"Without these meals, I'd live on toast and tea. or on nothing at all," said Mrs. Gertrude Hildemann, as she savored her steaming hot lunch of spaghetti and meat sauce, green beans, with a dessert of fresh fruit, which had been delivered to her a few moments before.

Mrs. Hildemann, who will be 85 in November, suffers from dizziness and weakness so severe that she is unable to shop or cook. She is one of about 225 elderly or ill people in suburban Virginia who depend on Meals on Wheels programs to deliver a hot lunch and cold supper to their homes each weekday.

This permits people temporarily or permanently unable to cook to continue living independently in their own homes. Many otherwise might have to enter nursing homes.

Nine separate Meals on Wheels programs cover the counties of Fairfax, Arlington and part of Prince William, as well as the cities of Alexandria and Falls Church. Mrs. Hildemann's meals, for instance, are prepared and delivered under the auspices of Meals of Wheels of Northern Virginia, which contracts for its food preparation with Northern Virginia Doctors' Hospital. Other programs do their own cooking or contract with private facilities.

Each Meals on Wheels plans menus with the help of a nutritionist.

All of the programs in the Virginia suburbs depend almost entirely on a corps of about 600 volunteers, who contribute time as food shoppers, packers, kitchen managers, administrators, drivers and visitors. The Northern Virginia Meals on Wheels, for insurance, relies on 50 church groups to provide workers on different days of the month.

Many volunteers are retired people who may be older than those they serve.

Teams of two volunteers load the meals into insulated boxes and then drive their routes, one person remaining in the car while the other personally delivers the meals.

Instructions for volunteers are never to leave a door unanswered. If there is no answer after repeated efforts, volunteers then report this to their coordinator, who will determine the problem even if it means calling the police to check into the situation.

Relationships between volunteers and those they serve are often very warm. Along with Mrs. Hildemann's meal, for instance, came a bag of home-baked blueberry muffins and a bouquet of roses, both presents from her volunteer visitor.

"Our volunteers and clients do get attached to each other." says Mrs. Glorida Gibson, founder of the Northern Virginia program. "If their driving routes get changed, volunteers get upset and quickly arrange to have their regular clients back on their routes," adds Mrs. Gibson, who in addition to helping coordinate the program, occasionally treats herself to the pleasure of driving and delivering meals.

Often people take home-delivered meals for a short time during convalescence from an illness or hospitalization. For some elderly people, meals on Wheels is the only daily contact with the outside world.

The original idea of home-delivered meals reaches back to London during World War II, when it was found that many elderly people were living in bombed - out quarters unable to shop and cook, and also unable to get to the communal soup kitchens which had been set up. Prepared meals had to be driven to them on a daily basis. The idea spread to the United States in 1954, when a program began in Philadelphia. By the late 1960s, meals on Wheels had begun throughout the country.

The cost of five hot and five cold meals in suburban Virginia ranges from $10.00 to $12.50.

People unable to pay the full cost may use food stamps to do so. In addition, federal nutrition funds provided by the Older Americans Act help pay for some clients on a limited basis.

The combination of volunteer help, individual contributions and federal funds makes the Virginia programs self-sustaining. Others around the country are less fortunate, particularly in some inner - city and rural areas.

Meanwhile, at least for Mrs. Hildemann, who has no relatives in the Washington area. "Meals on Wheels makes it possible to continue living in my own home. To me, this is wonderful."

Information and Referral Service: -- Visiting Nurse Association, 5055 S. Chesterfield Dr., Arlington, Va. 22206, 671-1228.

Alexandria Meals on Wheels. 3606 Seminary Rd., Alexandria, Va. 22304, 751-9866.

Franconia Meals on Wheels, 5916 Bush Hill Dr., Alexandria, Va. 22310,971-4072.

Manassas Meals on Wheels, 8623 Weems Rd., Manassas, Va. 22110, (703) 368-5507.

Mt. Vernon Meals on Wheels, 1120 Morningside Dr., Alexandria, Va. 22308, 768-7920.

Meals on Wheels of Northern Virginia (covers Annandale, McLean, Arlington, Falls Church). Northern Va. Doctor's Hospital, 601 Carlyn Springs Rd., Arlington, Va. 671-1228.

Reston-Herndon Meals on Wheels, St. Thomas a Becket Catholic Church, 1421 Wiehle Ave., Reston, Va. 22090, 860-2115.

Spring field Meals on Wheels (ECHO), 5315 Garner St., Springfield, Va. 22151. 941-4806.

Vienna-Dun Loring-Oakton Meals on Wheels, 2201 Tott Avenue, Vienna, Va. 2n Wheels, Box 41, Fairfax, Va. 22030, 273-4827.