I've been using this for years. If you read the list of ingredients, you'll realize there's no way you're going to get all of that stuff by diet alone --- and these are things that are really good for you.
http://www.vitacost.com/garden-of-li...rmula-original
I mix it into my blender with frozen collard greens, spinach, broccolli and some bananas to neutralize the taste.
My mom has been green-juicing for years before it became a craze. I'm thinking about 25 or 30 years. She's 73 and looks like she's in her 50's....but that could be her genes also. I know it probably hasn't been hurting her to be putting greens in her body for all of this time.