Shit, it really seems like Kizaru brought food to Luffy. But he probably did it secretly because he didn't want to officially betray the Marines. He wants Luffy to recover so that Luffy can do the job while he acts busy himself. I don't like that at all, because there have been no signs of it so far. The happy togetherness in the flashback isn't enough for me, because it had nothing to do with what was happening on Egghead in the present. So why the sudden change of heart? Assuming it really was Kizaru, of course.