BEFORE National Nutrition Month slips through our fingers we should take another close look at the U.S. Dietary Guidelines. The apparently innocuous guidelines have been at the center of controversy since their release in 1980 by the U.S. Department of Agriculture.

First, some industry groups assert that the advice conveys to consumers a negative connotation about certain foods. Burt Eller, vice president of the National Cattlemen's Association, says, "While the guidelines didn't say don't eat meat, they were just paraphrased that way; it became transposed as a don't-eat-meat document."

Now the USDA is appointing a number of scientists to determine the validity of the advice and to recommend appropriate changes (if any). While no one has been named officially to the panel, some consumer advocates criticize probable choices as being too closely associated with the food industry, another point of contention.

And such nutrition experts as Dr. Jean Mayer, nutritionist and president of Tufts University, have criticized this administration for "abandoning" the guidelines--a third point of contention. After distributing more than 7.5 million copies, the USDA has quit printing them. Assistant Secretary of Agriculture Mary Jarratt says this is a perfect opportunity for private sector initiative. The guidelines are in the public domain with no copyright restrictions. Consequently, anyone who wants to reprint them can do so without special permission.

All the brouhaha that surrounds the guidelines may perplex those who learned nutrition from their third grade teachers. The rules sound the same.

* Eat a variety of foods

* Maintain ideal weight

* Avoid too much fat, saturated fat and cholesterol

* Eat foods with adequate starch and fiber

* Avoid too much sugar

* Avoid too much sodium

* If you drink alcohol, do so in moderation

A dinner consistent with the guidelines is easy to throw together after a quick trip through the express lane of the supermarket, provided you have flour, sugar, salt, pepper and butter or oil on the shelf at home. EXPRESS LANE LIST: grouper or other fresh fillets, white wine or clam juice, zucchini, mushrooms, parsley, bread or bread crumbs, cheese, cabbage. BAKED GROUPER (4 to 6 servings) 2 pounds fresh grouper fillets or other fish 1 cup white wine or bottled clam juice 1/2 teaspoon freshly ground black pepper Salt to taste 1/4 cup chopped parsley

Place fish in lightly greased ovenproof dish. Add wine, salt, pepper and parsley. Bake at 350 degrees until fish is no longer translucent, about 10 or 15 minutes. Remove fish to heated platter and boil the liquid until it's reduced to 1/4 cup. Pour over fish and serve, garnished with extra parsley, if desired. STUFFED ZUCCHINI (4 servings) 4 medium zucchini, about 6 inches long 8 ounces fresh mushrooms 4 tablespoons vegetable oil 1/2 cup chopped parsley 2 slices whole-wheat bread, made into crumbs

Salt and pepper to taste

4 to 6 tablespoons grated cheddar or parmesan cheese

Trim the ends off the zucchini and hollow them out, leaving 1/4-inch shell. Drop the halves into boiling water for 1 minute. Chop the zucchini you have scooped out and set aside. Chop the mushrooms. Heat the oil in large skillet and add the mushrooms, chopped zucchini and the parsley. Cook over medium heat until the mushrooms have given up their liquid and turned dark. Add the bread crumbs, salt and pepper to taste and stir to heat through. Fill the zucchini shells with mushroom mixture and sprinkle with cheese. Bake at 350 degrees for 15 minutes. Serve with baked fish and chopped cabbage saute'ed in a little butter until wilted.