Life in the fat lane.

As a nutritionist, I see fast-food restaurants as minefields of hidden grease and salt. Only on the road with the kids do I appreciate their true value: clean bathrooms.

Once in a while, though, almost everyone gets stuck in one: to fortify yourself for the other half of the mall, to restore your sanity when you're only averaging 35 mph on the New Jersey Turnpike, or to let the kids run loose ("pretend they're not ours").

Recent tests sponsored by CSPI indicate that you can dodge some of the fastfood fat by doing a little "waste-removal."

For example, we bought some Original Recipe Kentucky Fried Chicken, peeled off most of the breading and skin, and sent it to a lab for analysis. That cut the calories in half and the fat by two-thirds. The remaining chicken meat was fairly lean, even though (to be realistic) we had it tested with bits of breading and skin

Next, we bought a Pizza Hut HandTossed Cheese Pizza, and had it analyzed after we removed the cheese. Out went 40 percent of the calories and 85 percent of the fat, much of it highly saturated butterfat. (With the cheese, two slices of medium pizza supply nearly two-thirds of the saturated fat the average person should eat in an entire day.) The only disadvantage: most of the calcium also was lost.

Pizza without the cheese may sound like a sandwich without the filling, but a good crisp crust topped with tomato sauce, green pepper, mushrooms, and onions can be scrumptious. In fact, cheeseless pizzas grace many restaurant menus in Italy.

The next time you end up in restaurant, use this survival guide, which we pulled together from manufacturers' nutrient data. And don't be surprised if wasteremoval eventually leads to waist-removal.

MCDONALD'S * Order a McD.L.T. without the mayo and you strip away 135 calories and 15 grams of fat. That's more fat than you'd get in a small order of French Fries. * Wipe the Tartar Sauce off your Filet-OFish, and you save a third of the calories and almost two-thirds of the fat. The sauceless sandwich has no more fat than a regular Hamburger (10 grams). * Pick a packet of Lite Vinaigrette and forget the Thousand Island, Bleu Cheese, Ranch, or Peppercorn Dressing. You'll save 32 to 42 grams of fat-roughly a day's fat allowance for an average eater. * Don't open those handy packets of Croutons or Chow Mein Noodles and save about 50 calories each. n More than a third of the calories and twothirds of the fat in an order of Hotcakes come from the syrup and butter. Go easy on both. * You can eat two fat-free Apple Bran Muffins and still get fewer calories than you'd get in one Apple, Iced Cheese, Raspberry, or Cinnamon Raisin Danish. You'll also save 16 to 22 grams of fat. * You can eat two bowls of Wheaties with milk and get 30 percent fewer calories and 70 percent less fat than if you eat one Sausage McMuffin.

Best Bites:

Hamburger, Apple Bran Muffin, Frozen Yogurt, Cheerios, Wheaties, Orange Sorbet, Chunky Chicken or Side Salad with Lite Vinaigrette or ReducedCalorie French Dressing, English Muffin, Filet-O-Fish without Tartar Sauce, Low-Fat Shake. * Have a Whopper "your way' mayo), and you'll save about 150 calories and more fat (16 grams) than you'd get in a cup of ice cream. * Order your BK Broiler without the sauce. That removes 90 calories and more than half the fat from this great-tasting chicken sandwich. * Top your salad with Light Italian instead of the other dressings and you'll save 2 1 0 to 270 calories per packet. That's almost as much as in an entire Lean Cuisine entree. * Hold the mayo on the Chicken Specialty Sandwich and cut 200 calories and half the fat. * A Bagel with Cream Cheese has as much fat as a Bagel with Ham, Egg, and Cheese. Order the Plain Bagel instead of the Cream Cheese and save 100 calories and 10 grams of fat. * If you can't do without meat on your Croissan'wich or Bagel, at least steer clear of the sausage. It has almost twice as much grease as the ham or bacon. * Choose a Croissant over a Biscuit, and a Bagel over a Croissant. Even plain, a Biscuit has 17 grams of fat, more than 300 calories, and more than 750 mg of sodium. * Dip your Tenders in Barbecue, Honey, or Sweet & Sour Sauce instead of Ranch or Tartar, and save 18 grams of fat-more than you'd get in an order of Onion Rings.

Best Bites: BK Broiler without sauce, Chicken Tenders regular Hamburger, Plain Bagel, Salads with Light Italian Dressing. * The shell under a Taco Salad doubles the fat (to 61 grams) and the calories (to 941). Even without it, the salad has more fat than a McDonald's Quarter Pounder with Cheese. * You could eat two orders of Chicken Fajitas and still get no more calories or fat than if you ate one Double Beef Supreme Burrito. * A Bean Burrito has as many calories as a serving of Nachos, but only half the fat and saturated fat. * It would take three servings of Pintos & Cheese to give you about the same calories and fat as a single Mexican Pizza.

