People are becoming increasingly aware of the need for non-nutritive fiber in the diet. One of the most obvious places to get fiber is from whole grains in both cereals and baked goods.

However, it's just as easy to come up with high fiber main dishes that the whole family will enjoy. What's more, the larger your repertory of these recipes, the more variety you can provide in weekly menus.

Just what is dietary fiber? According to the USDA's new handbook on food, it is "plant material which is not digested in the gastrointestinal tract of man . . . Plant foods - whole-grain breads and cereals, bran, dry peas and dry beans, nuts, fruits and vegetables -- particularly those that are unpeeled or have edible seeds -- are considered good sources." (To obtain the booklet write: Usda, s.e.a., Washington, D.C. 20250 and request "Foods," Home & Garden 228.)

While there is actualy no nutritional value to fiber, research has lead many experts to believe that increased fiber in the diet will help protect against colon cancer and other chronic degestive problems.The USDA also notes that "fiber is a plus in weight reduction because bulky foods fill you up."

Following is an interesting collection of delicious and filling high fiber main dishes. BEEF AND VEGETABLES OVER BULGUR (4 to 5 servings) 2 tablespoons cornstarch 1/2 teaspoon salt 1/8 teaspoon garlic powder 2 tablespoons brown sugar 2 tablespoons soy sauce 2 tablespoons white vinegar 1 pound round steak cut into 1/4-inch thick strips 1 medium onion chopped 2 tablespoons vegetable oil 2 ribs celery, sliced 1 cup water 3 medium-size green peppers, cut into 1/2-inch strips 1 large tomato, cut into wedges 1 cup bulgur or cracked wheat 2 cups water 1/2 teaspoon salt

Mix first six ingredients to make a marinade. Pour over meat and let stand at room temperature for one hour. Remove meat with a slotted spoon, reserving marinade.

Saute meat and onion in oil in a large heavy skillet over medium heat. Add celery and 1 cup water. Cover and simmer, stirring occasionally, about 30 minutes or until beef is tender. Add reserved marinade and green peppers, and cook an additional 10 minutes (or shorter, if you like peppers very crisp). Add tomato and heat 2 more minutes.

About 20 minutes before meat mixture will be done, combine bulgur, 2 cups water and 1/2 teaspoon salt in a medium saucepan. Bring to a boil, cover and reduce heat. Simmer 15 minutes, stirring ocasionally. Remove cooked bulgur mixture to a serving dish and keep warm. To serve, spoon meat mixture over bulgur. STUFFED EGGPLANT (4 servings) 2 eggplants (about 1 pound), or several very small ones 1/2 pound ground beef 1 clove garlic, minced 1 medium onion, chopped 1 medium green pepper, chopped 1 can (16 ounces) tomatoes, including liquid 1/2 teaspoon each dried thyme, basil and oregano Several grinds pepper 1/2 teaspoon salt or to taste 1/4 cup pine nuts 1/4 cup unprocessed bran 1/4 cup grated parmesan cheese

Slice eggplants in half lengthwise. Scoop out pulp leaving a 1/2-inch thick shell. (A grapefruit knife or spoon is helpful for this task. Chop up pulp and set aside. Place shells in a baking dish and set aside.

Brown beef in a large skillet, with garlic and onion. (If necessary, you can add a small amount of oil to aid in browning meat). Break up meat as it cooks, and drain off any excess fat. Add green peppers, tomatoes, herbs, seasonings, pine nuts and chopped eggplant. Break up tomatoes with mixing spoon. Cover skillet and simmer about 5 minutes, stirring occasionally. Remove from heat and stir in bran. Use mixture to fill reserved eggplant shells.

Sprinkle tops with parmesan cheese. Bake at 350 degrees for 30 to 40 minutes, or until eggplant shell is cooked through. Serve each person one or more filled eggplant shells. FALAFEL IN PITA BREAD (4 or 5 servings) 2 cups cooked (or one 16-ounce can) garbanzos (chickpeas), drained* 1 slice whole wheat bread 1/4 cup water 1 tablespoon flour 2 eggs, lightly beaten 2 tablespoons chopped fresh parsley 1 tablespoon sesame butter or tahini 1/2 teaspoon salt 1/2 teaspoon turmeric 1/4 teaspoon each pepper, cumin, garlic powder, basil and marjoram 1/8 teaspoon cayenne pepper Whole wheat pita bread plus lettuce, tomato, tahani or yogurt as garnish

*If using dry garbanzos, prepare in advance according to package directions.

Set aside to cool before using.

Place slice of whole wheat bread in food processor or blender to grind into crumbs. Remove to a bowl. Place cooked (or canned) garbanzos in food processor or blender with water, and process until coarsely pureed. Add rest of ingredients and mix well.

Form into small patties or small balls (a small ice cream disher works very well), and shallow fry in a small amount of oil, or deep fry until falfel is lightly browned on both sides. Drain on paper towels.

Serv 2 or 3 in a whole wheat pita bread pockets with lettuce and tomato. Offer tahini and plain yogurt on the side to be used as a dressing, if desired. GARDEN MEAT LOAF (4 or 5 servings) 1 pound ground beef 1 cup shredded carrot 2 eggs, lightly beaten 1/2 cup shredded celery 1 small onion, finely chopped 1/4 teaspoon garlic powder 1/2 cup catsup 1 1/2 cups rolled oats 1/2 teaspoon salt 1/2 teaspoon mustard powder 1 tablespoon Worcestershire sauce

Combine all ingredients and mix thoroughly. Press into an 8 1/2-by-4-by-1/2-inch loaf pan. Bake at 375 degrees for 50 minutes. Cool 10 minutes before slicing. CHICKEN WITH FRESH BEAN SPROUTS (4 servings) 2 whole chicken breasts, boned 4 cups fresh bean sprouts 1 scallion, thinly sliced on the diagonal 4 tablespoons peanut or other vegetable oil 2 teaspoons cornstarch 1 egg white, lightly beaten 1 teaspoon salt or to taste 2 tablespoons dry sherry 2 to 3 cups cooked brown rice

Remove skin and any excess fat from chicken breasts. Cut into very thin slices, 1 1/2 to 2 inches long. (It may help to slightly freeze chicken first.) Place in a bowl with scallion and 1 teaspoon oil. Mix well. Add cornstarch and toss so that all chicken is coated. Add egg white, 1/2 teaspoon salt and dry sherry. Mix well. Set aside.

Heat 1 tablespoon oil in a wok or large skillet. Add bean sprouts and remaining 1/2 teaspoon oil. Stir-fry bean sprouts for about 2 minutes until heated through. They should remain crunchy. Remove with slotted spoon to a bowl. Drain liquid from wok and dry with paper towels.

Add remaining oil to wok and heat. When very hot, add chicken slices (including marinade) and stir-fry until chicken turns white and is done, about 2 to 3 minutes. Return bean sprouts to wok with chicken and stir-fry until completely mixed. Serve immediately over cooked brown rice.