The Hungry Brain: Outsmarting the Instincts that Make Us Overeat
By Stephan J. Guyenet
Why is it so hard to turn down tasty foods? Why, once we lose weight, is it so hard to stay at a lower weight? What changes in the American diet made a lean, healthy nation so rapidly change into an obese, unhealthy one?
For those who enjoyed Denise Minger’s Death by Food Pyramid, Stephan Guyenet’s The Hungry Brain is an enjoyable follow-up. Whereas Minger focused on changes to food and agriculture and shenanigans at the U.S. Department of Agriculture (USDA) and other places, Guyenet focuses on the science describing the impact of these changes on our brain’s various food-reward and fat-regulation systems. The Hungry Brain then traces the influence of these changes on our ever-expanding societal waistlines and the explosion in degenerative diseases. Chapters three through five of this book were some of my favorites, exploring the complex connections between food reward, palatability, industrial food, obesity and ill health.
The three chapters are full of exceptionally interesting information, such as charts on car ownership (correlated with less physical activity), food spending allocation over time and sugar and fat consumption. One of the most troubling topics addresses the top calorie sources for US adults and children, namely processed grains, corn- and soy-fed chicken and sugar-based pseudo-foods.
These chapters highlight a few things that Wise Traditions readers are already familiar with, such as the rising consumption of vegetable oils and refined sweeteners (especially high fructose corn syrup) and their impact on our eating habits and health. Guyenet also adds useful information and offers a perspective on how these changes to our diet affect our brains and eating habits in ways that most people are unaware of. Guyenet describes the transition to vegetable oils as follows: “Added fat intake has doubled. The type of fats we use in our cooking have also changed profoundly—animal fats, such as butter and lard, have largely been supplanted by refined seed oils (vegetable oils) such as soybean oil. Rather than getting our fat from whole foods like meat, dairy and nuts, we now get it primarily from oils that are mechanically and chemically extracted from seeds. These liquid oils are cheap and convenient to add to foods that would otherwise contain little fat, creating such food reward masterpieces as French fries and Doritos.”
Guyenet similarly discusses sugar and its use in creating hyperpalatable, high-reward industrial pseudo-foods that wreak havoc on our brains. In fact, this is what sets The Hungry Brain apart. Whereas most comparable books focus on the impact of processed, industrial foods on our bodies, Guyenet is able to show how these foods derail the complex and subconscious brain systems that oversee how we relate to food.
Throughout the book, Guyenet discusses a number of traditional groups such as the Hadza, with sometimes surprising observations. For instance, many hunter-gatherer-type people are amazingly healthy in spite of diets that are almost completely devoid of low-calorie green-matter-type foods (sorry, Whole Foods and your “nutrient-dense” food grading system!). These groups also can engage in feats of feasting that modern people can barely fathom. For example, Ache men can eat “five pounds of fatty meat each in a sitting,” drink “one and a half liters of pure honey,” or eat “thirty wild oranges similar to the fruit we buy in the grocery store.” The Hadza drink honey “like a glass of milk.” Despite the fact that these groups “guzzle fat and sugar when available, neither the Hadza nor the Ache have obesity.”
If chapters three through five focus on the changes to the food system that make our finely tuned brain systems around food go haywire, the remainder of the book explores these problems in greater depth and detail. These chapters talk about why our brain drives us to eat even when eating no longer helps us but hurts us, covering topics such as leptin resistance, sleep, stress, the hypothalamus and the caloric value of food. These middle to later chapters of the book are an adventure through the complex systems that control expression and suppression of hunger.
One interesting thing to note is the discussion in chapter seven of the “hunger neuron” and the role of inflammation in this process. Given inflammation’s role in many chronic and degenerative diseases and its ties to processed foods, it is a reminder of just how costly cheap food can be to our health. It also reminds us how we find ourselves culturally trapped in a giant downward spiral. One can easily step onto the path toward the nutritional abyss through many roads, but it is much harder to turn back off once you have begun heading in the wrong direction.
The chapters on sleep and stress help tie together many areas of research, linking them directly to food intake and fat. Why do we crave certain types of food when we are sleep-deprived or stressed? Why is shift work so dangerous to our waistlines? (Answer: because the brain isn’t wired for it!)
The book ends with a short and helpful review chapter, taking half a dozen pages to wrap up and walk back through the big-picture ideas laid out in the earlier chapters. It then moves to action. One’s view of Guyenet’s recommendations will be driven by one’s political persuasions, but I think all of us will agree with this suggestion: “Simply change the way the government subsidies are allocated to commodity crops, such as corn, soybeans and wheat. These three food crops receive more subsidies than any others in the United States—totaling over ten billion dollars per year. They also happen to be the basis for many of our most fattening food ingredients…. Essentially, taxpayers are subsidizing the very foods that make them sick and fat.”
The personal recommendations are simple, a reminder that at the end of the day, avoiding foods that are bad for us isn’t all that hard—except it is. It isn’t rocket science or advanced brain biology, but something both easier and harder. It is about choices to create an environment that allows us to minimize our exposure to processed foods and maximize our opportunity to consume real, whole foods.
For those who want hard science on this subject, Guyenet delivers without being overly technical. He discusses a wide variety of technical terms and studies, but at no point will a reader feel confused or lost, even as he explains and explores complex aspects of human brain function, food reward and the studies that shine light on how these work in the modern world.
I will end my review with a line from deep in the book (page 156), one that will not surprise WAPF followers but shows Dr. Price’s wisdom being proved over time. Quoting a scientist who says that “the scariest implication…is that the food we eat may cause damage in areas of the brain that we need to regulate weight loss and appetite, as well as our blood sugar, and to some degree, our reproductive health,” Guyenet adds, “To put this simply, modern industrial foods damage our brains, which in turn damage our bodies and make us even more prone to consume industrial foods. Best to never start this vicious cycle in the first place if you can.”
The Hungry Brain was an enjoyable, educational and excellent read from someone I have followed for many years. It will provide readers with a better understanding of how the human brain (and thus body) functions even in an age of hyperpalatable foods that may lead us to endless ill health. Two thumbs up.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly magazine of the Weston A. Price Foundation, Summer 2017.