Maybe try looking into sugar addiction, it sounds like you haven't tried that yet. Some people's bodies treat sugar like an opioid drug. By sugar I mean sugar, fructose, honey, all white, refined flours, bread, pizza crust, crackers etc. These people tend to crave sweets and processed foods more than other people. When they are coming off their sugar high they have all the behaviors you described and it happens over and over everyday. My 7 year old son has this problem and the behavior problems are similar. Do not take all those foods I just mentioned away (like you said he'd just starve). The healing process has to be done in baby steps over a period of many months and getting off sugar is one of the last steps after much healing has occurred and the child is accepting of the process. The first step is serving breakfast with protein as soon as he wakes up every day. If he is 60 pounds go for about 16 g of protein, if he is 45 pounds go for about 11g. You could do egg sandwiches with whole wheat bread and cheese, or maybe get some whey protein and do smoothies. Avoid cereal.
Potatoes not Prozac by Kathleen DesMaisons for parents
Little Sugar Addicts by Kathleen DesMaisons. for kids