‘It can be hard to say goodbye to bad habits like eating!”; “90% of our clients say stress makes them binge. And loneliness. But everybody’s lonely, gosh!”; “I think you’re gonna do great and have a lot of loose skin!” Thus speaks, in relentlessly upbeat tones, Plum Kettle’s slimming-class teacher to her shy, uncertain, morbidly obese client, who is saving up for gastric band surgery, so that she can be reborn as “your thin person within!” and start her life anew. Or rather – since she has been overweight and condemned for it since childhood – for the first time.

Plum’s life experiences as a fat woman, living in a world in which eating is the enemy, loneliness is no excuse and the knock-on effects of gastric band surgery are the greatest joys you can hope for, are at the heart of Dietland (Amazon Prime), an adaptation by Marti Noxon of Sarai Walker’s 2015 novel. The book follows Plum, cowed and isolated by her physical appearance and dreaming of the day that surgery will take care of all her problems, in her work as an advice column ghostwriter for Kitty Montgomery, the editor of a girls’ fashion magazine. This relatively innocuous setup quickly darkens as Plum finds herself stalked by a mysterious goth girl who leaves her a book called Dietland, about the founder of the Baptist Diet Plan she followed – religiously – until she left college and became embroiled in a feminist cabal that has infiltrated Kitty’s empire. Meanwhile, someone calling herself “Jennifer” is on a murder spree, killing men who have walked free after being tried for crimes such as the rape of a 14-year-old-girl who then killed herself. Another victim is a photographer known to have a penchant for young models.

Julianna Margulies as Kitty and Joy Nash as Plum in Dietland. Photograph: Patrick Harbron/AMC/Amazon

The rollicking plot, along with Walker’s scabrous satirisation of the beauty industry and the deep-seated self-loathing it breeds, made Dietland a bestseller at the time. But it is now – in the #MeToo era and in the wake of revelations about male depravities and depredations against less powerful women, and the ongoing shift towards body positivity and the dismantling of narrow beauty ideals – that the book’s time has truly come.

Noxon’s adaptation keeps all that was true, good, funny and necessary about the book – including its aggression not blunted but made palatable by humour of the blackest sort – and added more. Like Reese Witherspoon’s development of Liane Moriarty’s Big Little Lies, it is pro-women to its bones and infused with sure and certain knowledge about female life. It is another programme that makes you realise how much of what we watch about ourselves and what it is like to move through our world is made up of guesswork, approximation and simple wish-fulfilment by those who have no real knowledge of or interest in its accurate depiction. But every woman will flinch in recognition and feel a slight panic at the casual disrespect and the active harassment of Plum as she walks down the street. Whether you are judged desirable or undesirable, the effect is the same. The clicking sound the men make to get her to turn their way so they can humiliate her further is literally pitch perfect.

By the end of the first episode, Plum – masterfully played by Joy Nash in her first lead TV role – has met Julia, the woman who heads the beauty department at the magazine as a cover for her mission to bring down the industry from within, and has been inducted into the resistance (although she may not fully realise it yet). Leeta, her “stalker”, introduces her to the author of Dietland, Verena, who invites her to be part of the collection of confident, supportive misfits at her home and societal-deprogramming centre, Calliope House. Confronted suddenly with examples of other ways of being, Plum is jolted if not out of her discomfort then at least into a new, refreshing kind.

All the changes to the book so far have been sensible and superficial: TV Plum interacts more with others than book Plum and Kitty’s part has been beefed up – a cipher in the book, she is now played with perfectly coiffed, ever-smiling venom by Julianna Margulies to personalise an otherwise-too-abstract fight against collective norms – and disparate narrative strands have been more smoothly interwoven. All in all, a delicious, satisfying and moreish meal. One to binge on and not feel a moment’s guilt about.