Those of you dieting your way to a svelte physique amid the flesh-exposing terrors of summer should take courage from Mrs Hawkins, the heroine of Muriel Spark’s wonderful novel A Far Cry from Kensington.

Mrs Hawkins, with her unfortunate ‘Rubens quality of flesh’, only starts to worry about her weight when she gets a new job and notices that all her colleagues suffer from some kind of affliction. These range from stammers to stomach ulcers, pock-marked faces to war-wounds, and so, lying awake one night, she wonders what her own ailment might be. She gets out of bed to look at herself in the mirror: ‘I stood there, massive in my loose, warm nightdress.’ Then she realises, ‘I was immensely too fat. I was -overweight, I thought, to the point that anyone employing me must be kinky.’

Mrs Hawkins decides to slim down, even though she risks losing her job along with the weight. This is 1954 — long before the 5:2, Dukan or even Weight Watchers — so she follows a diet of her own invention: ‘You eat and drink the same as always, only half.’

More feeble dieters might quail at the thought of halving their food over a prolonged period, but Mrs Hawkins rather enjoys it. ‘I sneaked a glance at the amount everyone else was eating. It seemed enormous in relation to my half,’ she gloats during a smart dinner party, to which she wears an old evening dress, the waist joyfully taken in ‘a good inch to both sides’. For sure, Mrs Hawkins suffers from pangs, but she is made of stronger stuff, and stoically reflects on her constant weariness and hunger: ‘I took pride in that.’

The ‘eat half’ diet gets results, leaving our heroine so slim and spritely that the other characters start to address her by her first name, Nancy, instead of the matronly ‘Mrs Hawkins’. All is rosy, until a surprising, sinister side to this dramatic weight-loss comes to light.

Hector Bartlett, an aspiring writer and annoying hanger-on, has despised Mrs Hawkins ever since she called him a pisseur de copie — an apt insult for this horrible hack of a man. It eventually transpires that Hector takes revenge on Mrs Hawkins by coercing her neighbour Wanda, a Polish dressmaker, to ‘treat’ her with the mysterious pseudoscience of radionics. Poor Wanda, terrified by Hector’s devious threats, feebly follows his instructions. She snips off a lock of Mrs Hawkins’ hair while altering her dress and uses ‘the Box’ on it to change her energy. When Mrs Hawkins starts to lose weight, Hector credits this black magic.

Indeed, he even makes her an unwitting case study in his chilling paper ‘Radionics A Power Against Evil’, in which he states: ‘within a few months of treatment, the evil victim, an extraordinarily obese woman, began to waste away and was unable to hold down a job.’ How galling for Mrs Hawkins to lose so much weight only to have her arch-nemesis pass it off as his own work!

I wish you well on your summer diet, and hope you find inspiration in Mrs Hawkins’s steely determination, but not in her silence. Her one mistake was to tell no one — other than the reader — about her ‘eat half’ diet, preferring just to get on with it. Instead, I advise you to tell everyone about your tough slimming regime and make them take note of your astonishing determination and willpower. Losing weight is very hard work and no one should be able to pass it off as something so easy and painless as magic.