Some years ago, I earned a low-calorie crust by writing horoscopes for a well-known diet magazine, and developed a lasting fascination with the language of diet literature. I particularly liked the Success Stories, in which readers who had shed a little lard were slathered in make-up, shoehorned into slightly smaller tents and photographed through a thick filter. These inspiring people were interviewed about their struggles with the fat-monster, and their stories usually contained the words, “Chips were my downfall.”

The absurd grandeur of the word “downfall” in conjunction with “chips” gave me a vital clue to what my customers needed. I was not allowed to mention weight loss or dieting directly (search me why), but I could slip in words such as “downfall”, “battle” and “victory”, and everyone would know that I meant the same thing.

“Prepare for a betrayal around the middle of the month,” I would write, “when a close friend or loved one fatally undermines your resolve.” Traditionally, if you wanted to use sonorous language of that kind, you had to be either a great 17th-century dramatist or a fairground fortune-teller. Nowadays, the big verbal guns are deployed to express the modern tragedy of being fat — not that anyone is crude enough actually to mention the word.

All diet books follow certain rules. A good diet book must contain pages of pseudo-scientific waffle to convey a “plan” that could easily be expressed in a single sentence. It must also contain lots of meal plans and strangely inedible recipes. It will often contain personal accounts, which begin with getting stuck in a turnstile and end with the ceremonial wearing of a bikini. These dreary adipose layers of prose are necessary, to bulk out the basic truth that you will get thinner only if you eat less.

The Shangri-La Diet (Hodder Mobius £12.99) is one of those wacky, novelty, good-gracious, miracle diets. Seth Roberts, a professor of psychology, discovered a link between the flavour of a food and the amount of calories therein. I’m going to give away the secret, so if you want to buy the book, look away now — you have to drink either plain, sugared water or flavourless olive oil an hour before a meal. This will dramatically reduce your appetite: chips will no longer be your downfall, and the pounds will just melt away.

How the Rich Get Thin (Headline £12.99) is not for those seeking miracles. Jana Klauer, “Park Avenue’s Top Diet Doctor”, knows that achievement comes only through hard graft. The rich, it turns out, get thin in exactly the same way as everyone else, but Dr Klauer adds a few tips tailored to the wealthy — if someone sends you a complimentary muffin basket, give it to your doorman, and so forth. This is a perfectly reasonable weight-loss regime in an extremely vulgar package.

A more pleasurable approach can be found in Roger Corder’s The Wine Diet (Sphere £9.99), which urges us to drink red wine every day and enjoy the numerous health benefits of nuts and chocolate. There’s a lot of serious scientific stuff here, but this book is about nutrition and lifestyle rather than simple lard loss. Corder’s advice is grounded in hard facts, and perfectly sensible.

Subtitled Sleep Yourself Slim, Jane Worthington’s The Duvet Diet (Rodale £9.99) wraps its meal plans and anecdotes in the beguiling idea that you can aid weight loss by getting more sleep. “By losing out on zzzs, you could be failing to provide your metabolism with a winning edge.” There’s a lot about sleep patterns and hormonal changes, and complicated lists of “Power Nips” and “Half Nips”, the usual dismal snacks involving oatcakes.

In the Land of the Rising Sun, only professional sumo wrestlers get fat. Naomi Moriyama and William Doyle’s The Japan Diet (Vermilion £6.99) is, therefore, self-explanatory — a food regime based on fish, rice and fresh veg, attractively packaged in a bento box. The dieting advice is the same old stuff (eat less, move more), but the recipes look quite appetising, even if the authors include too much processed food in their meal plans.

Who ever kept to a meal plan, anyway? Do people honestly weigh out 4oz cottage cheese and two slices of skinless chicken breast? And what is a “handful”, as in “a handful of steamed cauliflower”? The lists of punitive, hair-shirt recipes in all these books would worry me if I thought anyone took a blind bit of notice. No wonder people “backslide”, despite the helpful tips for overcoming temptation, such as going for a brisk walk or heaving a bit of coal until the craving dies.

Rosemary Conley’s language is positively belligerent: “I challenge you to find another diet that will enable you to lose weight faster or more healthily than this one!” Britain’s most assiduous and noisy diet guru is shown on the cover of her Ultimate GI Jeans Diet (Arrow £6.99) wearing hideous jeans, terrible pointed shoes and a skimpy yellow vest that looks weird with the Mrs Thatcher hair. Her advice is basic and bracing, but the book does seem to have been written with silly people in mind, since it’s mostly a brisk reheating of the Bleeding Obvious.

Yet further down the diet-book food chain are Rick Gallop’s Express GI Diet for Busy People (Virgin £10.99) and Ian Marber’s The Food Doctor Diet Club (Dorling Kindersley £14.99) — brightly coloured corporate packages for fat people who are scared of anything that looks too much like a book. Marber’s has some particularly choice success stories, unfortunately without the traditional “before” pictures.

If you are thinking of going on a diet, don’t bother with books like these. Who are you kidding? You know they’ll end up in the spare bedroom. The heroine of Muriel Spark’s novel A Far Cry from Kensington loses weight by eating exactly half her normal amount of food. That is surely all you need to know about becoming less fat.

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