I happened across an interesting article on the Forbes website
(of all places) about all the ways that the fast food giants manipulate and adulterate the humble egg. It brought the ridiculousness of mass market overprocessed food home to me in a way that a simple list of ingredients never has before.
This might be because I have pet chickens.
Every day I collect between 1 and 3 eggs from my feathery gal pals. About 75 percent of their diet consists of the (organic, vegetable protein-only, chock full of vitamins and minerals) chicken feed that I set out for them. During the day, they scratch around in their coop for the grain I toss them, eat my leftovers, or (when I have time to supervise) poke around the yard for whatever delicious morsels they can scare up. Their eggs reflect this ideal chicken lifestyle (technically called "Pasture Raised").
Their shells are substantially thicker than those of grocery store eggs - if I drop one, as I often do, it's only about 50/50 odds that the egg will crack. The shells of battery hen eggs are thinner because the hens are forced into laying more eggs faster than is natural, and their bodies don't have time to lay down as thick a layer of calcium.
The yolks and whites are firm, not runny. Egg contents lose their structural integrity with time. I usually eat my eggs within 5-7 days from the time they were laid. Grocery store eggs may be as much as 90 days old, or even older.