Food charities, yes!
I DO think it's worth understanding the structure of food/hunger charities, at least in the US. In many places, there's a central food bank and then lots of smaller food pantries. Typically, food banks get the big bucks, have the big events, and give/sell food to pantries, etc. The pantries are run by houses of faith, service organizations, etc. and are open a few hours a week.
I was surprised to learn that a number of people in my area rabidly oppose the regional food bank, saying that pantries must buy their food from them, arguing that the food should be given. Having worked with a food bank in DC, I understand that food banks have the power of the purse to buy food at a discount no pantry could dream of getting. And because food banks have a distribution network, they can also handle large donations of soon-to-expire food, etc.
I've tried to explain to food bank opponents that it's a better deal for the pantry to buy food from the food bank; the pantry will receive more for their money. But there's no convincing them. Which is fine.
Anyway, the point is to understand the system and make an informed decision about where you want to donate.