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).