A new study warns an unhealthy diet during pregnancy could influence a child's risk of attention-deficit/hyperactivity disorder or ADHD. Researchers found that a high-fat, high-sugar diet can affect the function of a gene called IGF2. The gene helps steer fetal development of brain regions previously linked to ADHD. Senior researcher Edward Barker, director of the developmental psychopathology lab at King's College London, said "These results suggest that promoting a healthy prenatal diet may ultimately lower ADHD symptoms and conduct problems in children."