not sure this is for everyone as some people are fussy with their sandwiches (my hubby!) but i make mine up if i no i'm going somewhere and eat them out. even when shopping, people eat gregs food on the go why cant i use my own? i no exactly whats in it.
Or if it is going to be dinner time when i'm out, i have half sandwich before i go out and the other half when i get back in. seems funny but works so far, if i didnt have something to eat i would binge. i did this when people where having a pub lunch, why should i not see my friends because there having food. seemed funny not eating with them but i told them before hand. i made a joke of it so didnt look fussy.