what can they eat that isn't going to kill them?!
Answers:
my mom has celiac disease (allergic to gluten). she doesn't eat any processed foods because those contain msg most often, she eats meats, salads, a lot of yogurt and breakfast smoothies, you can eat most chocolate, and other stuff, just depends how processed it is to contain MSG. and there are special flours that can be substituted for wheat flour so baked goods aren't totally out of the menu. Try Whole Foods (they also carry GF frozen dinners) to for processed foods without MSG and Gluten Free. Also things like wheat noodles can be substituted for rice noodles. the is a brand called UDIES that is rice bread which tastes very good.
personal issues
Meat, vegetables, fruits, nuts, legumes
BBQ chicken, t-bone steak, pork chops, fish sticks.....
Fruit.