Is there a specific diet for fibromyalgia?

Whole food. The best diet is a whole food diet. Vegetables, fruits, lean proteins, whole grains, nuts, legumes, and omega 3 fatty acids. Avoid processed foods, food additives, aspartame, and too much caffeine. Some people may have food sensitivities that increase their symptoms. The most common foods are gluten, dairy, eggs, shellfish, and nightshade vegetables (peppers, eggplant, tomatoes, potatoes).
Many. There are many different diets for people with fms. Some researches feel a low gluten diet is helpful. Others say a diet low in saliscilates is helpful. You need to do trial and error. There are a lot of good books with different suggestions.