We humans are a sucker for a journey. The tears I’ve shed watching a rural teenager get over the death of her grandmother through the healing properties of singing Whitney to Simon Cowell. The number of warm summer evenings I’ve lost because I had to wait through two ad breaks to find out what this ex-teacher from Ottowa looked like after she’d got rid of her baby weight; her baby now a teenager, the weight to lose that of a fully dressed four-year-old. A beginning: fat. A middle: hard work, a little crisis. An end: thin.

But, this week, Weight Watchers is acknowledging that, while this story is satisfying for the armchair viewer, it is not realistic. Not for the thousands of people for whom the journey of weight loss looks less like a simple car ride and more like a kind of nightmarish Interrailing experiment where your wallet is nicked by a one night stand you were falling in love with and your bag gets lost at the airport, containing your contact lenses and inhaler, and then suddenly the island you came from goes missing in a storm. Weight Watchers is scrapping its “before and after” photographs, the ones that show the transformation of their members Benjamin Button-ed, growing down, from big to little.

“We’re not going to discourage a member who wants to show where they are today versus where they started,” a spokesperson explained, “but when they’re talking about their journey, we want to celebrate all their moments. As a brand, we want to be your partner no matter at what point you are.”

When I went to an inquiry by the all-party parliamentary group on body image in 2012, Susie Orbach gave evidence to the assembled MPs alongside spokespeople for weight loss companies. Later, Orbach pointed out that she could smell the nervousness on their breaths, she wrinkled her nose, “a sourness”. She thought they must be feeling guilty, touting expensive promises that would never come true for people desperate enough to buy them. Because it is documented now that diets don’t always work in the long term. In Weight Watchers’ own studies, the average person will reduce their body weight by around 5% after six months, but within two years a third of that will return. Studies begat studies. One suggested that losing and then gaining and then losing weight, that terribly feminine tradition, caused long-term damage to the metabolism. Another concluded that once your body reaches a certain weight, it’s almost impossible to exist at a lower weight for long.

We should probably offer some limp applause to Weight Watchers for its attempt to adapt to 2018 and its associated traumas, but really all they and their fellow companies in that industry of loss are doing is trying to reposition themselves to stay relevant. Luckily for them, the thing they’re selling still stays in fashion. Everybody wants to be thin.

You can call it whatever you like: strong, healthy, fit, toned. But at its end it is thin. It is thin, it is smaller, it is a body that is less than it was before. And while diets were once a thing to be stoically dealt with in the privacy of one’s kitchen – a spoonful of cottage cheese, celery with its smear of peanut butter, cereal for lunch – these new words have pushed diets public, on to Instagram, where an aspirational body is one that not only fits into sample sizes but also documents every rainbow salad it digests. Here is where the before and after pictures really live, on accounts that are thirsty for likes, that contribute to the idea that bodies are plasticine, and with discipline can be remoulded, regularly.

The attraction of Weight Watchers for many was the way it repackaged food to remove the fear we privileged masses had attached to it. It exists in neat portions, it isn’t pudding but “points”. Because food for many who want to be thinner is terrifying and insane, a thing that will attack you in your sleep.

And while Weight Watchers helped dieters navigate that with those pairs of photos, some people no longer want its help – they have the whole world. Social media is the place where we compare our lives and bodies to those of strangers, picking through our insecurities like broken glass. People post their own befores and afters in a haze of hungry desperation – we can’t see ourselves unless we look through someone else’s eyes. The weight loss journeys are satisfying but false, as there’s no after. There’s always only now, isn’t there? Like some terrible quote somebody would have tattooed on their shoulder in Latin, there’s always just struggle and fear, and moments of elation, and the cruel crawl between wanting to be thin and wanting not to care. And you can’t really capture that in a photo.

Email Eva at e.wiseman@observer.co.uk or follow her on Twitter @EvaWiseman