I have been told by a dietician that we should all get at least two servings of fruit a day. So if you aren't already getting two fruits then start by eating at least one a day and build up to having two. Don't over do it on the fruit if you aren't use to eating it, because that could lead to some issues in the washroom. haha
Four ounces of pure fruit juice is one serving, so if you are having a large glass you are probably getting two servings. If you are not a big fruit eater, then you may want to start by adding a small glass of juice to your day to begin with, but do try to build up to eating two servings of raw fruit. Moderation and variety are the keys to success, so look for different ways to get your fruit, such as apple sauce, pure fruit juices (not punches or cocktails), compote, smoothies, salads and so forth.