One of the diets many people, including myself, use for fibromyalgia is composed of vegetables, fruit, whole grains, lean meats, and low fat dairy. This type of diet is designed to keep energy levels high. It also may help you lose weight which my help the fibromyalgia symptoms.
Ideally you are eating high protein, low fat meals with regular snacks in between. The snacks should be high fiber and/or fruit, but no more than 100 calories. In this way you are actually eating six times a day. This also keeps your blood sugar smoother throughout the day. You want to make sure you do not get overly hungry.
Many people with fibromyalgia also find that it is beneficial for them to eliminate certain preservatives or additives from their diet. Two of those additives are MSG and nitrates. You will find these in hot dogs, bacon, and of course Chinese foods. Read the labels. I was very surprised at how many foods I found with MSG in it.
A sweetener that some people with fibromyalgia have problems with is aspartame. Some people find a certain amount of relief when they eliminate this sweetener. It may be worth a try when you are trying to take off the edge of your pain.
Another sweetener that gives some people problems is sugar. Sugar in some shape or form seems to be in everything. At least try to eliminate it from snacks and candy.