How effective is the Feingold diet for ADHD?

The Feingold diet is best described as a mixed bag. Whereas the diet’s proponents vehemently support it, pointing to a 50 percent success rate, its opponents say it has never been proven scientifically. Either way, the diet is rigorous for a young child. It involves giving up all foods with artificial coloring, artificial flavoring, artificial sweeteners and preservatives.