Sanford A. Miller, the candid and articulate director of the Food and Drug Administration's Center for Food Safety and Applied Nutrition, resigned Monday to become dean of the graduate school of biomedical sciences at the University of Texas Medical Science Center in San Antonio.

As head of the FDA's Center, Miller, 56, was responsible for overseeing the safety of the nation's food supply, a mandate that ranges from regulation of food additives to nutritional labeling. Holding the position since 1978, he served under four FDA commissioners and two administrations.

Miller, who "came for two years but stayed for nine," said his decision to finally leave the agency was based on the facts that he is "burned out," that the job in Texas was offered to him, that the agency is in a "big flux in terms of regulatory philosophy" and that it would be better if "someone else carried the debate."

He would not elaborate on this debate, nor would he discuss particular issues over which he and the agency's commissioners have been at odds. As for differences of opinion, he said that over the years "in some cases, I was right, in some cases, they were right."

A self-described "liberal New Englander," who was personally well liked by people in industry as well as by consumer advocates, Miller was a unique player in the midst of the Reagan administration. Some observers, however, believe that his power had been usurped and that he had stopped fighting in recent years.

"His wings were clipped by being in an agency devoid of power. He hasn't been able to do many of the things he wanted to do," said Michael Jacobson, executive director of the Center for Science in the Public Interest. Jacobson said he is concerned that Miller's successor, yet to be announced by the agency, will be a "Reagan appointee who knows little about nutrition and cares little about health."

Miller said that one of the frustrations during his tenure was the agency's de-emphasis on attacking fraud in the food industry. He said he would have liked to have done more with nutritional information programs -- specifically the agency's unrealized plans to revamp nutrition labels on food packages.

At the same time, he said that the danger of microbial hazards in the food supply is one of the most potent issues facing the agency today and one to which the agency needed to direct its resources.

Entering government with the view that most of the delays and faulty decisions were based on ineptness, Miller said he now believes that the "people aren't incompetent; it's just that they are bound by an extraordinary set of rules that compel delay."

Miller said that beginning in 1979, the agency redirected itself, emphasizing regulations based on good science, not just "blind application of the law" and that the tools to guard safety should be flexible, rather than based on stringent enforcement. Strict enforcement would require an agency with "100-fold" the amount of existing resources, he said.

"There is no way for the government to ensure that your food is absolutely safe," he said, adding that the public itself has a role to play, both in employing safe food preparation and in letting its positions be known through Congress and through its pocketbooks. He said that the "reason why consumers are less powerful is because they think they're less powerful."

Two of the toughest decisions he had to make, said Miller, were those regarding the approval of aspartame and certain uses of food irradiation. He said that he wasn't unsure of these decisions, but that he did not anticipate the level of consumer response and opposition to aspartame.

Miller, a connoisseur who studied the dynamics of food, culture and cooking as much as he did the interactions of food, politics and science, belonged to a gastronomic society of FDA staffers and used to raise his own trout and salmon in tanks while living in Boston. (He did, however, say that he rarely ate lunch at work, instead subsisted on countless cups of coffee.)

He said he would not dismiss working for the government again and did not see his resignation as signaling the end of an era at the FDA's Center. "I got on the roller coaster at one point. Now I'm getting off," he said.