Crash Course Nutrition: A Software Update For Our Outdated Hardware
Crash Course Nutrition: The Foundation
This article is meant to serve as an introduction to a series of Crash Course Nutrition Articles. The series is designed to empower the reader to take control of his or her eating behavior by learning about the related biology and why it exists.
In this introduction, we'll examine the mismatch between the way we were designed to eat and our current food environment. You'll see that our intake control problem is largely the product of a primitive feeding system operating in a modern world.
Then, you'll explore the unique characteristics of the human brain that make us uniquely capable of overcoming some of our primitive behaviors. As you read on, consider that we don’t have to change the physical structure of our feeding hardware to make our behavior more appropriate. Instead, we can implement a sort of psychological software patch by developing a deeper understanding of ourselves and where we come from.
Defining the Problem
If a group of aliens were to land in the United States tomorrow, they’d probably come to the conclusion that most humans are very bad at controlling how much we eat. However, if those same aliens touched down on earth even just a hundred years ago, they’d come to a very different conclusion.
Our relationship with food really started to change in the 1970s. The amount of the population that’s overweight or obese is higher than ever before by a huge margin. Widespread obesity is by no means the only problem. Type 2 Diabetes for example, is another one. To illustrate the recency of the issue, consider that Type 2 Diabetes used to be called “Adult Onset Diabetes” for the simple reason that, before the 1960s, there were zero documented cases of Type 2 Diabetes in children.
But even more malicious than these diseases are the psychological consequences of being unable to control our food intake. More than ever, people are unhappy with the way they look and feel. We embark on diets and exercise programs in effort to improve our physical and psychological well being, but we fail far more often than we succeed. If we don’t strive to understand why this problem exists, we’ll be stuck living in a world full of big people and even bigger problems.
The first step towards understanding the problem is to look for its causes. What's changed in the past century? Is it our biology? Are we somehow more prone to overeating than our ancestors? The short answer is, "No".
Our Feeding Hardware Hasn’t Changed
Our biology hasn't changed much since we were all living in caves. The process of evolution by natural selection is a slow one. It took millions of years for natural selection to hardwire our feeding behaviors into our physiology. In a literal sense, it's not the behaviors themselves that are encoded by our DNA. Instead, our genes encode for the neural circuits and hormonal feedback loops that give rise to our feeding behavior.
Programming any behavior requires the existence of an actual, physical, system to mediate a behavioral output. Behavior can only exist as a byproduct of the activity of underlying input systems. It doesn't just come out of nowhere, and it always happens for a reason. This is what it means to say that our behavior is “biologically based”. So in terms of feeding, certain neural circuits and hormonal feedback loops represent our feeding hardware that underlies our feeding behavior. This hardware has been around for tens of thousands of years and it's not changing anytime soon. Here's a cartoon of what our feeding hardware looks like:
The dramatic change in the way we eat can't be explained by the emergence of some new biological pathway. Something else must be to blame. Whatever that thing is, it must be working with our ancient feeding hardware to create the problem we have today.
Visualizing The Problem: A New Food Environment
Ask yourself again, what about the way we eat has changed in the past century? If it's not our biology, the deterioration of the developed world’s intake control must have its roots in a problematic relationship between our evolutionarily preserved feeding systems and the modern food environment. In other words, the advancement of civilization has created a food environment that makes survival an easier endeavor, but at the cost of confusing our biology.
To visualize the problem, imagine our biology as a square peg that used to fit very nicely in the square hole of our food environment. The fit was snug and secure until we, as civilizations, developed the power to radically change the world around us. So our food environment has dramatically changed, but our biology hasn’t. How are you visualizing it? A square peg and a round hole? Maybe the size of the hole changed. Or is it something else?
To create the appropriate visual, we have to account for how quickly and creatively civilization progresses. Likewise, the peg still has to fit into the hole to a certain extent. If the peg didn’t fit at all, the result would be a failure of our biology and the ultimate demise of our species. Taking those things into account, here’s how I visualize it:
Our biology has remained a square peg, but we’ve taken the square hole, filled it with concrete, and built a McDonald’s on top of it. The square peg still fits nicely through the doublewide doors of our imaginary McDonald’s, but once it gets inside, it never wants to leave.
