high on the hog: luxuriously
All the best parts of the hog—chops, for example—are located high up on the hog's body, so anyone who can afford to live high on the hog must be doing very well indeed financially. Most colonial Americans couldn't afford to live that high. They ate every part of the hog, from the snout to the tail, mostly in the form of salt pork. Pigs were popular as meat animals because they were relatively easy to raise. They practically fed themselves, just needing to be turned loose among the corn stalks so they could "hog down the field." Salt pork kept well and was a convenient food for travelers, so early Americans ate a lot of it. The ubiquity of pork is probably the main reason why Americans had the reputation among Europeans of being tremendous meat eaters.
Live high on the hog as a figurative expression did not begin to appear in print until the 1940s. The first known use appears in H. L. Mencken's 1941 autobiography, Newspaper Days: ". . . they . . . would be eating very high on the hog if they could only get their rights." Living high on the hog these days refers to any kind of prosperity, not just good eating.
Other pork-related terms are pork barrel spending and root hog or die.