Larry Brown looks tired these days, or maybe discouraged. Six weeks ago, Brown, the chairman of the Physician Task Force on Hunger in America, published a national study. It was the latest in a series of reports documenting the return of hunger in America. By the doctors' reasonable estimate, 20 million Americans are chronically without enough food.

"The recent and swift return of hunger to America," said the task-force report, "can be traced in substantial measure to clear and conscious policies of the federal government."

The study made news, and Brown made the round of networks and editorial boards. There was the usual spate of editorials, most of them in favor of the physicians and opposed to hunger. And then, nothing. No surge of outrage from well-fed Americans. No emergency bills in Congress to fill stomachs. Most of the old congressional allies behaved as if they were spiritually malnourished. They were no longer able to raise the energy for battle.

Brown, an intense, sandy-haired public-health advocate, saw firsthand how the debate in Washington on social policy issues has been reframed. As he says, the policy-makers don't talk about how to get more for people in need anymore. The two-sided argument is now between people trying to hold the line on poverty programs and people trying to make deeper cuts.

The ground has shifted so profoundly that federal eyes glaze over when they scan a list such as the one presented by the doctors: Increase food stamps, improve meal programs for children, expand nutrition for pregnant women and infants and the elderly.

The big action on the American food front during the weeks since this report is a proposal by Sen. Jesse Helms to chop food stamps by another $3 billion to $5 billion. It isn't what you might call a serious bill, not one that will pass, but it says something about current policy negotiations. "The debate," says Brown unhappily, "is between maintenance and doing worse."

Brown knows that fully because he's made the trip from the Harvard School of Public Health to the Capitol enough times to qualify as a traveling salesmen with one pitch: People are hungry. They are not, he says quickly, starving as they were in the '60s, or starving as they are in Ethiopia. Now they are out of luck when the food stamps run out, when the regulations are changed, when the school breakfast program is canceled.

Usually, on this sales tour, he is one of many public-health people who want to write their patients a prescription for food but cannot get it filled. They take out the same shopworn samples: a 10- year-old boy the size of a 6-year-old; a refrigerator with only beans in it; a pregnant woman who hasn't had milk for five days; a family that eats only 23 days a month, until the food stamps run out. They choose to believe that sometime soon, enough of the people who make policy will buy.

"All I know from a health perspective is what's going to happen to those kids who aren't being fed," says Brown, "I'm convinced ultimately our public policies have to reflect the decency of the American people." But the words, vintage pre-Reagan ideals, echo in the halls of Congress. Today we put pictures of missing children on milk cartons, but we don't look as hard at those children who are also missing a chance to grow up strong.

The odd part of the lack of interest in hunger programs is that these are not programs that failed. The claims of program abuse don't stand up to scrutiny. If ever there was a success in federal aid, it was in food programs.

Maybe the problem is rather that the poor keep getting hungry. The poor are like that. Feed them on Monday and they'll want to eat again on Tuesday. The children are the worst, because they eat more per pound than adults. Maybe the rest of us expected to win a war on hunger -- serve one giant banquet -- and then quit.

But hunger is a byproduct. "The fundamental problem is not hunger, it's poverty, " says Brown. Every one of the hungry knows that, but until we chase away poverty, we have only two choices: we can feed or we can starve the poor.

That's why Larry Brown will be back to Congress this week with another letter. "We have to keep pricking their conscience," he says. This one will be signed by most of the heads of the public-health schools and a hefty assortment of religious and medical people in the country.

It will ask Congress . . . well, you know what it will ask Congress. Food for the hungry. The same old thing. But these are lean days for Larry Brown's people.