Catcher in the Wry : WHAT’S EATING GILBERT GRAPE<i> By Peter Hedges (Poseidon Press: $20; 335 pp.) </i>

Gilbert Grape, the narrator of Peter Hedges’ occasionally funny but flat first novel, lives the life of a discontented 24-year-old in the tiny town of Endora, Iowa, population 1,091. “Describing this place is like dancing to no music. It’s a town. Farmers. Town Square. Old movie theatre closed down so (now) we have to drive sixteen miles. There were twenty-three in my graduating class and only four are left.”

Gilbert works in the evaporating downtown’s one underpatronized and far-from-super market while he tries to figure out what it all means. He waffles perpetually between rejection of the phony adult world and the desire to hit the road and see more of it.

His Holden Caulfielditis takes the form of refusing to visit Food Land, the new supermarket on the town’s outskirts with its long, insincere food-conveyor belts, flashy lobster tank and soothing Muzak, and feverishly disliking Lance Dodge, a classmate and fake who’s making good as a talking head on the Des Moines TV news.

If Gilbert is discontent, his family goes a long way to explain why. Among the crew is a sister, a stewardess who treats the family to safety-feature- demonstration pantomimes when she’s home.

Then there’s Mom: “It’s time for you to know the rarely spoken truth about my mother, Bonnie Grape. y mother’s a porker. She started eating to excess the day our dad was found dead seventeen years ago. Since that day, she’s been going at it nonstop . . . . (Now) no household scale goes high enough. It’s been three years since she stepped out of the house.” That’ll teach her husband to hang himself without so much as a note.

Her weekly grocery order overflows Gilbert’s pick-up truck, and secretly the children have been shoring up the floor beneath where she reclines to head off a stave-in.

With all this eccentricity afoot and a strong narrative voice, Hedges has a shot at a funny, dark Midwestern Gothic novel, but he has little luck putting his characters in motion. Unfortunately, Gilbert’s bald, first-person present-tense adolescent voice displays little range and can’t soften caricature with emotion. Each member of the family--and the town--is so unsympathetic, distinctive and odd, it’s impossible for the reader to imagine them in three dimensions. How can there be a personal voyage of discovery and change when everyone begins so far off the map?

Gilbert, a bit too juvenile to make a credible 24-year-old, is partly redeemed by the care he takes of Arnie, his mentally impaired younger brother. In Hedges’ most effective scenes, Arnie’s childlike love for Gilbert holds him in Endora. Every morning there’s Arnie waiting to go for a ride on the horsies at the county fair or play hide-and-seek.

To break the plot logjam, Hedges mints Gilbert a girlfriend who has just moved into town. Comically saintly and out of tune with the town’s only appealing quality--its incompetence and lassitude--Becky’s tricks include holding a mirror up to Gilbert’s face to show him how self-loathing has disfigured it, and scribbling “It’s the insides that count” where Gilbert will see it. Sex, very much on Grape’s mind, is not on her agenda.

The coup de theatre that ends the book follows Arnie’s 18th birthday. Mrs. Grape finally succeeds in joining her husband and the majority, but she is too fat to be carried down the stairs to the hearse. So the children decide to turn the whole house into a funeral pyre with her in it.

The reader only wishes Becky would top things off with an auto-da-fe and leave Gilbert and simple, affectionate Arnie to their merry-go-round.