Unless you've been locked up in a steak house for the last decade, you've been bombarded with the message that eating more fruits and vegetables will help you lose weight.

Now researchers suggest you'll not only save calories, you'll build your body's defense mechanisms if you include more produce in your meals. The U.S. Department of Agriculture has created a score sheet that rates foods on their potential to protect your body from oxidative damage.

Overall, prunes rank highest in the test-tube experiment. Other potent fruits include raisins, blueberries (highest among the fresh fruit), blackberries, strawberries, raspberries, plums and oranges, in that order.

Kale is the leader in the vegetable category, followed by spinach, Brussels sprouts, alfalfa sprouts, broccoli flowers, beets and red bell peppers.

Don't focus on the top scores alone, says Ronald Prior, who is with the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. Fruits and vegetables have a whole complement of chemicals that may be disease fighters.

Besides, you eat by taste, not by numbers.

And you'll find such delicious variety in fruit and vegetable-based dishes, staying on a highly nutritious weight-loss diet won't be a challenge.

Kale, for example, adds a lot of punch to summer soups, casseroles and stews.

"It looks good and it provides a lot of nutrition," said David Hirsch, one of the co-owners of the Moosewood Restaurant cooperative in Ithaca, N.Y. and co-author of "Moosewood Daily Special".

His personal preference is red Russian kale which is milder tasting and has a more tender texture. You can identify it by the flatter, less curly leaves and the stems that have a slight violet color.

"We use kale in a vegetarian version of white bean and kale soup, substituting sun-dried tomatoes for sausage.

"You can steam kale and serve it with a splash of herb or wine vinegar or a little bit of extra virgin olive oil or sesame oil, or you can saute it with olive oil, garlic and crushed red pepper flakes. Sauteing will give the greens a more appealing texture," said Hirsch.

At the restaurant, cooks serve a rotating selection of kale; spinach dressed with sesame oil and Swiss chard. Kale salad is new on the menu. It's combination of sauteed kale, red onions and corn.

But you don't have to scrap your personal favorites to get more high-antioxidant produce into your diet.

"One thing people can do is incorporate more fruits and vegetables into foods they normally eat," said Penny Kris-Etherton, nutrition professor at Penn State University in University Park.

Though health experts are campaigning to get you to eat five servings of fruits and vegetables a day, you'll get more protective benefits if you double that, according to Kris-Etherton.

She suggests looking for ways to add fruits and vegetables to everything you eat.

"I eat oatmeal for breakfast and add a single-serving carton of applesauce and a half a banana. It's an exciting blend of flavors," she said.

Her favorite sandwich is mesquite-grilled turkey breast topped with roasted red peppers and a couple of asparagus spears. She sprinkles raisins, different kinds of onion slices and mushrooms on buffet salads.

Kris-Etherton also recommends you substitute vegetables for some of the meat in your favorite recipe. If you substitute a small chopped red bell pepper (32 calories), for just two ounces of ground beef (132 calories) in a spaghetti sauce you'll save 100 calories and get the pepper's nutrients.

You can also make healthier choices in your desserts. Opt for a fruit tart instead of the pecan pie, Kris-Etherton said.

Here is a powerhouse variation of the professor's favorite sandwich.

Grilled Chicken and Red Pepper Sandwiches

2 boneless, skinless chicken breast halves
2 tablespoons lemon juice
2 tablespoons orange juice
2 tablespoons sodium-reduced teriyaki sauce
2 tablespoons honey mustard
4 slices onion-rye or similar bread
1 roasted red bell pepper, cored, seeded and cut into quarters
1 cup baby spinach leaves

Place chicken breasts between two sheets of wax paper. Pound to flatten to an even 1/2-inch thickness. Place in a shallow bowl. In a cup stir together lemon and orange juices, teriyaki sauce, oregano and olive oil. Brush over chicken breasts. Marinate at room temperature 15 minutes or in refrigerator 1 hour.

Grill chicken over ash-covered coals or in stove-top grill pan, allowing about 3 to 5 minutes per side.

Spread 1 tablespoon mustard on each of 2 bread slices. Arrange half the spinach leaves over mustard-topped bread. Add chicken breast and top with half the red pepper. Cover with remaining bread slices. Serves 2.

Each serving has: 360 calories; 5 grams fat; 35 grams protein; 146 milligrams cholesterol; 33 grams carbohydrates; 1050 milligrams sodium and 2.5 grams dietary fiber.