CYNTHIA WINE has been working as a hired gut for 20 years. Asa restaurant critic and food columnist she`s been part of a Curious Culturalrevolution - as we`ve become obsessed with the health and weight of our bodieswe`ve also become giddily infatuated with the foods we put in them Wine describes Eating for a Living: Notes from a Professional Diner (Viking, 306 pages, $24.99 cloth) as "dispatches from the front lines of the foodrevolution." These dispatches are more about fads and passing fashions infood than they are about gustatory sensations Perhaps it`s impossible to write at length about foodwithout being so selfindulgent that the reader loses all appetite. Certaintythis book is a long series of bites and not very filling. The best bits are devoted to the businessof simply being in restaurants and the rituals associated with dining out.There`s a fine and memorable chapter about the phenomenon of the business lunchbeing used as a cover for dating. I seems that in these tense times, men andwomen invite each other to lunch in order to linger over food and feigninterest in the typical topics of a business lunch. What they`re really doingis having a romantic interlude without ever admitting it. There is a hilarious chapter on the joyof processed food, and sections that offer some basic, sensible advice abouteating out - how to deal with bad meals, bad service, and snooty servers. Winealso muses about the rise of the celebrity chef and clearly has little patiencewith their egos and overpriced eateries. Still, Eating for a Living isn`t abook with real guts there`s too much ambivalence about the food business. It`sa book to dip into and then push away, like a mediocre meal.