for single cooks, that is. This is not a soup advertisement, nor is it a recommendation to spend the next three hours hovering over a pot of simmering stock.

Good soups for single cooks are quick soups, soups that take 30 minutes or less to prepare but that include fresh and lively ingredients. With a thick slice of crusty bread or toasted pita one night, a salad the next or with a sandwich two days later, a quick soup can stretch into several meals.

Besides being a dependable lunch or dinner to come home to, soup can be a helpful diet aid. According to "Jane Brody's Good Food Book" (Norton, $19.95), there are a few studies indicating that frequent soup eaters are more successful at losing and keeping off weight than nonsoup eaters. It's not that soup helps burn calories, but rather that it limits the amount of food you eventually eat. In addition, says Brody, soup has a lower caloric density than most solid foods and takes a relatively long time to consume.

Of course, a 30-minute time frame eliminates long-cooking hearty soups, such as lentil or split pea, and it does not include time for making stock, the heart of any soup. But if you're not prone to cooking up a healthful pot of vegetables or chicken or beef bones over the weekend and freezing the homemade stock (invaluable for use in other dishes as well as quick soups), there are ways to manipulate canned broths, which can have up to a whopping 1,000 milligrams of sodium per cup. (The estimated safe and adequate dietary intake for sodium as recommended by the National Academy of Sciences is between 1,100 and 3,300 milligrams per day.)

An obvious alternative is to use low-sodium bouillon, which contains a great deal less sodium than regular bouillon or canned stock. A cup of Borden's Lite Line low-sodium chicken bouillon, for example, contains five milligrams of sodium, versus 900 milligrams of sodium per cup of Borden's regular bouillon. Swanson's canned chicken stock contains 910 milligrams of sodium per cup.

If the soup recipe has enough additional spices, the taste shouldn't suffer greatly, and you can always go heavy on the freshly ground black pepper. Or, you might try using half low-sodium bouillon and half regular stock.

As for low-sodium canned stock, Pritikin Foods makes a defatted chicken stock that contains 175 milligrams of sodium per serving and no fat. It is available at the Low-Sodium Pantry in Bethesda, which sells a variety of other canned low-sodium stocks. Health food stores are also good sources for low-sodium canned stocks. And Giant's Someplace Special in McLean sells homemade salt-free chicken stock for $2.75 a quart.

If using regular canned stock, try halving the sodium by diluting the broth with an equal amount of water. Then, to bring new life into the stock and water, add chopped, fresh vegetables and cook for 15 minutes. Or, to shave some time off, add the vegetables to the soup while it cooks with the other ingredients and either discard them or keep them in the finished soup. The addition of vegetables is a good trick to refresh low-sodium stocks as well.

And just as homemade stock should be refrigerated and skimmed of its fat, canned beef and chicken broth can also be refrigerated and skimmed.

It seems like a natural for fish shops to cook up a batch of discarded fish bones and sell it as stock, but it's hard to find. As for commercial fish stocks, possibilities include Knorr-Swiss' fish bouillon or Saucier's frozen fish stock, which can be purchased at specialty shops and in the gourmet section of some supermarkets. Some specialty food shops, such as Sutton Place Gourmet and Giant's Someplace Special, will prepare fish stock if you give them 24 hours' notice.

Here are some quick soups and quick accompaniment suggestions to help make life easier -- and possibly skinnier. CURRIED CREAM OF ANY VEGETABLE SOUP (4 to 6 servings)

1 tablespoon butter or margarine

1 small onion, chopped

1 clove garlic, minced

2 tablespoons curry powder

4 cups chicken stock

2 1/2 cups of any vegetable or a mixture: diced butternut or yellow squash; carrots, thinly sliced; chopped broccoli or cauliflower; diced potatoes or 2 10-ounce packages frozen peas

2 cups plain yogurt

1 green apple, peeled and chopped (optional)

Melt the butter in a stockpot. Add the onion and garlic and saute' over medium heat until onion softens, about 3 minutes. Add the curry powder and continue cooking for another 2 minutes, stirring constantly so that the curry does not burn.

Add the chicken stock and vegetables and bring to a boil. Lower the heat and simmer for about 20 minutes, or until vegetables are soft.

