There's no such thing as a bad-for-you vegetable.
Sure, some are better for you than others. The most flamboyant - the ones that are brightly colored red, orange and dark green, for example - are usually richest in nutrient content.
Good examples of the all-stars are broccoli, kale, tomatoes, carrots, sweet potatoes, green peppers and acorn squash, to name a few. They provide copious quantities of iron, calcium, vitamins A and C, folic acid, potassium and other nutrients.
But all vegetables contribute something to your health, even if it's nothing more than some dietary fiber and a smattering of trace minerals and vitamins. And unless you slather them with butter or dose them with salt or cheese sauce, fresh vegetables are low in calories, free of saturated fat and cholesterol and very low in sodium.
Topping the list of vegetables that are less endowed are the less colorful varieties. They include iceberg lettuce, celery, cucumbers, mushrooms, green onions, eggplant and others. It's not that these veggies are nutritional zeros, but they are not nutrient-packed.
And that's OK.
Everything you eat does not have to be a concentrated source of nutrients. Here are some of the ways that these less nutrient-packed choices can add value to your diet:
• They add low-cal bulk. The added benefit is that at the same time, they may also displace higher-calorie foods from your diet.
So adding a green salad to a meal may encourage you to eat less of a fattier entrée. Because they're mostly composed of water, these veggies contribute to your hydration, too.
• They add variety and interest. Mushrooms and onions add flavor to foods, and cucumbers and celery add a pleasant aroma and crunch.
• They do have nutritional value. They're not nutritional zeros.
Onions contain some vitamin C, and celery contains vitamin A. They both contribute folic acid and potassium.
Also note that just because a vegetable lacks color, it doesn't necessarily mean it lacks nutrients. Some white vegetables - cauliflower and daikon radish are good examples - rank right up there with their colorful cousins in terms of nutritional value.
So remember: When it comes to vegetables, there's no bad choice. Eat more of them more often.
Suzanne Havala Hobbs is a registered dietitian and clinical associate professor of health policy and management at UNC-Chapel Hill. Reach her at firstname.lastname@example.org; follow her on Twitter, @suzannehobbs.