I've seen this movie between 2006 and 2007 on cable TV.
I am not sure but the protagonist could be
Robin Williams .
In the movie, a group of people are struggling to survive famine. And they come up with the idea of choosing one victim (by random selecting device, not sure) so that the rest of them would have more food left.
This person is then killed.
I can remember one scene in which the girlfriend of the man to be killed, is collecting pieces of food to offer to him since he will shortly die.
One of the quotes they used in the trailer of this movie is :
What will I eat tomorrow?
Again, that quote could have been said by Robin Williams.
EDIT: It is worth mentioning that when anyone is killed, he/she is killed in order for him/her not to consume any more food. No cannibalism involved throughout the movie. On a different topic: You would see people hiding food before opening the door to anyone who knocks.
I always thought: why won't they just let the guy go, and maybe starve to death on his own? Why the extra burden of having to kill him. He/she might survive alone, you just don't give any food to them.. That bugged me the whole time I watched the movie, but there might be a reason that I may have missed.