Before you rush to take offence, let me make one thing clear. I am not a starver, or a dieter, or the kind of mean-spirited creature who looks at other women's thighs and thinks: they could use some work. I am a greedy person, a keen consumer of all things meat and dairy. I am also a lumpy person. When I wear low-cut jeans, a ripe Brie-like swell of flesh rises and falls above my waistband. You are as likely to see me in a miniskirt as you are the Duchess of Cornwall in full bondage gear. Does this worry me? Not much. There are times when I'd like to be more taut. Mostly, though, I accept this soft veil of fat, the one the Victorians liked to call their "silken layer". It is what makes me a woman. No point in shirking that.
Still, I would hate to be overweight. Obesity is disgusting, and with each year that passes, it becomes more acceptable to state this fact. The days when one avoided mentioning portion control to teenagers for fear that they might fall prey to anorexia are long gone. It is clear that an acute remark, the passing on of a sense of control, do not in themselves set a girl on a path to starvation. But the failure to pass on a sense of control may have severe consequences. The developed world is morbidly fat; if we carry on like this increasing numbers of us will die young. It is also unhappily fat. I have yet to meet that figment of the popular imagination, the jolly fat person. Watch an obese woman struggle on to a bus, and all you see is misery.
Perhaps I was crotchety, having eaten far too much over Christmas, but there were moments when this book made me so mad I could scarcely breathe. Wendy Shanker is a New Yorker who has tried just about everything to lose weight, including spending $9,430 at a place called the Duke Diet and Fitness Centre where, over four weeks, she managed to shed no less than two pounds. After this experience, she decided that she'd had enough. She would embrace her great girth. Down with dieting! Having released herself from the tyranny of the protein shake, she then decided to help others do the same. The result is this muddle-headed, self-deceiving, whiny book.
Shanker's central thesis is: a) that it is possible to be a healthy fat person and b) that as 68 per cent of American women are now a British size 16 or larger, it is the medical definitions of obesity that should be adjusted rather than people's lifestyles. I hardly need spell out what rubbish this is. The healthy overweight are extremely rare; most fat people have knees that ache, and clogged arteries, and overworked hearts. Diabetes is their destiny. How do you think they got fat in the first place? Not by running marathons. As for the idea that we start thinking of big as normal, well, all sorts of things are "normal"; in Baghdad, kidnapping is now a way of life.
Shanker's book, like her weight, is a product of 21st-century decadence. Naturally, she cannot construct an argument; her thinking is as skewed as the crazily illogical diets - gallon of Tasti D-Lite, anyone? - to which she used to be enslaved. Thin people are envious of fat people, she argues, because fat folk allow themselves to eat what they want. I don't think so. Thin people are scared of fat people (they stand as a warning); they sometimes find them comforting (she's fatter than me). But envious? Worse, even as Shanker rejects body fascism, she embraces it. She favours control underwear, the kind that allows you neither to bend over nor to pee. "But hot damn," she writes. "I looked so fierce." So what is her point? That it is unfair to expect women to be skinny? Or that skinny is fine so long as you don't have to give up French toast to achieve it?
The Fat Girl's Guide poses as brave, but in fact it is lily-livered, always shying away from tricky words such as "glutton" and "greed" (words that carry biblical weight, that suggest some measure of personal responsibility), always looking for someone to blame (parents, cele-brities, doctors). When I was a girl, my grandmother would decline second helpings with the words: "I've had sufficient, thank you." I used to think this funny and old-fashioned, but now I wonder at her accuracy, physical and moral. While half the world starves, the rest of us scoff egg-white omelettes and wonder if, because we've gone without yolks, we can have fries, too. We still understand - just - the word "full", but "sufficient", as this terrible book only serves to remind, has all but disappeared from the lexicon.
Rachel Cooke writes for the Observer