@Jrainbow,
Are you being nitpicky? Yeah, probably a little bit. There are about a thousand other things more important in a marriage than one party bringing unwanted snacks into the house.
Is he disrespecting you? Not sure I would call it disrespect. But he certainly is not being supportive of your desire to keep the snacks away so you don't eat unhealthily.
Bottom line, you need to decide how much of a problem this is for you. If he is not going to stop doing this, then you can either keep nagging him about it which may lead to bigger arguments, or you can drop it and put the snacks somewhere that you won't regularly see them and be tempted.
Good luck.