If you are looking for high nutritional value, low calories, and taste, consider green beans. A cup of green beans -- I suppose this is unseasoned -- has less than 45 calories. Green beans are a rich source of Vitamins A, C, and, especially K, also potassium, manganese, dietary fiber, iron, and folate. They serve as a good source of niacin, omega-3 fatty acids, protein, calcium, phosphorus, copper, thiamin, riboflavin, and magnesium.
I'm not sure I even need all that stuff.
For those concerned about cholesterol and arteriosclerosis, the beta-carotene form of Vitamin A along with the Vitamin C in green beans are antioxidants, fat and water-soluble respectively, that help block the oxidation of cholesterol, preventing it from adhering to the walls of blood vessels.
I think the best way to have green beans is to grow them yourself. Almost nothing is easier to grow. Beans don't need a lot of space or particularly good soil. If you want to learn how to can in a pressure cooker, canning your very own green beans is a good place to start. Ten pounds of pressure for 25 minutes is the recommendation for quart jars. If the seal is good, canned beans will easily keep for a couple of seasons.
There are many varieties of green beans. My wife has always been a fan of golden wax bush beans because they are different. I think they do have a milder flavor and make a more "decorative" plate for some meals. We always grew bush beans when I was a kid on the farm because we had plenty of space, and bush beans tend to come on all together and don't require structure. Bush beans are the way to go for large-scale commercial operations, but as I have grown older, I have become an advocate for pole beans. My back appreciates them.
When I possible, I like to plant in three-sisters fashion -- first corn, then pole beans, followed by some kind of winter squash. I didn't do that this year because of timing issues due to family health problems. I've lost some of my small patch of corn to deer and dogs running through and breaking off corn stalks. That does not happen as much when pole beans are present to provide extra support and strength. Kentucky Wonder pole beans are what I usually use for the three-sisters, because they are an heirloom variety and are not bad as dried beans. They are rust-resistant and develop strings as they mature.
If you are short on garden space, pole beans will help out. They require much less horizontal room to grow and, as I mentioned, are less demanding on an old man's back to harvest. I use a couple of 16-foot welded-wire cattle panels -- it's bigger than 9-gauge, maybe 6-gauge -- with three or four steel posts to hold the panels for my beans to climb. This year I set the panels up in the middle of a bed 4 feet wide and 32 feet long. I planted Kentucky Wonders -- since that is what I had on hand -- on both sides of the panels. This arrangement allows for very convenient harvesting without nearly so much bending. With a midget grandkid or two to help, no bending is involved.
Despite the late start, we have already filled a couple of canners in addition to eating fresh beans for dinner or supper every day lately. I fully expect to have an adequate supply of green beans canned for winter before the planting is exhausted. After all, I still have beans in the pantry from late year's harvest.
Blue Lake pole beans probably have a better flavor than Kentucky Wonders as green beans, but I don't really have any complaints. I try to pick them before the strings develop so they are easy to snap, and they are tasty enough for me. Those of Scottish descent, like myself, tend to not care so much about what we eat as long as there is plenty.
If a person is going to figure on feeding himself, growing beans of one kind or another is a good place to start.