Whether or not you like the ethics, we have evolved to preferentially eat animals, and especially fat animals. I've discovered that from a nutritional perspective eating meat is like buying houses - buy the worst house on the best street; eat the worst meat of the best animal. Fillet steak is beautifully tender and is great for building muscle. If you want also to build your bones, joints, organs and brain, then eat the whole animal. Sardines and shellfish are great in part because you eat the whole animal (not that shellfish have much in the way of bones or brains). Our distant ancestor were scavengers, thriving on brains and marrow. Later they became active hunters, but hunters (like lions) prefer the organs and innards to muscle (see Stefansson).
Being aware that cured meats are suspicious, I thought about making my own. So I looked at Jeremy Schmid's recent Bangers to bacon. Every recipe called for Colorquick. The glossary describes it thus: "Colorquik is the standard preserving agent used in dried, smoked and cured meats. It prevents botulism, enhances flavour, and helps retain the natural pink colour of meat. Colorquick must not be used as common salt! It is a highly poisonous substance. It must be measured with accurately and used with extreme caution [author's italics]. Always store Colorquick out of reach of children.'' And we are supposed to eat that?
1 In New Zealand, the Harmony brand and all organic pig farms are true free range, Freedom farms are 50% free range. The SPCA blue tick indicates 50%+ free range. The pork industry's Pigcare label is irrelevant - it just means complies with NZ law. (TV3) ⇑