Chief among these signals is the hormone leptin, but many others play a role (insulin, ghrelin, glucagon, CCK, GLP-1, glucose, amino acids, etc.) The Hungry Brain is part of Guyenet’s attempt to explain this third model, and it basically succeeds.
But to be more scientific about it, the specific things involved are some combination of sweet/salty/umami tastes, certain ratios of fat and sugar, and reinforced preferences for certain flavors.Modern food isn’t just unusually rewarding, it’s also unusually bad at making us full.Guyenet discusses many different reasons this might have happened, including stress-related overeating, poor sleep, and quick prepackaged food.But the ideas he keeps coming back to again and again are food reward and satiety.Various groups tried to design various new forms of rat chow with extra fat, extra sugar, et cetera, with only moderate success – sometimes they could get the rats to eat a little too much and gradually become sort of obese, but it was a hard process.
Then, almost by accident, someone tried feeding the rats human snack food, and they ballooned up to be as fat as, well, humans.
Overeating is caused by a kind of “internal starvation”.
There are other versions of the insulin model, but this is the one advocated by Ludwig (and Taubes), so it will be my focus.
The Hungry Brain gives off a bit of a Malcolm Gladwell vibe, with its cutesy name and pop-neuroscience style. He is very serious about what he does and his book is exactly as good as I would have hoped.
He’s a neuroscientist studying nutrition, with a side job as a nutrition consultant, who spends his spare time blogging about nutrition, tweeting about nutrition, and speaking at nutrition-related conferences.
Not only does it provide the best introduction to nutrition I’ve ever seen, but it incidentally explains other neuroscience topics better than the books directly about them do.