At age 72, most people have either retired or are contemplating a life away from the rigors of work and the pressures of business.

Israel Cohen, chairman, president and chief executive officer of Giant Food Inc., is one of those rare exceptions. His father N. M. Cohen, a pioneer of the supermarket concept and a cofounder of Giant, remained active in the company until three years before his death last year, at age 93.

Today, amid widespread speculation about Giant's future as an independent regional supermarket chain, Israel Cohen seems more determined than ever to match his father's endurance. Indeed, Cohen served notice last week that he has no intention of relinquishing control of the nation's 10th-largest supermarket chain, especially now, on the threshold of the biggest expansion program in its 49-year history.

"I'm not going to go beyond 18 years from now because I'm only 72," Cohen said during an interview at the chain's headquarters in Landover. "My dad was active until he was 90. So, I'm going to predict for the next 18 years, hopefully, that I'm going to be managing this company. . . . Beyond that, I'm not going to make any predictions."

By the time Cohen reaches 90, Giant expects to have added at least 72 stores to the 132 it currently operates in the Washington and Baltimore areas. That projection is based on the company's goal of four new stores a year, a goal Cohen said is "attainable."

Already, Giant has completed plans to open 20 new supermarkets over the next 30 months. All but one will be local. Officials declined to identify the exception, explaining that Giant has not yet signed a lease for the property.

"It's going to be the greatest expansion in our history, so now certainly wouldn't be the time" to consider a merger or possible acquisitions, Cohen said, contradicting recent rumors that Giant might be a takeover target or might attempt to expand by buying other chains.

Those rumors gained momentum last month after Cohen confirmed that Giant had renewed talks with Pathmark Supermarkets about the possibility of manufacturing and processing food items for the New Jersey chain. Giant's extensive manufacturing operations include making or processing ice cream, bakery products and dairy foods for sale in its stores only. Shortly, it will begin making soft drinks and ice as well. Cohen said negotiations with Pathmark are still under way, but he denied they have anything to do with a merger. In fact, he said, neither a merger nor acquisitions are in the cards, at least for now.

"We've said that our diversification is vertical, in terms of our dairy, our bakery, our ice cream plant and our beverages that are coming on stream, and our ice manufacturing operation," Cohen said. "We have that expertise, and we're prepared to go anywhere with any company that has enough sales volume to justify any of these manufacturing facilities. We would invest half the equity, run the facility and take half the profits."

According to company figures, Giant processes more than 1 million gallons of dairy products a week, and more than 3 million gallons of ice cream and 7 million pounds of bakery products a year.

With that kind of production, Giant might be expected to launch a major food manufacturing program for several supermarket chains. But Cohen prefers to proceed slowly. "We're not going to try any more than one company at the outset. . . . We're going to test the water and see whether it's a viable thing and see whether it's profitable."

Analysts say that apparently cautious approach to a new venture is typical of a nonetheless innovative and aggressive style that has propelled Giant to its position as an industry leader.

One of the industry's biggest success stories began in the early 1930s, when N. M. Cohen was operating his family's three grocery stores in Lancaster, Pa. Cohen watched with interest the development of the first experimental supermarkets in the United States. About the same time, he met Jac Lehrman, whose family owned a food distributorship. Cohen proposed that he and Lehrman's father, Samuel, open a supermarket in Washington, a large, self-service store that would sell a high volume of merchandise at lower prices. That first Giant store, on Georgia Avenue in Northwest Washington, opened in 1936 -- 49 years ago this month.

With a hefty 41 percent share of the metropolitan Washington market, Giant has grown up to become the acknowledged leader among food chains doing business here. It is also technologically far more advanced than most other chains, giving it an edge in other aspects of the business as well.

Over objections from consumer activists and amid considerable skepticism within the industry, Giant installed its first computerized checkout scanners 10 years ago. By 1979, it had equipped all its stores with scanners, making it the world's first chain to do so. Some industry sources say the scanners saved Giant $15 million in the fiscal year that ended in February 1983.

Giant also has expanded its dry grocery warehouse and has built a combination ice cream plant and frozen food warehouse in Jessup. Both facilities have been described as the most sophisticated in the industry; receiving, retrieval and shipping operations are controlled by computers in elaborate, semi-automated systems.

Again, adapting technology to its retail operations, Giant started installing mini-computers in all of its in-store pharmacies two years ago. The computers not only store prescription records, but also alert pharmacists to potentially dangerous interactive effects of prescriptions.

Although company officials would not provide specifics, there is little question that Giant has used technology to slash costs, boost profits and pull away from competitors. Even now, Giant's data processing division is hard at work on at least a dozen new ideas that, for example, will help measure productivity, improve inventory control and even tailor cuts of meat and deli portions to customer buying patterns at different stores.

Giant's climb to success, however, hasn't always been smooth. For example, a combined food/department store called Super Giant and introduced in 1958 proved less successful than anticipated, and the nonfood items were phased out. Although Giant has continued to change the merchandise mix in its supermarkets, except for the pharmacies, it has stuck basically to food items.

The success of Giant's Pants Corral apparel stores notwithstanding, Cohen has ruled out any further attempts at mixing dresses and salad dressing.

"We've made all the mistakes we're going to make," he declared. "We're going to stick to what we know best . . . which is the food-drug combination. We've learned a lot, naturally, from our gourmet store in McLean and we use that as a laboratory. . . . Whatever makes sense and whatever stores can support will be part of the total mix."

