My good friend Linda has some of this going on at her house. It is a common occurrence in children who suffered from neglect in their early years. I believe there are several reasons why. Here is what I've been told. First: If the child was in an orphanage or on the streets for the first few years this may have been the norm for survival. While you may be providing them with plenty of food now this old fear of not having enough runs deep. Second: If they suffered neglect they were sometimes not fed. They still have this same fear of not getting what they need. Third: There is something wrong. Their is a whole in their heart and they are filling it with food because they don't know what is wrong. (How many of us are guilty of emotional eating? I'm raising my hand) Fourth: Food is the on consistent thing in their lives of constant moving, betrayal and abandonment. It takes on the emotional quality of a friend who comforts them.
There are several ways to deal with this. I have one friend who says his kids can "Eat what you want as it is not right before a meal." This takes all emotion from the food as far as emotion given by mom about it. I have heard of people preparing a goody bag of acceptable foods and having them keep it in their room. It should be made clear that you understand they need this while they are developing their trust in you. They need to know that others in the house who have developed the trust don't have these goody bags and they won't need them for ever either. They are to let you know when they don't need it any more. Alarms on the bedroom door prevent midnight refrigerator raids. We do this or entire boxes of food disappear. Snuggle time each day when you feed them caramels or vanilla ice cream from your hand to their mouth can help satisfy this need for sugar.
I don't know if any of this helps. This is a tough area if you let your emotions enter the picture. It has to be seen as a symptom of an illness. It is a part of RAD. We need to work on building empathy, trust, gentle physical touch. Just treating the symptoms is like treating the symptom of a physical illness. The symptom will not fully subside until the illness is gone.
If your child has been healing from RAD as Linda's child and Taz have, this can be a clear warning sign that they are regressing and need some TLC. If they had the flu would we be angry? No we would give them TLC. Same needs to happen here. Easier said then done, I know. Be the grown up here. Be strong. Together we can help our children heal.