In batches, pure'e the soup in a food processor or blender. (You can eliminate pure'eing one batch, if you like chunks of vegetables in your soup.) Return soup to pot, add yogurt and cook over low heat, stirring, just until soup is hot. Pour into soup bowl and garnish with optional chopped apple. Serve with afghan bread (available at local supermarkets). CHUNKY CHICKEN AND PASTA SOUP (5 to 6 servings)

2 tablespoons olive oil or more if needed

2 boneless, skinless chicken breast halves, cut into 1/2-inch cubes

1 large onion, finely chopped

1 red bell pepper, diced (substitute green bell pepper)

1 garlic clove, minced

3 1/2 cups chicken stock or broth

16-ounce can tomatoes (preferably Italian-style plum), including juice

1/4 cup finely chopped fresh parsley

3/4 teaspoon dried basil

Scant 1/2 teaspoon dried oregano leaves

1 bay leaf

1/4 teaspoon freshly ground black pepper

2 ounces vermicelli or thin spaghetti, broken into 2-inch lengths (about 1 cup)

In a dutch oven or very large saucepan, combine 2 tablespoons of oil and the chicken. Cook over medium-high heat, stirring frequently, until the chicken is cooked through. With a slotted spoon, remove the chicken from the pan and reserve it in a small bowl. Add the onion, red or green pepper and garlic to the pan. Cook, stirring frequently, until the onion is very tender. If necessary, add a bit more oil to the pan to keep the vegetables from sticking.

Add the stock and tomatoes, breaking up the tomatoes with a large spoon. Return the chicken to the pan. Add the parsley, basil, oregano, bay leaf and black pepper. Stir to mix well. Lower the heat and simmer the soup, covered, for 5 minutes. Raise the heat so the soup boils. Add the pasta. Lower the heat again and boil gently, covered, for 12 to 17 minutes, or until the pasta is tender; stir occassionally. Discard the bay leaf and serve. From "Soup's On," by Nancy Baggett and Ruth Glick (MacMillan, $16. 95) SCALLOP CHOWDER WITH PARMESAN (4 to 6 servings)

2 tablespoons butter

1 medium onion, peeled and chopped

1 1/2 cups sliced mushrooms

2 potatoes, peeled and diced

4 cups fish stock or bottled clam juice

1 cup lowfat milk

3 tablespoons dry sherry or white wine

Hot pepper sauce to taste

1/2 cup grated parmesan plus additional for sprinkling

2 tablespoons cornstarch

1/4 cup water

3/4 pound bay scallops

In a large saucepan, melt the butter. Add onion and mushrooms and cook over low heat for about 5 minutes. Add fish stock or clam juice and potatoes and bring to a boil over high heat. Cover and simmer for about 20 minutes, or until potatoes are done.

Stir in the milk, sherry, hot pepper sauce and parmesan. Dissolve cornstarch in water and stir slowly into soup. Cook over medium heat for about 2 or 3 minutes, stirring, then add scallops and cook for about another 4 minutes, or until soup is thickened and scallops are cooked. Serve with oyster crackers and pass additional parmesan, if desired. DILLED CARROT BISQUE (3 servings)

2 cups chicken broth, preferably low-sodium

2 cups sliced carrots

1/4 cup chopped fresh parsley

2 tablespoons chopped shallots

1 garlic clove, minced

1/2 teaspoon dill weed

1/8 teaspoon pepper

1/2 cup skim milk

In medium saucepan over medium-high heat, add chicken broth, carrots, parsley, shallots, garlic, dill weed and pepper; bring to a boil. Reduce heat, cover. Simmer about 20 minutes, or until carrots are tender.

In covered blender or food processor at medium speed, blend the mixture until smooth. Return to saucepan; stir in milk and heat about 1 minute. Do not boil. From "Heart Smart," by Gail L. Becker (Fireside, $5.95) MEXICAN ZUCCHINI SOUP (4 servings)

1 small onion, chopped

1 1/2 teaspoons butter or margarine

2 cups chicken or vegetable broth

10 ounces zucchini, unpeeled and diced

1 1/2 cups corn kernels

2 tablespoons finely chopped green chilies or jalapeno peppers (fresh or canned)

1/2 teaspoon salt (optional)

1/8 teaspoon freshly ground black pepper

1 cup lowfat or skim milk

2 ounces monterey jack cheese, cut into 1/4-inch cubes

Minced freshly parsley and ground nutmeg for garnish

In a large saucepan, saute' the onion in the butter or margarine until it is tender, about 3 minutes.

Stir in the broth, zucchini, corn, chilies, salt and pepper. Bring the soup to a boil, reduce the heat, cover the pan and cook the soup until the zucchini is tender, about 5 minutes.

Stir in the milk and heat the soup until it is hot but not boiling. Remove the soup from the heat and stir in the cheese. Garnish the soup with parsley and nutmeg.

Serve with quick, nutritious tortilla chips: Stack soft corn tortillas, cut them like a pie into 8 wedge-shaped pieces each and spread the pieces on a lightly greased or nonstick baking sheet. Bake them at 350 degrees for 10 minutes or until they are crisp and lightly golden. From "Jane Brody's Good Food Book," by Jane E. Brody (Norton, $19.95).