In essence, our hardware is out of date in today's food environment. However, it would be wrong to say that our feeding hardware isn’t working. If anything, it’s working too well. The very neural circuits and hormonal feedback loops that once helped insure the survival of our species are now responsible for adding inches to our waistlines. The hardware is doing exactly what it was designed to do; it’s just doing too much of it.
A Second Visual
Here's another visual for you: The relationship between our feeding behavior and the modern food environment is like the relationship between a water balloon and a fire hose. The water balloon was designed to withstand the water pressure from something like a kitchen sink. However, try to fill that water balloon with the same water, but at pressures strong enough to knock a person off of their feet, and you’re left with nothing but a few pieces of tattered rubber floating in a massive puddle of water.
Our bodies are like the water balloon. They were designed to work best in an environment with a specific level of food availability. However, in the food environment of the 21st century, the flow rate of food is more like that of a fire hose than that of a kitchen sink. It turns out that we don’t pop like water balloons, we just keep getting bigger.
A Psychological Software Patch
Thankfully, even if we could, we don't have to rebuild our feeding hardware in order to gain control over our circumstances. Recall that every behavioral output is the result of integrating multiple inputs from different systems. One of these input systems is the prefrontal cortex and it's "executive control". For simplicity’s sake, this is the uniquely human part of our brain. In fMRI readings, tasks like rational thinking, future planning, and cognitive challenges show activation in the prefrontal cortex. Using this brain region, we can exert top down control over some of our more primitive behaviors. Humans can actively decide to endure temporary discomfort in the interest of accomplishing future goals because of the inputs from the prefrontal cortex.
The cortex wraps around the more primitive regions of the brain to serve as a "thinking" intermediary between basic processing and behavior. Just look at the images below:
Above, you can see the human brain divided into three parts. Each of these parts developed at a different point on the evolutionary time line. The more central regions evolved earliest, followed by the limbic regions in the middle, and then the cortex developed over top of it all. Below, the cortex size of various animal species is compared to that of a human. The shaded regions are the prefrontal cortex. (Images are not my own).
It was the ideas encoded by chemical and electrical signals in the prefrontal cortices of our ancestors that served as the spark to the fire of human progress. These ideas, passed down through hundreds of generations, represent our cognitive conquests over our more base behaviors. All of these cognitive conquests contain within them an element of foresight. The foresight necessary to avoid certain instinctual behaviors in the interest of improving our future circumstances. When societies come together around these ideas, the results are amazing. For example, the collective cognitive conquest over our instinctually aggressive and territorial behaviors led to a massive reduction in the amount of violence, murder, and theft that occurs in human communities.
The take home message here is that we have a unique ability to change the way we react to the more primitive parts of our biology. Don’t get me wrong, our behavior is still just as biologically based as it ever was. However, we have the power to change the way we interact with our biology. That is, by changing the strengths of the inputs, we can change our behavioral outputs. With this understanding of how our brain works, we can start to create a psychological software patch for our outdated hardware.
Downloading the Software: The Crash Course Nutrition Series
Strengthening the top down control of our feeding behavior requires that we become very familiar with the inner workings of our biology. The strength of our control is directly proportional to our ability to detect and intercept our primitive impulses to eat in excess of what we need. Knowing what to be on the look out for and when to be on high alert will empower you to take control of the way you eat.
The best way to uncover these principles is to rewind the clock of our evolutionary history to reveal how the hammer of natural selection shaped our feeding hardware and subsequent behavior. By putting ourselves in our ancestors’ shoes, we can start to make plain sense of our complicated feeding behaviors. Then, empowered by an understanding of why we feel the way we do about food, we can dive deeper into the biology to learn how to optimize our behavior in the pursuit of our health and fitness goals.
Think of reading this series of Crash Course Nutrition articles as downloading a software update for your outdated feeding hardware. The articles in this series contain actionable, knowledge-based tips to help you achieve your goals. While they contain information about complicated, biological processes, all the articles are written in plain English so that anyone can understand them. I encourage you to share these ideas with the people around you so that, in time, our individual cognitive conquests can become collective. As more and more of us start to take control of our behavior, society will gradually take the shape of a place that fosters health and happiness for all of its inhabitants.