If it is clearly wrong from a biblical standpoint to work in the tobacco industry is it also wrong to work at a McDonalds or sell Twinkies?
If I Corinthians 6:19 is prohibiting substances that are harmful to the body (besides sexual sin), then you can just as well preach against McDonalds and Twinkies as well. But I’ll bet you don’t preach against those other things, brother. Just challenging you a little.
I believe you are referring to the answer to the question "Can the church sponsor the growing of tobacco to raise funds?"
Your point is inconsistent. Tobacco has no nutritional value for the human body, but it does contain many known poisons. Fast food, such as McDonald's, does have nutritional value, though eating any food to excess or to the exclusion of all other foods is not sound. Despite the current climate to frown on any successful business, eating a hamburger at McDonald's once in a while will not cause any harm. "For every creature of God is good, and nothing is to be refused if it is received with thanksgiving; for it is sanctified by the word of God and prayer" (I Timothy 4:4-5).
Even sweets, such as Twinkies, which have calories but not much else are not harmful so long as it is not done to excess. "My son, eat honey because it is good, and the honeycomb which is sweet to your taste" (Proverbs 24:13). But this is balanced by, "Have you found honey? Eat only as much as you need, lest you be filled with it and vomit" (Proverbs 25:16) and "It is not good to eat much honey" (Proverbs 25:27).
Thus you have not made your point. Tobacco causes harm to the body and gives no health benefits. The foods served at McDonald's and sold by Hostess have benefits when eaten in reasonable amounts.