If you don't have the common "dog" to either arrange a packed meal or eat before departure or on arrival !, then you should not be in this job !. If you happen to work for a full service outfit "where the sandwiches & coffee flow like wine" ,then lucky you !.I have heard much whinging over the years about "blood sugar " et al. The main problem is people are loathe to put a hand in their pocket !.
The majority of my colleagues ( on the whole & i include myself !), range from a little to grossly overweight.