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.

If you’re familiar with Jonathan Haidt’s book The Righteous Mind or the moral foundations theory, it’s no surprise that our morality is easily intertwined with our basic biological urges for food. It’s also no surprise that strong emotions like disgust can mingle with our food choices, causing extreme reactions – people aren’t just failing to achieve optimal results by consuming the “wrong” macronutrients in their diet, they’re degrading their bodies through their impure and improper behavior.

But, how do our bodies actually regulate our weight? How do we regulate our levels of body fatness?

Everyone knows that one guy who is freakishly lean – seemingly no matter what he does for diet or exercise.

Everyone also probably has a cousin who lost a ton of weight on a low carb diet. And then there’s the friend who had great success with paleo. And the other who went vegan and swears it changed his life.

What about hunter gatherer cultures? Kitavans (eating a diet of approximately 70% carbohydrates – predominantly from sweet potatoes) to the Inuit (eating a diet of approximately 50% fat) all seemingly regulate their bodyweight at healthy levels and are free from chronic diseases that plague industrialized cultures.

Is there a thread that ties all of these things together? How can so many seemingly disparate approaches to eating all produce results in both individuals and populations?

There is a “middle way,” so to speak, and Stephan Guyenet has been promoting a framework that makes thinking about bodyweight, body fatness, and appetite all a lot more reasonable.

Stephan has a PhD in neurobiology, and has published research on the role of the brain in regulating body fatness – particularly the role of hypothalamic injury and inflammation.

Stephan has blogged actively for years – first at Whole Health Source, and now at his eponymous site www.stephanguyenet.com. He’s also been a presenter at conferences such as the Ancestral Health Symposium.

Fortunately for the unwashed, unclean masses who have been defiling themselves and their palate through improper eating behavior, Stephan has just released a book called The Hungry Brain that distills the comp