Poor nutrition can equal a major mental imbalance. An old study found that around 70% of mental patients were actual nutrient-deficient and could be treated or possibly cured with proper nutrition.
(I ate mental institution food for close to a year and I had encountered some serious physical issues that made me shut the doors on college and flee - BTW, it was a government-run school that paid for me to take my GED, gave me Dental Assisting training and then put me through college via a government grant, so we ate in the same cafeteria as the neighboring 'nut-house'.
Why do you think depression is so rampant nowadays? I think sweets are definitely the devil, but the real elephant in the room here, is nutrition overall!