Parents often ask me if certain food may make the ADHD symptoms of their children worse. One of the purported culprit is sugar and the "sugar rush" phenomenon is well known. Despite a lack of studies to support these claims, anecdotal reports are aplenty.
In this news article a mother reports success with diet changes such as adding vitamins and omega 3's, avoiding addatives- red dyes in particular and skipping the simple processed sugars.
Read about symptoms of ADHD here.