There's been a culture war raging for decades - high carbohydrate diets vs high fat diets, paleo diets vs vegan diets, people tracking all of their food in apps while others shout that "calories don't matter," and a bunch of people off in the corner sipping exogenous ketones. Stephan Guyenet is a neuroscientist and researcher who wrote "The Hungry Brain" on how our brain regulates are appetitie.