1 Cor. 6:18-20
18 Flee fornication. Every sin that a man doeth is without the
body; but he that committeth fornication sinneth against his own body.
19 What? know ye not that your body is the temple of the Holy
Ghost which is in you, which ye have of God, and ye are not your own?
20 For ye are bought with a price: therefore glorify God in your
body, and in your spirit, which are God's.
If your body is the Temple of God, then I'd say that neglecting it would be a sin.
The remainder of this answer is based on a sermon I heard recently at my Church, which taught the differences between a Biblical Absolute (the Bible explicitly commands or forbids it), a Conviction, based on overwhelming scriptural references, and a Personal Preference, based on how you view God.
As to your specific examples:
Points 1, 2, 4 and 5:
The Bible doesn't say, explicitly, or even implicitly, other than the verses I quoted above. This puts this "healthy eating" in the category of a personal preference or a personal conviction.
You could make an argument for it based on the verses I quoted, but in my personal opinion, it would be one that I would live by myself, not one I would try to preach to others. And I would certainly not look down on other Christians that didn't think the same way. That would be pride, and God's word is clear on how He feels about a proud heart and a boastful spirit.
As for point 3. The Bible has enough to say about drunkenness that this would be a conviction based on overwhelming scriptural evidence. The Bible never says drinking is a sin, but there are plenty of verses saying to not be drunk, drunkenness is foolishness, etc.
However, as a whole, I believe that God is much more concerned with our heart and mind than He is in our body. His Word has a lot to say about our keeping our minds, our heart, and our spirit clean, and about what our attitudes toward Him and to others should be. It contains only a few verses referring to care of our bodies.