A medical research team told a Senate subcommittee yesterday that the United States has far fewer cases of severe malnutrition than it had 10 years ago.

Nearly all of the progress in eliminating the instances of extreme hunger is attributable to federal food programs, the doctors said in a report, "Hunger in America: The federal Response," presented yesterday to the Senate subcommittee on nutrition.

"Our first and overwhelming impression is that there are far fewer grossly malnourished people in this country today than there were 10 years ago," the doctors said in the report.

"In the Mississippi delta, in the coal fields of Appalachia and in coastal South Carolina - where visitors 10 years ago could quickly see large numbers of stunted, apathetic children with swollen stomachs and the dull eyes and poorly healing wounds characteristic of malnutrition - such children are not to be seen in such numbers today," the doctors said.

The physicians, members of the Field Foundation Medical Team, which did a similar hunger study in 1967, said the decrease in malnutrition did not come about because of an overall improvement in the economy of the areas originally studied.

"In fact, the facts of life for Americans living in poverty remain as dark or darker than they were 10 years ago" the doctors said in the report, written by Nick Kotz and published by the Field Foundation.

"But in the area of food, there is a difference," the report said. "The food stamp program, the nutritional component of Head Start, school lunch and breakfast programs, and to a lesser extent the women-infant-children (WIC) feeding programs, have made the difference, the doctors concluded.

However, the largest of those programs-the $6.9 billion food stamp program, which helps feed 17.4 million Americans-is endangered by spending ceilings established in the 1977 rewrite of the food stamp law, the doctors told the subcommittee.

For example, rising food costs already are threatening to push food stamp spending beyond the current $6.9 billion limit. The congressional Budget Office estimates that food stamps will cost the government $7.5 billion in 1980, although the statutory "cap" for the program that year currently is fixed at $6.2 billion. The upshot could be a loss of at least $1.3 billion in benefits to food stamp particpants, according to the program's supporters.

"It is inconceivable to me that we would allow a reduction of these benefits," said Dr. Ray Wheeler of the Charlotte (N.C.) Medical Center, a member of the Field Foundation team.

"There is no necessity for apology or defense of the food stamp program . . . It is the most valuable health dollar spent by the federal government," Wheeler told the subcommittee.

The doctors, pointing to the new Field Foundation study, which was conducted between May and September 1977, said their evidence shows that more federal dollars are needed to support the food stamp program.

Dr. Gordon Harper of the Harvard Medical School said that "despite a great deal of individual effort to be thirfty, food stamp families frequently run out of food by the second week in the month, when they are usually down to flour."

Harper and his colleagues urged the senators to eliminate food stamp spending ceilings. "There is no room for economizing or cutting back in this program," Harper maintained.