by Doctor Science
A few months ago, I read Catching Fire: How Cooking Made Us Human, by Richard Wrangham. Wrangham marshals many lines of very good evidence to argue that humans are physically adapted to cooked food. One unexplored prediction of his theory is that, when proto-humans starting eating cooked food, they must have experienced a true "obesity epidemic".
I'm cutting this because discussions of weight, etc., are so fraught.
The high points of Wrangham's evidence compare humans to the other chimpanzees:
- shorter gut, and digestive system is a smaller proportion of the body
- smaller teeth and mouth
- much less time chewing food -- chimps chew 4 hours a day, humans about one hour or so
- there is very little evidence for any humans, even castaways, surviving for an extended period without cooked food
- there is *no* evidence that children can grow eating only raw food
These eggs are neither raw nor cooked (sorry, Claude), but they are pretty, also seasonal. I'm trying to find the photos I took of our pysanky seder-plate egg, with the image of the burning bush -- alas, the mice ate it. Next year, on our seder plate…
So, once our ancestors started cooking food, they could get more calories and nutrition out of a given item. If they started with a chimpanzee-like gut, mouth, and chewing habits, they would have taken in *many* more calories than their bodies were evolved to handle. Cooking is culture, it's something we learn, so it's pretty much a given that the change in diet from starting to cook would run much faster than the evolution of a shorter gut, etc.
In other words, we would have become obese -- and only gradually, over an evolutionary timespan, did we adapt and become dependent on our new, cooked diet.
I've been wondering if the so-called "obesity epidemic" reflects (in part) something similar: if our food has become, in some fundamental but unnoticed way, more digestible. This might be a clue to why increases in BMI and obesity have been going on for a century.