Welcome to the concept of "mono meals."

Mono meals are popular among raw foodists -- people who eat diets that consist primarily of uncooked plant foods -- and some vegetarians.

I fondly recall one evening a few years ago sitting across the table from a friend, Karl, who was chomping away -- one by one -- on long green beans he had steamed and piled into a big bowl. He'd bought them at a nearby farmers market. Karl told me he often ate dinners such as these. They were easy to prepare, and there was little mess to clean up, he said.

It was easy to see those advantages.

But is it a healthy way to eat?

We hear a lot about the importance of variety in our diets. A varied diet -- especially one that includes plenty of fruits, vegetables, whole grains, beans, nuts and seeds -- helps ensure that we get the full spectrum of vitamins, minerals and other nutrients we need to support health.

But eating a varied diet doesn't mean each individual meal must include a wide range of foods. Instead, variety can come by what you choose on a daily, or even weekly, basis.

And there can be advantages at times to eating meals made up of only one or two foods. That's especially true when the meals consist of fruits and vegetables.

I've seen mono meals in practice at vegetarian nutrition conferences. Once, my family accompanied me to one of these events, and one attendee drew wide-eyed stares from the kids when he passed our lunch table carrying a cafeteria tray heaped high with nothing but purple plums. Another sat down at our table with the equivalent of an entire watermelon cut into slabs.

Both of these people were thin, fit and happy.

Mono mealers have told me they're taking a cue from nature in which most animals eat mono meals. They also say that by focusing on only one food, rather than many, they have a better sense of how much they really need to eat and resist the tendency to overeat.

Think about the last time you ate at a restaurant buffet or Thanksgiving dinner. How much did you eat? Compare that to the amount you'd likely eat if your choices were unlimited amounts of carrots or fresh orange slices.

If you wanted to try some mono meals, there's no better time of year as fresh, seasonal fruits and vegetables are becoming plentiful. We'll soon be able to find strawberries, blueberries, melons, green beans, salad greens, bell peppers and tomatoes, for example, at the farmers market and roadside stands.

These foods are relatively low in calories, high in fiber, and full of important nutrients. They're also devoid of saturated fat, trans fat and cholesterol. Eating these foods often and in ample amounts makes good sense. They're filling and good for you.

Of course, a steady diet of mono meals may not be realistic for many people. For example, some people, including those with diabetes, may need a more carefully controlled mix of nutrients with their meals.

But for most of us, it's worth considering eating several mono meals of seasonal, locally grown fruits and vegetables each week from now through the end of the summer.

If you try it, prepare for some stares.