As John and Sue Block rounded the corner into "Aisle 1B: Meats" at their local Safeway yesterday, nine photographers opened fire from where they crouched behind the sliding windows to the butcher shop.

An NBC cameraman teetered close behind on a shopping cart propelled by his sound man. Another dozen reporters and seven more camera crews boxed out shoppers and gawkers in other aisles, the better to watch the secretary of agriculture and his wife buy a week's rations on a food stamp budget of $58 for a family of four.

Block, in shirtsleeves and pushing a cart, said he and his family--Sue, daughter Christy, 19, and house guest Joyce Hamilton, also 19--will spend one week eating strictly according to the department's Thrifty Food Plan, the program recommended for people on food stamps with zero income.

"I'm here to demonstrate that you can live within the plan and have a satisfactory diet," Block told the assembled media, as the entourage blocked traffic and toppled groceries from shelves for 40 minutes.

"In my farming work, I've always been willing to do any work I asked any of my men to do. I don't expect people to do anything I wouldn't do," said the millionaire hog farmer, who earns $69,630 as a Cabinet officer.

The food stamp program will help feed 22 million low-income Americans this year at a cost of $12 billion.

As Block and his wife collected four loaves of bread, ground chuck, generic processed cheese, hominy grits, corn flakes, dried milk and other thrifty staples, Congress had yet to pass a supplemental appropriation to keep food stamps flowing until Sept. 30. Both houses were expected to schedule votes today.

If all goes according to plan, Block's lunch today will be a brown-bagged sandwich of bologna (1 1/2 ounces) and cheese ( 3/4 ounce), with half an apple for dessert. He pledged yesterday not to cheat on his diet at the embassy parties and other black-tie affairs he routinely attends.

Staff reconnaisance, supplemented by Sue Block's native knowledge of the Little Falls Mall Safeway in Glen Echo allowed the Blocks to wheel purposefully through the store, shopping list in hand, without any pause for wrangling over the itinerary.

"Aisle 8 will be the canned tomatoes," aide Jerry Weller said, pointing the way for errant cameramen.

Loaves of Mrs. Wright's buttermilk bread, loose onions and a container of cottage cheese hit the floor in the procession's wake, the victims of narrow aisles and swinging equipment.

"It doesn't look too bad," manager Pat Morse said with relief as the circus prepared to clear out of the store. "Now I've got to clean up."

The Blocks then loaded their groceries into the family station wagon and drove to their $300,000 house.

Several shoppers said they wouldn't want to have to live on $58 a week.

"People on this end of town spend that much a week on their Perrier water," said Don Greenslade, who works across the street.

Some nutritionists and welfare rights lobbyists ridiculed Block's experiment in thrifty eating yesterday.

"It is so offensive," said Nancy Amidei of the Food Research & Action Center. "We've got food kitchens overflowing with hungry people, food pantries turning people away because they don't have enough food. We've got hungry people in evidence in every corner of the nation. And what is John Block doing? A publicity gimmick."

Nutritionist Lynn Parker said Block "is not dealing with the real world of poor families."

"A lot of families don't have the facilities that John Block's family has," Parker said. "They may not have a storage facility that's free of cockroaches and mice. They may not have a working oven and stove. They may not have the 90 minutes a day of preparation time to make these meals.

"It would be extremely hard for Mr. Block to put himself in that position. He doesn't have to choose between food and rent, or electric bills," she said.

Block, asked as he arrived at the Safeway whether he thought his trip was a publicity stunt, replied: "No, I certainly do not. I think it has got a genuine purpose, too."