By this time next year, the scene should be changed, but now, boxes of doughnuts, cream-filled coffee cakes, chocolate buttercream cupcakes, soft drinks and other sugary confections line the shelves in the kitchen at Greenbelt Junior High School.

Out in the center of the kitchen, in counterpoint, cafeteria workers are hard at work on more nutritious items, seasoning cut-up chicken, mincing ham for ham salad sandwiches and trying to transform vegetables into something Prince George's County students will eat.

For the time being, students in Prince George's County secondary schools have a choice - junk food or meals carefully designed to meet their nutritional needs. This year they can buy the federally approved school lunch, or they can buy corn chips, potato chips and sweet, gooey pastries and wash it down with a carbonated soft drink. In September, in line with a school board resolution, that will be changed.

It is a change that was taking place already, more slowly, according to the director of food services for the Prince George's County schools C. Anthony DiMuzio. Each year, he said, he had been limiting year by year the types of "junk" food available and substituting more substantive items.

In March, the school board adopted a resolution, speeding up the process, calling for the phase-out to be complete by Jan. 1, 1978 - the middle of next school year.

"Basically we're saying we approve of the direction the director of food services is taking and want to speed it up," said board member Maureen K. Steinecke, who authored the resolution. Steinecke said that the board had been aware of DiMuzio's efforts but wanted to supplement them.

"It's hypocritical to teach one thing in the classroom and then be releasing students for lunch and doing the opposite," said Steinecke.

Cutting non-nutritious items out of the school lunch program sounds like a relatively simple task, something on which everyone should agree. But even in something as straightforward as eliminating junk food, there are questions and trade-offs that illustrate some of the larger questions and trade-offs in the school lunch program generally.

DiMuzio raises two possible disadvantages to the speeded-up removal of the junk foods - that students who were drawn to the cafeteria by the snacks now may go elsewhere, losing to him the chance to gradually wean them to more nutritious food, and that the school system may lose significant income from the sale of junk food that could add to the cost of the regular lunch.

"I'm afraid the kids will want to leave campus, and I'll lose them entirely," said DiMuzio. His approach, he said, had been more gradual, to educate them to eat better foods without scaring them off entirely by eliminating not-so-nutritious favorites and without losing revenue that junk food sales bring into the school lunch program.

DiMuzio, a former Marine who was commanding officer of the only formal food services school in the Marines, came to the school system three years ago. Since that time, he said, he has been trying to use the lunchroom for nutrition education, but doing it slowly and subtly "so the kids don't resist."

"Every year in the last three years, I've gradually been cutting down and limiting the non-nutritious items. I had given myself five years to cut them out," he said.

His phase-out had included cutting down from nine types of frozen desserts, including relatively non-nutritious popsicles and fudgesicles, to only four items - "all nutritive ice cream," he said. He had also begun limiting the numbers of types of chips and pastries, he said.

With the more rapid phase-out, "the question is what you replace them with" and whether you lose money in the transition, said DiMuzio, who said he is experimenting with yogurt salads, cheese and crackers, more fresh fruits, canned and frozen juices, school system made cookies and cakes and jerky.

DiMuzio estimates that so-called junk foods will generate about $226,000 in sales, or about 10 per cent of total revenues from school lunch and a la carte sales this year. If the profit from those sales had to be made up by adding to the cost of school lunch, it would amount to about a 3 cent increase for each lunch, said DiMuzio. Lunches now cost 50 cents in elementary school and 55 cents in secondary school.

Funding for the Prince George's County school lunch program now comes from three sources - sales, state and federal. The county makes no contribution.

"As a nutritionist, I'm committed to nutrition education," he said. "As a realist, I'm also aware of the likes and dislikes of young adults. As a businessman, I'm responsible for seeing that the program is self-supporting."

"It's hard to be all three, and sometimes it may appear as if I'm speaking with a forked tongue or only paying lip service to nutrition," DiMuzio said.

There have been occasional questions from parents about additives and preservatives, said DiMuzio, but there has been little pressure to remove all such ingredients, he said.

DiMuzio said he relies on the federal government for most of his expertise on additives and preservatives. When serious questions are raised about something, he tries to remove it, he said.

"We've had some inquiries about whether the school system should provide an additive-free meal," said Steinecke. "My response is, frankly it would be economically prohibitive. Just as for the allergic child, a parent has to really pack the lunch himself" so should a parent concerned about additives and preservatives, she said.

Some of what any school food director does is marketing. For instance, at one point in Prince George's County milk was sold in blue cartons, which lent a bluish cast to the milk in the sunlight, said DiMuzio. There were complaints that the low fat milk was thin and tasted different. When the milk was sold in red cartons, the complaints ceased.

Sometimes marketing is aimed at getting U.S. Agriculture Department donated commodities into the kids, incorporating cranberry sauce into punches made with fruit juices. Sometimes it is aimed at getting lunch into students who don't respond to the traditional hot lunch.

For instance, the Prince George's County school snow serve about 4,000 "pack-sacks" - a Type A lunch in a brown bag - out of almost 67,000 lunches served daily. (A Type A lunch meets federal standards, which require so much protein, and so much vegetables, fruit and cereal.)

"If a student doesn't want the lunch, he can grab a bag," said DiMuzio. "The kids love it. The older kids sit under trees and eat it, and the parent cannot pack or duplicate a type A lunch for 50 or 55 cents . . . We could even roll a car down the hall to a smoking area," said DiMuzio. "If a child won't come to me, I'll go to him."

Other variations on the standard school lunch program are less a function of marketing than of economic necessity. For instance, the school system serves 61 small elementary schools through satellite food preparation operations. Food is prepared elsewhere and taken to the school where it is served.

In Montgomery County, food is preplated and, according to critics, looks like TV dinners. With a few exceptions, food for Prince George's County satellite schools is prepared and transported in bulk and served in a traditional cafeteria line.

School lunch participation is up 11 per cent in the last three years in spite of shrinking school enrollment, DiMuzio said. "My food waste is pretty dadgum small," he said.

As in any system, there is apparent waste, however. Some food goes into the garbage."You can go to any school, and you'll see some meals less acceptable than others," said DiMuzio. "Maybe it's hot and they don't want soup. Maybe it's an activity day, and they're saving their money for an activity. Or maybe they don't like the preparation - there's same of that too," he said.

"On the balance, Prince George's County has done a better job than many other school systems," said Steinecke, a point of view also voiced by other board members.

"It's like a meal program in a home, quality is very dependent on the skill of the workers in the school," said Steinecke. "Just as some mothers are better cooks, some workers are better cooks."

"Most parents feel the food program is great," said Mildred Pati, a parent who is chairing the Prince George's County Council of PTAs task force on nutrition. "We feel education is needed more in the home than trying to do something in the school program. Many of the children don't like to eat some of the meals provided because they have never had the opportunity to try it in the home," she said.

"Home life now isn't like it was 25 years ago, with the family dinner. Too many parents are working and too many children are geared up on hamburgers, hot dogs and pizza . . . So many of us want to blame the lunch program or the school system when so much of this (nutrition education) must be done at home first."

In the long run, there is only so much a school program can do to insure that students eat well, said DeMuzio. "You're only feeding the kid five meals out of 21. You can't compete with the media bumbardment. You can't change children's eating habits. Parents have to do that at home," he said.