If the head tremors are stopped after giving a simple sugar, then he needs more complex sugars in his diet so that his blood glucose levels don't peak and drop. If he didn't have the tremors on his food when being fed "x" amount, then go ahead and feed him as you normally would do.

The brain works on 2 things..1.sugar (or glucose) and 2. oxygen. The brain cannot store either of these two items. They must be supplied continuosly and the way that those are delivered to the brain is through blood. Therefore, the blood must contain adequate amounts of glucose at all times to nourish the brain.