making out with one another on hospital wards has clearly never bothered to Google what starvation does to a person’s libido.

There is currently a petition online demanding that Netflix pulls the show for two reasons. The first, that it might trigger sufferers, is a point I feel sympathy for but cannot agree with. Legislating against anything that might trigger the mentally ill or vulnerable is an impossible game of Whack-a-Mole. But the petition’s other complaint, that it glamorises anorexia, will be less easy for the film-makers to dismiss. Contrary to what the character of Ellen might suggest, anorexia is not all thigh gaps and eyeliner. By the time I was admitted to hospital for the first time when I was 14, most of my hair had fallen out, I could barely walk because I was so cold and my knuckles bled constantly due to extremely dry and cracked skin. Instagram-ready, I was not. There is a line between rendering a complex subject filmable and sexing-up a serious illness, and To the Bone crosses it from the first scene. And when all a movie about anorexia tells you is that people with anorexia have issues with food, and that this makes them thin and unhappy, you have to wonder what the point of the movie is.

Anorexia’s physical manifestations distract even those of us who have suffered from it from grasping the internal issues. Indeed, that is the point of the starving: we don’t have to think about the unhappiness that led us to this point. In one interview, Noxon said that being around Collins and the other actors who were losing weight was difficult for her. “I started to need to turn to the other female producers quite frequently and say: ‘I’m going to need you to tell me that I don’t need to lose weight,’” she said. When there is a part of you that still gets turned on by not eating, you will not be able to discuss anorexia properly, because you are still preoccupied by the surface symptoms.

Even beyond the director’s own issues, it feels almost inevitable that anorexia should be glamorised in a movie made today. We have come a long way from 1983, when Karen Carpenter died of anorexia and people were shocked that someone could actually starve themselves to death, but despite the increased awareness, conversations about the illness still too often descend into voyeuristic fascination. Since the 90s, when skinny became the female beauty standard (a sharp diminution from the more Amazonian supermodels of the 80s), representations of anorexia in mass culture have come wrapped in a weird mix of prurience, spectacle and aspiration. A woman in the Mail stable for a long time has written in a wildly irresponsible way about her anorexia. The glamorisation of anorexia online is notorious by now, with the rise of “pro ana” (pro anorexia) websites, which pass on tips about how to avoid eating, and “thinspo” (thin inspiration) images on Instagram; anorexia has been reduced to an aesthetic expression and To the Bone reflects that.

In terms of art, there is remarkably little that is much better. Poor Richey Edwards, the late guitarist from the Manic Street Preachers, wrote probably the most brutally evocative song about it, 4st 7lbs (“I eat too much to die / And not enough to stay alive / I’m sitting in the middle waiting”). But he himself was so caught up in the illness he could only depict the immediate experience, not the larger overview. In books, there are plenty of anorexia memoirs now – both celebrity and non – most of which, to be honest, are little more than a mix of food diaries, pop-psychology and self-help.

By far, the best book on the subject is Jenefer Shute’s astonishing novel Life-Size, which captures the confusing early descent into the illness, the loneliness of it at its most extreme and the weirdness of hospitalisation better than anything I have ever seen or read. Noxon has responded to criticism of her movie by emphasising it is based on her indidvidual experience, but Life-Size reveals the laziness of this popular get-out clause. Everything is an individual experience, but if your re-telling of it strikes no general chord, the fault is in your telling. Life-Size is a deeply personal story, about a twentysomething with anorexia called Josie. But in its wholly original, quasi-poetic prose style that shifts between memory, the hospitalised present and Josie’s hallucinations, this is a book that eschews the cliches and, in doing so, touches a wider truth. No one thing can cure someone with anorexia and this book definitely didn’t cure me. But it did help me get a fix on my own experience as I was finally starting to recover and, in that regard, changed my life.

There have been only two good movies about anorexia: both treat the subject almost metaphorically and both were directed by Todd Haynes. Most obviously, there is Superstar: The Karen Carpenter Story, Haynes’s film about the most famous anorexia sufferer of all, retold with modified Barbie dolls, which perfectly captures the artificially perfect world that many with anorexia feel they need to embody. Then there is his 1995 film Safe, about a woman who seals herself off away into an antiseptic world. While not explicitly about anorexia, Safe evokes the real experience of the illness: the self-imprisonment, the illogicality, the sense you are being eaten up from within by forces you cannot control.

When I think back on my years of being ill, which went on long after I left hospital, I barely think about the food and the weight at all. Instead, I remember the cold, the isolation, the institutionalisation, the time lost and all the things Haynes’s movies and Shute’s book depict so well. Keanu was right: it’s not about the food. That’s just the boring stuff that distracts even those who should know better.

To the Bone streams on Netflix from Friday.

• This article was amended on 13 July 2017 to clarify that a writer’s work had over time appeared in the Mail stable, not just in one title within that stable.