Someone was ridiculed during dinner so I have to post this:
Romans 14:2 refers to meat and vegetable in the context.
14:5-6 especially verse 6 refers to which day to eat meat and to eat vegetable. E.g. Roman Catholics used to eat only vegetables on Fridays.
14:10 regardless of how one interprets about eating, one must not treat others with contempt. Someone is wrong here.
14:14 following the context, the unclean here refers to eating meat when one is to eat vegetable.
14:15 says if someone is distressed because of what you eat, you are not acting in love. That is, if someone believes it's not good to eat meat on a certain day and you, knowing that person's belief, still eat in front of that person, you are not acting in love. Again someone is wrong.
14:21 it's telling one to abstain from meat and/or wine when eating with the weaker ones. Please note here is not about whether pork or beef but about meat all together. Again and again that someone is wrong.
1 Corinthians 6:12 it's about sexual immorality which Paul used food as an analogy for sex if one reads the whole context from 6:12 to 6:20.