Giant's supermarket/pharmacy combinations aren't likely to be written off as mistakes, but in a bold attempt to capture greater market share, Giant has grudgingly sacrificed some profits in a carefully planned price war with major drug chains in the region. Giant's stores comprise the fourth-largest drug chain in metropolitan Washington and are closing in on third place. Company earnings declined in the quarter following introduction of the new pricing strategy in 1984, and results at the end of that quarter showed the strategy caused earnings to decline.

The fourth quarter of fiscal 1985 ends this month, so officials do not yet know how the pricing strategy will affect year-end results.

"What we can tell you is that our customer count and our customer transactions are running well," said David B. Sykes, Giant's secretary and senior vice president for finance. "Our sales volume will end up just short of a 10 percent increase for the year, which means that we've held up very well."

Giant has held up so well under the competition that the pricing strategy has become a permanent program, Sykes said.

The lower prices have helped Giant achieve its primary goal of getting people into its drug departments. The pharmacy customers "spill over into the food division," he said, boosting Giant's overall business. "We look at the total earnings picture," Sykes said.

"Our people describe it as a synergistic effect," Cohen added.

Analysts describe Giant as one of the best managed companies in the United States. "What I think is outstanding about Giant is Izzy Cohen and his associates," said Eliot Benson, director of research at Washington's Ferris & Co. "They don't sit on their laurels. They are constantly trying to improve. That's one of the good features of Giant."

Benson estimates Giant's earnings will be about $3 a share for the current fiscal year and $3.30 a share for fiscal 1986. By comparison, the company earned $40.5 million, or $2.77 a share, last year on sales of $2 billion. The drug discount pricing strategy cut into Giant's margins, Benson said, but he believes the company "will achieve some benefit from that. I'm still looking at $3 a share, which is around $44 million in profits. I think that's good."

Cohen avoided any reference to dollar amounts, but said Giant's growth has been "somewhere between 7.5 percent and 10 percent" for as long as he can remember. In fiscal 1985, he predicted, "we will have increased our business -- without any new stores -- somewhere around 9.7 percent."

At least some of that business probably comes from improved market share, Cohen said. "It had to come from somebody," he said, without suggesting which competitors lost customers to Giant.

Cohen is confident of carving out a bigger share of the regional market, regardless of the competition and suggestions by some industry sources that the Baltimore-Washington corridor may already be saturated with supermarkets.

But while Giant continues to build stores, Cohen and his management team also are developing new angles to solidify customer loyalty, increase the chain's competitive edge and boost profits. The key, industry observers point out, is Giant's support systems. For example, GFS Realty, its real estate division, builds all of the chain's supermarkets and mini-malls. Giant recently expanded that division and plans to become more heavily involved in the construction of warehouses and other buildings in metropolitan Washington.

But Giant's real strengths lie in its food merchandising and its ability to respond quickly to consumer trends. Company-made soft drinks and ice are being added this year, but officials seem most excited about a new, nondairy soybean-curd ice cream Giant is developing. The product, called Dreamy Tofu, will be available within 90 days.

Despite its history of innovation and its high market share, Giant has proved less attractive to investors than to consumers. Benson said Giant's stock -- which closed Friday at 29 1/4, up 1/8 -- has been selling at a discount to the market in general and to other food chain stocks. "Yet it is a superior company to a lot of others. They have impressive sales and earnings figures, and they have Izzy Cohen."

Even before he was named chairman in 1978, Cohen developed an industrywide reputation as a shrewd but astute executive. "I may not be the best chairman, but I'm an excellent grocery man," Cohen often says.

And he effectively controls Giant, given the company's structure, in which the Cohen and Lerhman families own all voting shares. Cohen insists, nevertheless, that little would change if he were no longer in control.

"Let me put it this way," Cohen volunteered. "We have in the past 2 1/2 years lost five vice presidents, and we haven't missed a beat. We're very strong in management at every level. We have seven people on our management committee, and any one of them could step in and take my place." CAPTION: Pictures 1 through 3, Bedvier Davis in the bakery section at the Giant on Rockville Pike. Customer Carla Koller samples gourmet foods while employes Judy Payne, and Eileen Folkes watch. Joe Casamento and Larry Koonan display selctions from gourmet meat section at the Rockville store. Photos by James Parcell -- The Washington Post; Chart, A chronology of Giant Food's growth:

1936 -- N. M. Cohen and Samuel Lehrman open first Giant supermarket.

1941 -- Giant opens the first supermarket outside the District, in Arlington.

1946 -- First Giant opens in Maryland.

1948 -- Giant's Heidi Bakery begins production of the chain's private-label bakery products.

1958 -- The first Super Giant, a combination supermarket and department store, opens in District Heights.

1959 -- Giant completes first public stock offering.

1962 -- First Giant pharmacy opens, leading to the food/pharmacy concept in all of the chain's supermarkets.

1973 -- Computer-controlled dry-grocery warehouse opens in Jessup.

1974 -- Giant opens 100th store.

1975 -- First computerized electronic scanners are installed.

1978 -- Israel Cohen succeeds his father, N. M. Cohen, as chairman.

1982 -- Computer-controlled frozen food distribution center and ice cream plant become fully operational at Jessup.

1983 -- Sales top $2 billion for the first time. Giant opens Someplace Special, its first gourmet specialty store.

1984 -- Giant adds plastic-milk-bottle manufacturing plant to its headquarters in Landover. Opens first of new combined food-pharmacy-gourmet stores.