Be creative, if your child loves those juice boxes pour them out when the child is asleep, refill with diluted juice and put a piece of scotch tape over the top. You'll get away with it. Lunch is a good time for leftovers, we are trying to push extra protein into them. No supplement can do as well as the real thing. A sandwich is really okay as long as some protein is in the middle.
Bread is really where the controversy begins.
Try to remember the body converts starch to sugar within 6-12 hours, so that is why we limit the consumption. We know your child may be stubborn at first and only eat the starch on the plate. ACT DUMB Don't fight them, if they do not want to eat the rest do not force them. When they want more food present what they have not finished. Believe it or not their pattern of eating will change.