Q: What all is included under green leafy vegatables and what is the method to healthily prepare them??

A: I use the term "green leafy vegetables" loosely since I simply want to encourage people to eat more vegetables in general. Any vegetable other than potatoes, yams, and corn should be eaten in virtually unlimited amounts by everyone -- they are that good for you and are light enough in calories that you become full sooner than you overeat. Potatoes, yams, and corn are not unhealthy, but are quite calorie-dense so they are easy to overeat and gain weight.

More specifically when I talk of green leafy vegetables I think of all sorts of lettuce, kale, spinach, chard, collard greens, cabbage, broccoli, cauliflower, green beans (not technically vegetables), and the like. Of course this doesn't mean that other vegetables or vegetables of other colors are not good either. As I said, there is virtually no such thing as an unhealthy vegetable.

How to prepare them is a very good and important question. Many of the leafy green variety, specifically lettuce and spinach can be eaten raw in a salad and should be eaten raw whenever possible -- this preserves all of their nutrition and is the best way to eat any fruits or vegetables if possible. Note that when making a salad it's very easy to overwhelm the healthy food with unhealthy dressings. Avoid commercial salad dressings and instead make your own from virgin olive oil, vinegar, lemon or lime juice, and whatever herbs and spices you like. Search on the web for homemade salad dressing recipes. Just watch portion sizes -- even though olive oil is healthy (at room temperature), it is extremely dense in calories so it's very easy to overeat it. Many meats, cheeses and nuts also go great with salads.

Obviously many vegetables like kale (not to mention things like potatoes) simply cannot be eaten raw. When eating them raw is not an option the next best method of preparing is steaming. If that's not an option, then boiling is fine too, though more of nutrients such as water-soluble vitamins B and C will be lost. Once you start using oils in cooking, then the level of health goes down. Sautéeing in a little oil can still be OK, but if you start using so much oil that it envelopes your food or using oil at high temperatures then you effectively turn a healthy food into junk. The rules of cooking with oil is to use as little as possible of it, at lowest possible temperature, and for shortest possible time.