Pemmican is easily transportable. Bags of pork rinds are nice. Macadamia nuts keep well at room temperature. Getting a steak from the dining cart may be a little pricy. If there is anything buffet-like you will have to watch it. It takes a while before dietary self-controll is internalized in kids. (However, if you start young enough, there is a natural "disgust" mechanism in humans that keeps people from eating foods that are not consumed in youth - thus we don't eat bugs even though they are good for us).