I usually bring many power bars, string cheese, and bags of fruit and nuts in my purse to help with the hungries. The single serving size can of tuna is a good idea too. I know people who do the same thing for lunch while skiing to avoid paying the high food costs at the ski areas. The tuna fits in a jacket pocket and doesn’t weigh much.
She mentions getting good prices on food items at a chain drug store. Her strategy of ordering just a green salad is fine if supplemented with a protein source, like the tuna or string cheese. Otherwise, she will feel very weak from no protein later.