In a worst-case scenario, if one had to eat parts of oneself, which non-organs would be the most nutritious? Nails, hair or earwax?
Firstly, nails and earwax are virtually indigestible (unless you pressure cook them for a long time in mild acid). Hair would be useful if we could extract the keratin from it, but we humans can't. So, all three suggestions are pretty much useless. One possible suggestion from a writer to the new scientist was to eat your own faeces, because of the 'good protein' from the vast number of dead gut bacteria. And who knows, depending on what you've recently eaten, you might even get one of your five a day!