BOOK REVIEW / A poor thinner: Life-size - Jenefer Shute: Secker & Warburg, pounds 7.99

THIS NOVEL is prefaced with a passage from A Brief History of Time, about the possibility that stars may have to shed mass in order to avoid becoming catastrophically smaller. Anorexics operate on similar principles, and their condition is frequently an inverse form of stardom too. They turn heads in the street, they are surrounded by attendants when hospitalised, and their self-absorption makes Madonna look like Chaucer's Grisilde.

They provoke strong feelings in others: bafflement, or hostility. An individual becomes known to those around her as 'an anorexic' after being diagnosed thus by medical professionals. Anorexia merely means loss of appetite; by limiting the concept to its most extreme cases, the possibility that it exists as a continuum is obscured - to the relief of those who fear discovering it in themselves.

Quite a few potential readers, therefore, will give Jenefer Shute's novel a wide berth when they learn that it is extensively devoted to descriptions of her anorexic narrator's loathing for food. Everybody knows the feeling. Indeed, after a few chapters, any act of food consumption begins to seem like a tightrope walk over an abyss of nausea. Nor will the waverers' doubts be assuaged by a synopsis of the narrative. A 25-year-old woman is the site of a struggle to increase her weight from 60lbs to a point where she can leave the nursing home.

The faint-hearts will miss a mordantly funny novel, though. In addition to its beady-eyed wit, Life-Size offers vital insight, stark and even lyrical by turns, into how anorexia looks from the inside. As a first novel, it is a virtuoso performance. Based on feminist analyses of the condition, as deriving from the tyranny of body images, its translation of theory into character is a notable achievement.

The key to its success is that Jenefer Shute understands the importance of language in the strategies of the anorexic, and turns it to literary advantage. Josie, the narrator, is engaged in a resistance that depends as much on her representation of the struggle as on her refusal to eat. She eulogises her fleshless form, and reviles any treacherous zones where fat tends to accumulate.

The institution solicits information through diagnostic questionnaires. Josie declines to answer, or mocks: 'Ideal Weight: Zero G'. It is revealed as an ideological struggle. The institution's staff occupy the high ground of medical authority and common sense, whereas Josie's rhetoric is peppered with the slogans of Western body politics - 'Make your scale your best friend and your lover'. She forces her belief system to pathological extremes: at school lunchtimes, she recalls, her will-power became a party piece.

The deep roots of her condition remain indeterminate. She has power as a narrator, but not authority - after all, she is unable to judge the fundamental question of how much space she occupies. Was her father's drunken stumble into her bedroom an attempt at sexual abuse, or just a clumsy show of affection? The narrative is all the stronger for such ambiguity. Its only weakness is that, being entirely in the first person, it is unable to explore the manipulativeness that goes with the condition. In Josie's perfect solipsism, the identities of others are vestigial - unlike their images. Her most visceral loathing is for her mother, 'her squat frame hauling its huge belly and behind around like a life sentence'. Perfection, as Josie sees it, is what her mother is not.