(The New York Times News Service) -- Colorize your diet. That is the latest advice from nutrition experts who have studied the health-promoting properties of the vast spectrum of colorful fruits and vegetables now available throughout the country.

Two recently published books - "What Color Is Your Diet?" (Regan Books, $25), by Dr. David Heber, director of the Center for Human Nutrition at the University of California at Los Angeles, with Susan Bowerman, a dietitian, and "The Color Code" (Hyperion, $22.95), by Dr. James A. Joseph, Dr. Daniel A. Nadeau and Anne Underwood - emphasize the importance of increasing consumption of fruits and vegetables, and the need to choose broadly among the richly colored options.

This is not hard to do, and the payoff in terms of health - and weight - can be considerable. Nearly all fruits and vegetables are naturally very low in fat, replete with filling fiber and loaded with natural chemicals that can help protect against heart disease, cancer and age-related cognitive decline, cataracts and macular degeneration.

To me there is nothing more beautiful and tempting in a modern market than the expansive array of colorful produce, their vivid skins all the more enticing because of their health-promoting benefits. And even the paler members of this community - garlic, onions, leeks, cabbage, celery and the like - have notable health-promoting virtues.

Fruits and vegetables come closer than any other category of food to behaving like a fountain of youth. Each one is power-packed with plant-based chemicals, or phytonutrients, that can help to prevent or even reverse one or more chronic, debilitating and often deadly diseases.

For a detailed account of the protective chemicals nature has bestowed upon various fruits and vegetables and how these chemicals can help you as well as the plants they come in, consult "The Color Code." This book and "What Color Is Your Diet?" also provide tempting recipes to encourage an increased intake of produce, which should add up to nine or 10 servings a day. No doubt you have encountered government health experts' "five-a-day" campaign, currently achieved by at most a third of the population, and now I am saying double that, based on the findings that are coming in. If you check the Food Pyramid, you will see that five servings a day of fruits and vegetables is the bare minimum recommended to achieve a wholesome diet; nine servings or more are optimal for health maintenance.

But merely counting servings may not even be adequate if, these experts now say, you are missing out on one or more major color categories.

"Not all members of the fruit and vegetable group are alike," Heber says. "They have unique properties that provide combinations of substances with unique effects on human biology. Therefore, simply eating five servings a day of fruits and vegetables will not guarantee that you are eating enough of the different substances needed to stimulate the metabolic pathways of genes in the different organs where fruits and vegetables have their beneficial effects."

"Pigment power" is what it is all about, say the authors of "The Color Code," who divide fruits and vegetables into four broad color groups: red, orange-yellow, green and blue-purple, each with a different set of beneficial phytonutrients. Heber, who is more of a "splitter," groups them into seven color categories, as follows:

Red, including tomatoes (especially cooked tomato products), pink grapefruit and watermelon, which are rich in the carotenoid lycopene, a potent scavenger of gene-damaging free radicals that seems to protect against prostate cancer as well as heart and lung disease.

Red/purple, including red and blue grapes, blueberries, strawberries, beets, eggplant, red cabbage, red peppers, plums and red apples, which are loaded with powerful antioxidants called anthocyanins believed to delay cellular aging and help the heart by blocking the formation of blood clots. Heber includes red wine in this category.

Orange, including carrots, mangoes, cantaloupe, winter squash and sweet potatoes, rich in the cancer-fighter alpha carotene, along with beta carotene that protects the skin against free-radical damage and promotes repair of damaged DNA.

Orange/yellow, including oranges, peaches, papaya and nectarines, which provide beta cryptothanxin, which supports intracellular communication and may help prevent heart disease.

Yellow/green, including spinach, collards, corn, green peas, avocado and honeydew, which are sources of the carotenoids lutein and zeaxanthin. These are strongly linked to a reduced risk of cataracts and age-related macular degeneration, the leading cause of preventable blindness in developed countries.

Green, including broccoli, brussels sprouts, cabbage, kale and bok choy. These are rich in cancer-blocking chemicals like sulforaphane, isocyanate and indoles, which inhibit the action of carcinogens.

White/green, including garlic, onions, leeks, celery, asparagus, pears and green grapes. The onion family contains allicin, which has antitumor properties. Other foods in this group contain antioxidant flavonoids like quercetin and kaempferol. Heber includes white wine in this category.

The trick, these experts say, is to include as many plant-based colors in your daily diet as possible. In many cases, that means eating the colorful skins, the richest sources of protective phytonutrients, along with the paler flesh. So try to avoid peeling foods like apples, peaches and eggplant lest you lose their most concentrated source of beneficial chemicals.

Getting in 10 servings a day of produce is not that difficult, once you realize what a serving is. It is one medium apple, banana or orange, half a grapefruit, a quarter of a cantaloupe, a cup of raw leafy vegetables, half a cup of cooked or chopped raw vegetable or fruit and six ounces of fruit or vegetable juice.

If you start your day with juice, add fruit to your breakfast cereal, yogurt, pancakes or French toast; snack on whole fruit, fruit salad or vegetables like baby carrots; have a big salad with lunch or dinner; drink a vegetable or fruit juice before or with your meals; dine on main courses that include stir-fried, stewed, grilled or steamed vegetables and include fruit in your dessert, you will readily achieve and even surpass the 10-a-day goal without overdosing on calories. Heber has produced a revised version of the Food Pyramid, placing fruits and vegetables at the base, with grain-based foods above them.

My favorite home supper is a huge salad that typically includes spinach, richly colored lettuce, arugula, red pepper, avocado, asparagus and tomatoes, topped by a lean source of protein: slivered grilled chicken or turkey breast, pork, beef, salmon or tuna, cooked beans or a sliced hard-boiled egg. With a slice of whole-grain bread, a glass of vegetable juice or red wine and melon for dessert, I have got a full dinner and at least six of my day's produce servings.

Copyright 2002 The New York Times News Service. All rights reserved.