It's common wisdom that you don't want to know how sausage is made. Well, for good reasons, actually.
Back in 2008, then high schooler Brigid Prayson teamed up with her doctor dad to do histological and electron microscopy studies on various brands of hot dogs to see what's exactly in them:
Meat content determined by microscopic cross-section analysis ranged from 2.9% to 21.2% (median, 5.7%). The cost per hotdog ($0.12-$0.42) roughly correlated with meat content. A variety of tissues were observed besides skeletal muscle including bone (n = 8), collagen (n = 8), blood vessels (n = 8), plant material (n = 8), peripheral nerve (n = 7), adipose (n = 5), cartilage (n = 4), and skin (n = 1). Glial fibrillary acidic protein immunostaining was not observed in any of the hotdogs. Lipid content on oil red O staining was graded as moderate in 3 hotdogs and marked in 5 hotdogs. Electron microscopy showed recognizable skeletal muscle with evidence of degenerative changes. In conclusion, hotdog ingredient labels are misleading; most brands are more than 50% water by weight. The amount of meat (skeletal muscle) in most brands comprised less than 10% of the cross-sectional surface area. More expensive brands generally had more meat. All hotdogs contained other tissue types (bone and cartilage) not related to skeletal muscle; brain tissue was not present.
Science, must you be such a buzz kill? Link
* Never ask what's in your food. Your body is well buffered to tolerate most any insult, as long as it's not prolonged for decades.
* Never watch your food being prepared. You won't eat it.
* Never complain about how your food was prepared. You'll end up eating a lot of spit. (Or, if you're in Japan, a lot of dandruff in your rice.)
http://howfoodworks.blogspot.com/2009/02/pepperoni-is-raw-meat.html
You're welcome. XD
(Of course, pepperoni ends up being cooked fairly well once it's on a pizza, for example, but if you just slice pepperoni and stick it on a sandwich, technically you're eating cured and dried raw meat.)
To this day I do not know if the teacher knew that the cafeteria would be serving hot dogs that day, or if it was just a lovely coincidence. I do remember that I was the only person at my table who ate a hot dog. I got great entertainment out of watching the faces of my peers at the table slowly turn white and assorted shades of green.