SEVERAL nutrition education programs at the Department of Agriculture are in jepoardy, standing squarely in the path of the Reagan administration's 1984 budget ax. Administration officials believe the cuts are necessary in view of increasing budget constraints.

The following activities are on the endangered list:

* The Nutrition Education and Training (NET) program would be eliminated in 1984. The program, funded at $5 million this year, is operated by the states and teaches school children, teachers and school food service personnel about food, nutrition and good eating habits.

Consumer and nutrition groups can be expected to fight the proposed elimination. Robert Leard, acting food and nutrition service administrator says there were never plans for the program "to go on forever," adding, "It's a very small program, it's done its duty over the years, and if states want to continue it, now is the time." In its budget presentation, USDA says the program is being eliminated because its mandate, the development of curriculum materials, has been fulfilled.

However, Elizabeth Shipley-Moses, public policy coordinator for a professional group, the Society for Nutrition Education (SNE), argues that the program "is much more than curriculum development." She says the program has turned school cafeterias into learning centers and has been cost-effective, reducing plate waste because of improvements in meal management by food service workers.

* The Expanded Food and Nutrition Education Program (EFNEP), operated through Extension Service grants to states, would be cut 42 percent, from $60 million in 1983 to $35 million in 1984. The program provides for trained aides to work one-on-one with low-income families, especially those with young children, to teach them how to plan healthy meals on a limited budget.

EFNEP is popular in Congress and with the states, and a previous attempt to shift federal funds from the program failed. The proposed cut comes on the heels of a congressionally mandated evaluation that gave the program high marks for effectively targeting the neediest families and for keeping program goals in sharp focus.

In the budget proposal, USDA says EFNEP funding will permit states the flexibility to maintain the program by "using other available funds."

* Funding for the Human Nutrition Information Service (HNIS), the USDA agency responsible for collecting data on nutrient content in foods, conducting periodic nationwide surveys of what people eat, sponsoring nutrition education research and providing nutrition information and library services to the public, would be cut 20 percent, from $8.2 million this year to $6.6 million in l984.

The service was saved from a more devastating blow by concerned nutrition groups which, last fall, got wind that the Office of Management and Budget was planning to cut the agency's budget in half and its staff of 85 by more than one-third. In December, the Society for Nutrition Education (SNE) sent a letter to OMB complaining that the cuts were short-sighted since, the group said, both private and public sector agencies and groups depend on the HNIS nutrition surveys and data for program planning. SNE and the National Nutrition Consortium, a group of six major scientific and educational nutrition associations, also issued a press release charging the government with "abandoning nutrition."

Assistant Secretary of Agriculture Mary Jarratt, who oversees the nutrition service, said recently the 20 percent cut would permit work to continue on the consumption survey and data bank. But other HNIS activities would have to be postponed, she said.

"USDA has made a very systematic effort, practically since day one, to demolish education programs," charged Michael Jacobson of the Center for Science in the Public Interest. He said Secretary of Agriculture John Block has ignored requests to meet with consumer groups, and he complained about the administration's decision to cease publication of certain nutrition pamphlets and charge what he characterized as outrageous prices for others.

Not all nutrition education activities at USDA are imperiled, however. In line with the department's efforts to work with private-sector groups on nutrition education projects, USDA is planning a multifaceted "Food and Fitness" campaign.

To be funded in large part by groups that represent producers of commodities such as meat, egg and dairy products, the campaign will officially begin in May with a "commodity fair" on the Mall. USDA's coordinator for the program, George Trapp, says the theme of the fair will be, "Try a new food today," and will attempt to broaden people's awareness of the variety of food produced by American farmers.

Trapp was unable to estimate USDA costs for the campaign, which will include production of a documentary, publications and regional commodity fairs. Plans for other activities are still being worked out, Trapp said.

Not surprisingly, the U.S. dietary guidelines won't be used in the campaign. Commodity groups have opposed the set of nutrition recommendations, which advocate less fat and cholesterol in the diet. "The program is not designed to be a prescription like that," says Trapp. Contending that "there's no one answer that's right for everyone," Trapp said the aim of the program is to raise people's awareness about the kinds of food they are eating and the level of physical activity they are getting. However, there will be nutrition messages targeted to particular groups of people, he says, including pregnant women, grade school children, teen-agers, adult men and women, and older Americans.