Is it acceptable to bring your own food and drink when visiting someone?

I am an extremely frugal person. We recently lost our son and our friends are trying to come over occasionally to give us company as we grieve.<br><br>They always bring me coffee and snacks. The coffee is expensive and the snacks are as well. I would rather buy my own groceries. It's not because I don't trust them to buy me new coffee beans, it's just because I know what I like to eat and what is in the processed snacks they buy.<br><br>I've told them that it's not necessary but the next time they come over, it's with snacks again. I want to bring my own food and drink with me because I don't want to hurt their feelings. I've politely said "no, you don't have to do that." But the next time they bring food again! Is it rude to bring my own food and drinks with me? Or should I just suck it up and eat what they give me? Should I just be more blunt and tell them I want to bring my own food?