Best Bites: Bean Burrito, Pintos & Cheese, Chicken Fajita, Steak Fajita, Taco, Soft Chicken Taco. PIZZA HUT * If you just can't bring yourself to skip all the cheese, ask for cheese on only half your pizza. * Ask for a Hand- Tossed Pepperoni Pizza without the pepperoni. it's made with only about half as much cheese as a HandTossed Cheese Pizza. You could also ask for a Cheese Pizza with half the cheese.)

Best Bites: Cheese-less (or half-cheese) pizza with lots of vegetables. BASKIN-ROBBINS * A Waffle Cone has twice as many calories as a Sugar Cone. * You could eat two scoops of Red Raspberry Sorbet or Daiquiri Ice and get no more calories than if you ate one scoop of French Vanilla or Pralines 'n Cream Ice Cream. You'd also save 14 to 18 grams of artery-clogging fat. * If you're stuck on ice cream, Rocky Road and Chocolate Raspberry Truffle have the most calories; Very Berry Strawberry and Vanilla have the fewest.

Best Bites: Daiquiri Ice, Sorbet, Sherbet, Nonfat Frozen Yogurt. KENTUCKY FRIED CHICKEN * Make a "Two-Piece Dinner" out of two pieces of Corn on the Cob and one piece of Chicken. * The meat on Thighs and Wings is fattiest, Drumsticks and Side Breasts are in the middle, and Center Breast is leanest. (But a Drumstick has the least amount of fat because it's the smallest piece.) * If you've just got to eat some of the skin, order Original Recipe instead of Extra Crispy, which is 45 percent extra fatty. * You could eat three servings of Mashed Potatoes with Gravy (not that you'd want to) and still get fewer calories and less fat than you'd get by eating one order of French Fries.

Best Bites: Corn on the Cob, Mashed Potatoes, Original Recipe Chicken Breast without the skin, Cole Slaw. WENDY'S * Don't reward yourself for having a salad by eating a Chocolate Chip Cookie for dessert. It has more fat and about the same number of calories as a Single Hamburger. * At the salad bar, steer clear of the Cheddar Chips, Pasta Salad, Potato Salad, and Cole Slaw. Together, they'll give your salad 110 more calories and twice as much fat as a Single Hamburger. * If a Plain Baked potato doesn't seem filling enough (ask for margarine on the side, and use only one pat), have another. You'll still get no more calories and much less fat than if you ordered a Baked Potato with Cheese, Sour Cream, Chili & Cheese, Bacon & Cheese, or Broccoli & Cheese topping. * At the SuperBar, go for the tortillas, beans, rice, and pasta rather than the tacos, meat, and garlic toast. * You can eat two Jr. Hamburgers and still get fewer calories and less fat than you'd get in one Big Classic.

Best Bites: Chili, Jr. Hamburger, Fish Fillet, Salad Bar with Reduced-Calorie Italian Dressing, Plain Baked Potato, SuperBar. * Try the new French Dip Roast Beef Sandwich. It's got a third less fat than the Regular roast Beef. * Arby's can't seem to do chicken right. The Regular Roast Beef has less than half the fat and no more saturated fat than a Roast Chicken Club or Chicken Cordon Bleu. * The Grilled Chicken Barbecue is probably your best chicken choice. It has at least a third less fat than the Chicken Breast Sandwich, (but still a third more than the French Dip Roast Beef Sandwich).

You could eat two Turkey Deluxes and get 50 fewer calories and a third less fat than if you ate one Steak Deluxe. Order your Turkey Deluxe without the mayo and you'll save almost half the fat and 80 calories. * Make a meal out of a French Dip Roast Beef Sandwich, a plain Baked Potato, and a Side Salad with Light Italian Dressing. * For dessert, try a Blueberry Muffin instead of an Apple Turnover, and save two-thirds of the fat and a third of the calories. * Don't be seduced by the healthysounding Chicken Cashew Salad. It has almost as much fat (37 grams) as the Sausage Platter, and 40 percent of the saturated fat you eat in a day. * Get your Baked Potato plain. If you want some topping, go for the Mushroom & Swiss, which has half the fat and about 100 fewer calories than the Broccoli & Cheddar. Best Bites: French Dip Roast Beef Sandwich, Turkey Deluxe, Plain Baked Potato, Grilled Chicken Barbecue, Garden Salad with Light Italian Dressing, Blueberry Muffin. Jill Mathews helped compile information for this article.