Hello: The first thing I suggest is looking for diagnosis confirmation. Night terrors must be differentiated from epilepsy, this can be done with an electroencephalogram or polysomnography. The latter is done in a Sleep Medicine Laboratory and monitors breathing, heartbeat, muscle tone and brain waves; so it will show us the sleep phase when the event is occurring, and also will show if your son is having epileptic activity. If that is so, he will need another approach, and might need antiepileptic medications as carbamazepine or valproic acid. If the study confirms Night Terrors, you can adjust the clonazepam dosage, or use anti depressive drug as Paroxetin, imipramine or amitryptiline trying to control them. i do not think the diet is a contributing factor, nonetheless is better for him to eat healthy and avoid big meals beafore going to sleep. Apply sleep hygiene measures: do not let him watch TV, use tablet or cellphone before going to sleep; do not let him drink cola or caffeinated drinks, let him exercise (up to 2 h before going to sleep). I suggest consulting with a Sleep Medicine Neurologist for a complete assessment. I hope this helps. If there is something else I can help you with, or if you have any doubt, please let me know.