I forget which thread this was in so I am just starting a new one.

Someone was discussing the sinfulness (or lack thereof) regarding smoking, not sleeping enough, drinking, etc.

What does the Church teach about this?

Very interesting. Bumping this because I'd like to know the answer too! I don't smoke or drink but I'm guilty of not getting enough sleep! I blame college.

I don't think there is a magic number to any of these. I think sin of commission begins when one is aware that he needs to smoke less, sleep more, or drink less because of a condition he is aware of. Without good reason, ignoring the warning signs of ill health in these cases (or the awareness of the development of a bad habit or addiction) would probably be sin. A sin of omission probably exists when one just generally smokes more, sleeps less, or drinks more than what is considered healthy and one doesn't "check in" with himself (or his doctor) to make sure that he is taking care of himself.

So, I would say in general that each person is different and that as long as one has a conscience that is formed to "look out" for warning signs (fatigue, breathing problems, liver issues, crankiness, addiction), along with a resolution to change behavior that appears to be harmful, then engaging in these activities is probably ok and not a violation of your body being a temple.

FJ

Certainly drinking within the mean of sobriety is even a virtue! (We all the know that exceeding the mean is drunkeness and that is bad, but one can also err by deficiency. While except in peculiar cases not-drinking is not a sin, still there is a greater virtue in using it rightly, and this virtue is that of sobriety). St. John Chrysostom goes as far as calling it blasphemy to say that drink is itself evil!

As far as things like sleeping (or not eating enough, or whatever the case may be with general rest and food) common sense is a great guide. To needlessly fatigue oneself to the point of ill health would be wrong, as fj has said. But a doctor in a disaster area that works himself to exhaustion saving lives? One should exercise reasonable care of health, and what is reasonable varies between persons and in different circumstances. We do not worship the goods of the body over those of the soul, but neither do we neglect them to the point of damage, save necessity (one risks life and limb for certain higher goods, and we recognize this). One must also bear in mind there state of life. To needlessly neglect sleep (because partying, or because you procrastinated on something, etc) to the point that it impacts your ability to perform the duties of your state of life would be wrong even aside from any damage to one's health from doing it habitually. It is a matter of priorities.

In other words, there are things to be valued about the preservation of the body. Aka, the comfort of others, the moral support of others, etc. I can see this for losing sleep, but what is the inherent virtue in drinking moderately?

Drinking moderately is not bad for the body! Indeed, it is good (speaking generally). We are admonished by scripture against drunkeness, but also told to give strong drink to those mourning to ease their mourning. Drink, used rightly, aids with coniviality. Hence, following Christ's example at Cana, one can drink more than normal at a wedding (but not to drunkeness). "Wine drunken with moderation is the joy of the soul and the heart." and "Wine taken with sobriety is equal life to men; if thou drink it moderately, thou shalt be sober." and ""Sober drinking is health to soul and body; wine drunken with excess raiseth quarrels, and wrath and many ruins." All from Ecclesiaticus!

Sobriety is that habit by which one uses drink with due moderation. That is what a virtue is. The habituation of an appetite to right reason and consisting in a mean between two extremes. To be unable to drink soberly is incontinence. A man may abstain completely because he is incontinent, and that is fine, but he lacks the virtue of sobriety. It is because he lacks the virtue that he abstains altogether. The man constantly getting drunk lacks virtue. The man who is able to drink and due so within the limits of sobriety, as a manner of second nature (that is he doesn't have to fight the urge to drink more, etc) has a virtue. That is what virtue is.

I smoke cigars. What's a temple without insence?