Parents need to take charge of their child's diet. They need to make sure they are eating healthy, balanced meals. Most children will receive the proper nutrition to grow strong and healthy through good eating habits.
See also:
Myth: Sugar and Food Additives Cause ADHD

What Causes ADHD: Myths vs. Facts
10 Medical Conditions That Share Symptoms With ADD/ADHD
Common Symptoms of ADD & ADHD in Women
7 Behavior Modification Strategies for ADHD