At least 1.5 million people in 36 metropolitan areas around the nation are hungry because federal food programs and emergency efforts by private groups are failing to meet their food needs, according to a survey by the Bread for the World Educational Fund.

Bread for the World, which describes itself as a Christian citizens' movement, said that at nine large urban locations it surveyed last summer soup kitchens and other nongovernment emergency-feeding operations were serving an average of 16.25 percent more people than in 1984. The finding suggests that hunger problems are as bad or worse than a year ago, although probably not increasing as fast as during the recession.

In Boston, caseloads rose from 94,718 per month in 1984 to 123,389 in 1985, a 30 percent jump. The increases in Houston and Nashville were also 30 percent, the organization said.

The survey, part of the group's ongoing Hunger Watch U.S.A. project, was funded in part by a grant from the Ralston-Purina Trust Fund.

The report said cuts in food stamp and other federal programs over recent years have been putting "unbearable pressure" on private providers of food to the hungry. For example, Bread for the World said, food stamp outlays, estimated at about $12 billion for an average caseload of 20 million people a month in 1985, would have been $7 billion greater over fiscal years 1982-85 but for program reductions.

Voluntary agencies, as a result, are "staggering under the burden of caseloads totally inappropriate to their resources," the report said in calling for increased federal spending. Much of the current burden comes in trying to help those who exhaust their benefits before the end of each month.

The report said responses from 21 major sites of the 36 surveyed in 1984 or 1985 showed that 59 percent of people eligible for food stamps were receiving them, leaving 807,000 eligibles without the stamps. It said some people "dread the social stigma" of applying, some do not realize they are eligible and others are kept off by administrative error or delays.

The report said that nationwide the Women-Infant-Children program (WIC) of nutritional supplements for children under 5 and pregnant women provides $1.5 billion and serves about 3.1 million people, a third of those eligible. The report also estimated that about 225,000 poor children eligible for free school meals were not receiving them at sites that responded to the survey.

The extent of hunger in the United States has been a major public dispute for several years. Citizens' groups, the U.S. Conference of Mayors and other local and state government agencies have argued that hunger is growing and have opposed Reagan administration efforts to cut or cap federal programs. A Physician Task Force on Hunger headed by Larry Brown of the Harvard School of Public Health estimated Feb. 27 that at least 20 million Americans go hungry at least two days a month.

A presidential task force earlier had reported, without giving any numbers, that hunger existed in the United States but was not "rampant."