Secretary of Agriculture Bob Bergland just loved the "school lunch" he and about 100 government officials and reporters sampled recently.

Big juicy cheeseburgers, still sizzling as they were placed in buns; tender, moist chicken right from the oven: freshly baked whole wheat muffins.

It all the nation's schoolchildren could eat like that every day there would be not plate waste because the kids would like their lunchs as much as Bergland like his. He told reporters: "It's as good as my wife can do and she's the world's best cook."

As part of USDA's efforts to improve the quality of the meals served in the school lunch and breakfast programs the agency has been attempting to revise some of the regulations governing those meals. But it has been running into a lot of roadblocks. USDA's attempts to get rid of "junk" food in school vending machines and the high-sugar, high-fat cupcakes being served in some school breakfast programs have met with strong lobbying pressures by those who want to sell such products to schools. In addition the department supplies the schools with only 20 percent of what is served. And USDA has very little control over what happens to that food after it arrives in the school cafeterias.

Of course the meal Bergland sampled was not the garden-variety school lunch, a fact he acknowledged when he said: "This is the fanciest school lunch in captivity." And the secretary should know. He's tasted a number of them since he took office. One he had to force himself to swallow, and has been unable to forget since, featured a burnt toasted cheese sandwich at a Montgomery County school which had no facilities for on-site preparation.

"If the food is not given tender loving care," Bergland said, "it's a mixed bag."

Lack of kitchen facilities, school cafeteria workers who can't cook or don't care, school personnel who are only interested in turning a profit instead of turning out a decent meal are responsible for the uneven quality of the $2.5 billion school lunch program nationwide.

The hamburgers are more likely to sit on a steam table for an hour before they are served, which makes them taste steamed instead of grilled. Steam tables have the same effect on the chicken. Canned vegetables take on a grayish cast when they "stew" in their own juices.

Often the food isn't even prepared at the school, but hundreds of miles away, after which it is cooled down, wrapped, frozen and shipped. The quality and taste are significantly decreased by the time the reheated TV-type meals reach the students.

But USDA appears to be making the effort to improve its quality of what they supply, particularly to cut down on the fat, sugar and salt content. To illustrate the difference between the products previously purchased and those the agency has purchased or is considering purchasing, samples of the "old" and "new" varieties were available at the tasting.

Hamburgers were made with beef that contained 22 percent fat and 24 percent fat. Some of the fruits were canned in both light syrup and unsweetened fruit juice instead of the heavy syrups used in previous years. There were samples of canned corn packed with and without sugar and salt. The new frozen potato rounds are free of artificial color and monosodium glutamate.

These are the federal government's contribution to elimination of plate waste. But as Assistant Agriculture Secretary Carol Foreman noted: "We can only do so much. The school lunch program must have the involvement of local children and parents and the local PTAs."

That is only part of the problem, however. Even when parents and local school lunch administrators indicate they want certain changes made in federal regulations, their desires are often thwarted by efforts of the food industry.

An attempt by USDA to remove the fortified cookies, cakes and donuts, the so-called "grain-fruit" products, like Super Donuts and Huzzahs, from the school breakfast program has met with intense congressional lobbying efforts by the manufacturers of these products. Congress has not yet decided whether a decision about the use of such products in the school breakfast program should be placed in the hands of the secretary or turned over to the local schools.

Bergland feels "very strongly" that the grain-fruit products which are high in sugar and fat and devoid of many trace nutrients found in natural food should be banned. "My major concern," he said, "is that we are teaching kids poor eating habits."

USDA is also meeting stiff resistance in what some call a "half-baked" attempt to get "junk food" out of the school vending machines. A vast majority of the 2,100 public comments on the junk-food amendment to the school lunch regulations supported a ban but wanted it broadened. USDA proposed banning only the sale of carbonated soft drinks, frozen desserts, candy and chewing gum. Many of the comments from the snack food and vending industry interest implied that if the ban were to go into effect, they would take legal action.

There was strong opposition from Hershey Foods, whose legal counsel is Peter Hutt, former general counsel of the Food and Drug Administration. Hershey claimed that the proposal "arbitrarily discriminates among nutritionally comparable foods."

The National Soft Drink Association said there was "not one shred of evidence" that soft drinks contribute to decreased participation in school lunches.

The spokesperson for the Retail Confectioners International said candy is not junk food, that its ingredients are nutritious.

Proponents of the limited ban were extremely angry. Said one: "Here again you have industry coming up with a good lawyer."

Foreman said if the department attempted to implement the ban at this time, "I suspect we would end up in court."