Look I get frustrated when my kids don't eat, esp when we go to an expensive restaurant. My wife and I don't beat, nor do we yell at them. As long as they are not refusing because they don't like the food, esp if they are trying something new. We tell them they aren't getting any desert (if there is any) and nothing else to eat later. Many times they don't ask for anything, but many times we get home and they beg for chips, ramen etc. We put up a short fight not allowing them to have anything, but eventually we allow them to have only vegetables or fruits to tide them over.