That tracks with what I found when I worked as a supervisor and nutritional consultant with a drug and alchohol program for young men. I changed the diet at one of the facilities from mostly sugar, cheap beef, pork and junk food to one that included lots of raw vegetables and fruits, along with juices, including green leafy vegetables and other sources of missing vitamins and minerals, plenty of omeaga-3's and substituted turkey and fish for much of the meat along with encouraging more physical activity for the computer and couch potatoes. The difference in behavior was noticeable - with less anti-social behavior, less drug and alchohol cravings, fewer relapses and improved self-esteem.
Here is an interesting page on Chris Gupta's site:
A big point of concern is that nutritional deficiencies when children are developing their bodies in virtually every are can in many instances result in abnormalities in their systems and organs that can never be fully repaired. No system is more vital than the central nervous system and no organ more vital than the brain - especially when it comes to mental performance and social interaction.