For many of us, that was a litany of childhood, an 11th commandment — often followed by "or no dessert." I even know a mother who tried reverse psychology on her son — "You can't have your vegetables until you've finished your meat" (or chicken or fish) — though I can't testify to its success.

As evidence of the health benefits of vegetables has accumulated, public health scientists, nutritionists, federal health experts, growers and marketers, teachers and physicians have been urging — and urging and urging — that Americans eat more of them.

Producers have gone to great lengths to encourage vegetable consumption by a public increasingly pressed for time and overly focused on fast food and takeout. Farmers' markets are springing up all over the country, with enticing displays of locally grown produce. Supermarkets feature ready-to-eat and ready-to-cook vegetables — spinach, salad greens, complete salads, broccoli florets, peeled baby carrots. Simple, tasty recipes are often part of the produce display. Even the major fast-food purveyors have made an effort, introducing salads as side and main dishes; McDonald's now sells more salads than any other eating establishment.

Yet last month came the discouraging word from the national Centers for Disease Control and Prevention that Americans have fallen far short of the goals set a decade ago to increase consumption of vegetables. In 2009, just 26 percent of adults had three or more servings a day (including those who count a tomato slice and a lettuce leaf on a burger as a vegetable serving). That was half the percentage public health officials had hoped for.

And it falls even shorter if you look at the current recommendations: at least four to five vegetable servings daily. Please note the definition of a serving: half a cup of cut-up or cooked vegetables, one cup of fresh greens, half a cup of cooked dried beans, or, if you must, six ounces of vegetable juice.

So what's so good about vegetables anyway? First, vegetables are loaded with vital nutrients: potassium, beta-carotene (the precursor of vitamin A), magnesium, calcium, iron, folate (a B vitamin) and vitamins C, E and K, as well as antioxidants and fiber. Despite an ill-conceived effort years ago to "package" vegetables' nutrients in a supplement, there is no good way to consume them short of eating the foods that contain them.

And unless they are drowned in butter or a high-calorie sauce or dressing, vegetables provide those nutrients at minimal caloric cost, an important attribute in a society where obesity is ballooning out of control.

Curbing weight gain can reduce the risk of Type 2 diabetes, now rampant in America and an important cause of heart disease, kidney failure and premature death.

Fiber, Potassium and More

Vegetables provide dietary bulk, filling the stomach and reducing the appetite for higher-calorie foods. The fiber in vegetables helps reduce blood levels of heart-damaging cholesterol and is a major antidote for constipation and diverticulosis.

The potassium in tomato products, dried beans, sweet potatoes, spinach, Swiss chard and winter squash can ease high blood pressure, a major risk factor for heart disease and stroke, and may also reduce the risk of developing kidney stones and bone loss.

Folate is a critical nutrient during pregnancy to prevent spinal cord defects; it also helps the body form red blood cells. Vitamin E, an antioxidant, protects against the deterioration of essential fatty acids and premature cell aging, and vitamin C is important for healthy gums and teeth, healing of wounds and absorption of iron. Vitamin K aids in blood clotting (note, however, that people taking blood thinners must curb their intake of foods rich in this nutrient).

The vitamin A formed from beta-carotene is vital to the health of the eyes and skin and may help prevent infections. A Harvard study of 73,000 nurses, published in 2003 in The American Journal of Clinical Nutrition, linked a carotenoid-rich diet to a reduced risk of coronary artery disease, and a Swedish study found that it cut the risk of stomach cancer in half.

Two other carotenoids, lutein and zeaxanthin, can reduce the risks of macular degeneration and cataracts, common causes of vision loss as people age. These nutrients are found in dark green leafy vegetables, like spinach and kale, which are packed with other valuable vitamins and minerals.

Lycopene, another carotenoid, may reduce the risk of prostate cancer and was also linked to a reduced risk of cardiovascular disease in women. Lycopene is best obtained from processed tomato products. (Tomatoes, of course, are technically fruits, as are squash and other "vegetables" with seeds. The foods we usually think of as fruit have plenty of nutritional value but tend to have more calories than vegetables — and may not supply all the same nutrients.)

Several other vegetables, not all of them popular among Americans, have also been linked to protection against cancer. These are the so-called cruciferous vegetables: broccoli, cauliflower, cabbage, kale, collard greens and brussels sprouts.

Then there are the allium vegetables, onions and garlic, that researchers in Milan have linked to protection against cancers of the colon and rectum, ovary, prostate, breast, kidney, esophagus, mouth and throat.

Last year The Nutrition Action Healthletter, published by the Center for Science in the Public Interest, an advocacy group based in Washington, ranked vegetables according to nutrient content. Kale led the list, followed by spinach, collard greens, turnip greens, Swiss chard, canned pumpkin, mustard greens, sweet potato, broccoli and carrots.

Others among the "superstars" listed were romaine lettuce, red bell pepper, curly endive, brussels sprouts, butternut squash, green pepper, peas and bok choy.

Except for sweet potato (100 calories in one medium potato) and peas (70 calories per half cup), none of these (when unadorned by fat) have more than 40 calories a serving, and most have only 20 or 30 calories.

Suggestions Welcome

Given that so many professionals have failed to raise the consumption of vegetables among not-so-health-conscious Americans, how can we make a difference? Fresh ideas are needed, and I invite readers to e-mail suggestions to [email protected] for possible inclusion in a future column. (Please include the word "Brody" in the subject line.)

Who knows? One of you may succeed in keeping Americans healthier and curbing our runaway health care costs.