Big Brother, By Lionel Shriver

A razor-sharp novel with an unreliable narrator is hampered by its tight authorial grip

Dysfunction and dystopia: Lionel Shriver (Getty Images)

Lionel Shriver has written 11 novels, one of which made her famous (We Need to Talk about Kevin). We know her sort of subject – psychopathology, population control, the US healthcare system – and the razor wit she turns on them. This, her twelfth, is a classic of the Shriver genre.

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Big Brother is about obesity. It is the story of a dysfunctional American family: the middle-aged children of Travis Appaloosa (not his real name), the passé star of a once-famous TV serial called Joint Custody, also about a dysfunctional American family. Pandora, our narrator, is the middle daughter, peacemaker and general good girl; the big brother of the title is Edison (already ex-) jazz star and general bad boy. There is also a younger sister, Solstice; but the two elder siblings banded so closely together to survive their childhood that they excluded her, and she remains excluded from their adult lives.

Shriver is wonderful at the things she is always wonderful at. Pace and plot, for instance: she draws us, unsuspecting, into the shock of Pandora's meeting with Edison after a break of four years, during which he has ballooned from the hip idol of her youth to a "fairground float" of 386 pounds; and thus she charts the ghastly, comic ups-and-downs of his year-long diet, masterminded by her, and its ghastly, comic aftermath.

Psychology: she is alarmingly accurate about the Western obsession with weight, crazy diets, food in general; about people's disgust at the morbidly obese. Finally, character, in grotesque Dickensian mode: Edison himself, slob, fame addict and control freak; Pandora's husband Fletcher, grim health-and-hygiene fascist, who pocks his dental floss in bedtime conversation, but has (probably) a heart of gold.

But Big Brother is also annoying. First, those names. Apart from Pandora, Edison and Solstice, there are Fletcher's kids, Tanner and Cody; Pandora doesn't use Appaloosa, as Edison does, but Halfdanarson, which is Swedish, but just as odd. Even Pandora's best friend is called Oliver Allbless. Is this to do with the fake reality of American TV? I thought so; until I remembered some of Shriver's other heroines – Corlis, for instance, and Estrin. No: I think it's just a tic, or perhaps a self-reference to the girl who called herself Lionel.

More important is something I'd better put carefully. Shriver likes literary experiment. The Post-Birthday World played with alternative realities, and Kevin itself was an epistolary novel, with a not-altogether reliable narrator. Pandora is an unreliable narrator too; more, she is sometimes a misleading one. This is cleverly handled, but self-defeating. Shriver has the precious gift, for a novelist, of telling a good story. If it turns out that the story may not be the one we thought it was, our insights crumble into dust, and we wonder why we bothered.

This is a novel about control. Edison and Fletcher try to control Pandora, and Pandora tries to control them. Sometimes she seems to be aware of this; sometimes she doesn't. If that were all, she could be a complex creation, like Eva in Kevin; and one of the themes of Big Brother might be that we can never know ourselves, as it is one of Kevin's.

But the biggest act of control in this novel is the one Shriver perpetrates on the reader. The great unreliable narrators of fiction – Dowell in Ford's The Good Soldier, for instance, or Maisie in James's What Maisie Knew – know less than the reader, not more. A writer who shows her power over her readers is in danger of losing them. It was a great ride; but in the end, I'm afraid, this one lost me.