I like this argument comparing consumption of meat to tobacco. Here is a little of what Kathy Freston says in her article:
"When I think about the effect of animal products on human health, I'm reminded of how quickly we've done a national about face on tobacco, and I look forward to the day when the Times magazine has a similar apology from someone who promoted animal products -- because the evidence is in and it continues to grow: Animal products kill a lot more Americans than tobacco does.
The West's three biggest killers -- heart disease, cancer, and stroke -- are linked to excessive animal product consumption, and vegetarians have much lower risks of all three. Vegetarians also have a fraction of the obesity and diabetes rates of the general population -- of course, both diseases are at epidemic levels and are only getting worse."
Freston makes a strong case. Here is the rest of the article: http://www.huffingtonpost.com/kathy-freston/animal-products-cancer_b_1316222.html