DR. EDWARD Brandt had his work cut out for him. On the one hand, the assistant secretary for health in the Department of Health and Human Services had to rationalize cutting funds for a major, cost-effective public "preventive" health program. But in the same speech, he also had to support his contention that prevention "has become the most important issue of public health."

How does one support prevention in the same breath he mentions a cut in funds for an operation like the Women, Infants and Children program? The question constantly came up during a recent meeting of 120 members of the American Dietetics Association. They were in Washington to discuss current nutrition policy, and WIC topped their list of priorities.

The administration proposes to combine WIC (now run by the Department of Agriculture) with the Maternal and Child Health program (under HHS) in one block grant, in an effort "to bring some order into health care delivery," said Brandt. Before this proposal, "there was overlap and there was confusion." This particular proposal would mean a 25 percent cut in funds, which can be spent as the state sees fit within a very flexible set of boundaries (all of the money could go, ostensibly, to child health, with none guaranteed for the WIC program). The dieticians said the proposal contradicts any attempt at "prevention initiatives."

While people may complain vociferously about fraud and waste in many human services programs, nary a peep is heard about WIC. Indeed, when ADA members informally canvassed their congressmen, they reported the consensus was against any cuts in WIC.

The program provides vouchers for foods such as milk, infant formula, iron-fortified cereals and vitamin-C-fortified fruit drinks to pregnant women and infants. It has effectively reduced nationwide the numbers of underweight babies born to "at-risk" mothers -- women who are typically indigent and often have medical or nutritional problems that complicate pregnancy.

Several studies have shown that the WIC program saves health care money over the long haul. The well-nourished infant born to the well-nourished mother doesn't require intensive -- and expensive -- hospital health care. For every $1 spent on food to balance the diet of mother and infant, an estimated $3 is saved in health care costs.

The Department of Agriculture "has done a fantastic job of administering [the WIC] program through the states," said Barbara Ann Hughes, public health nutritionist in North Carolina, which has the fifth largest WIC program in the country. "They're moving [Food and Nutrition Service] employes and replacing child nutrition experts with party [Reagan] people." She added that her department isn't, in theory, opposed to the block grant proposal, "if we can have the same amount of money. That's the clinker."

ADA members took issue with the fairly obvious contradiction in Brandt's message. While he supported the administration proposal to combine programs and cut funds, he said the "chief cause of infant death is low birth weight," adding that the underweight baby is 20 times more likely to die in the first year than the baby of normal weight. He added that infant morality is "a complex problem with a complex etiology," citing the youth, drinking and smoking habits of the mother as factors that influence a baby's birth weight.

Prenatal care is another influence, said Brandt; mothers who have no nutritional counseling are three times more likely to give birth to underweight infants. The WIC program includes nutrition counseling.

Terry Williams, director of the 19-month-old WIC program in Wyoming, told Brandt, "We have a low birth weight rate twice as high as the state average in mothers not in the WIC program," and he called the proposed budget cuts a "very poor investment in preventive health."

The American Dietetics Association has released a position paper condemning the proposed WIC-MCH combination and budget cuts. @the paper cites a study which shows a "significant decrease" among WIC participants "in the incidence of low birth weight infants who are subject to costly preventable birth defects, mental retardation and other handicaps."

But those costs will go on future budgets.