A public-interest group seeking more healthful school lunches drew a bead on whole milk yesterday, calling upon Congress to ban milk with more than 2 percent fat from school cafeterias.

The Citizens' Commission on School Nutrition also called for increased spending on the school lunch program, and urged schools to reduce the overall fat content of lunches to 35 percent of calories within the next two to four years. Ultimately, it said, the standard should be 30 percent.

"I think whole milk's days are numbered in the school lunch program," said Michael F. Jacobson, executive director of the Center for Science in the Public Interest. The school nutrition commission was organized by the center, a nonprofit organization that promotes improved health and environmental policies.

Susan Acker, a spokeswoman for the Agriculture Department, which administers the school lunch program, noted that milk for the lunches was required to be low-fat at one time. Congress passed legislation in 1979 requiring that whole milk be served, and the department since has issued rules requiring that the full range of milk, from skim to whole, be available.

The commission's report said a meal of grilled cheese and peas, served with whole milk, draws 41.4 percent of its calories from fat. This would be reduced to 37 percent with 1 percent milk and to 34 percent with skim milk, it said.

Another organization, Public Voice for Food & Health Policy, said the recommendations do not go far enough. Public Voice has called for Congress to require limiting the fat content of school lunches to 30 percent of calories.

The Agriculture Department has issued guidelines establishing this as a non-binding standard for Americans, but Acker said the department believes it is "going to be a slow process" to put it into effect.

Asked for comment on the commission's report, she said, "We are in agreement with a number of the recommendations they made, but they would like to see us move toward them more quickly than we think we will be able to."

An estimated 24 million children eat federally subsidized school lunches.

"With more single-parent households, more working mothers, and more children in poverty, school lunches are more important than ever," the commission said.

"For many children, the school lunch has made the difference between going hungry and being satisfied, between being undernourished and being well fed," it said.

The panel called upon Congress to "greatly increase" the amount spent per student on school lunches but did not say how much additional money was needed. It said current funding, adjusted for inflation, is 58 percent of what it was when the program was started in 1946.

One of its members, Vivian Pilant, director of school food services for South Carolina, said it would take at least $200 million to implement the department's non-binding guidelines in school lunchrooms.