The ADHD rating scale (RS) will be the principal behavioral outcome measure. We hypothesize that children on restriction diet will have significantly lower ADHD RS scores after 5 weeks relative to the Ruse diet group. In addition children will undergo functional magnetic resonance imaging (fMRI) at baseline and again at 5 weeks. Children will perform a flanker task known to engage the dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC) during attention tasks. The children will also perform will look at pictures of appealing and unappealing food and rate whether they would like to eat it or not. This task is known to activate the ventral striatum (VS) (reward processing). A secondary hypothesis is whether children on the restricted diet will show changes in activity and connectivity of areas (DLPFC, ACC, VS) relative to those on the Ruse diet.