Fast foods, sodas, and ice cream may be kids' favorite menu items, but they're also probably the worst for those with attention deficit-hyperactivity disorder (ADHD), a new literature review suggests. According to many researchers, a relatively simple diet low in fats and high in whole grains, fruits, and vegetables is one of the best alternatives to drug therapy for ADHD. Omega-3 and omega-6 fatty acid supplements have also been shown to help in some controlled studies, they noted.