From personal experience, when you're hungry, you just wanna eat, all other considerations go out the door. Is it good for me, is it actually food, is it gonna make me fat and sick? Don't care, I'm hungry, I wanna eat. The more hungry we are, the lower our standards get.
Also from personal experience, food quality varies according to immediacy. For example, where a hot meal is served, it tends to include more perishables like fresh meat and bread. Where a food bag is given, it tends to include more preserves like canned meat and biscuits. Fresh food has a shorter shelf life than preserves. It's just logistics.
Meat is always more nutritious than any other food, regardless of whether it's fresh or not. So, for somebody who gives food, if he wants to give the most nutritious preserves, he should prefer canned meat rather than biscuits. It may sound like I'm pushing my own personal preference here but it's just a matter of fact of nutrition, not preference. Also, since it's very obvious that the bulk of food given is mostly carbs, giving canned meat (or fresh meat for soup kitchens) just makes sense for somebody who wants to do the most good.
An anecdote. A while ago, we had an after-game dinner at the golf club. It was prepared by a caterer, it came in large aluminium platters. Pasta and meat and a few other things. The meat platter (there was only one, duh) went in the first few minutes, there was still two platters of pasta left at the end. When food is free and when there's a choice, people will choose the best first. Pasta, everybody can make it at home, who the hell wants to eat that when there's meat at a free dinner after a game?