One of the main implications of the theory of evolution is that if a trait is prevalant among the majority of the human population now, it means individuals that possessed the trait during our evolutionary history enjoyed some advantage, in the process of survival and replication, over those who didn’t. This arguably obvious conclusion leads to some very non-obvious insights once we expand the definition of a “trait” to its full potential.
A commonly cited trait is the existence of opposable thumbs whose evolutionary advantages have been well explored in the past. Things become interesting once we start looking at behavioral traits instead of merely the physiological ones. For example, feeling hungry when starved is a behavioral trait found in almost every human being and its evolutionary advantages are clear. Sexual attraction is another easily explained universal trait.
We can also get into the specifics of hunger and explore exactly what kinds of food are coveted the most. In most cultures around the world, the foods most sought-after happen to be either sweet or deep-fried, i.e., high-calorie, high-sugar food. This seems to suggest that individuals that enjoyed high-calorie high-sugar foods in the past had a certain advantage over those who didn’t. And yet, a person in the modern world who survives on a diet of donuts, fried chicken, and pepsi doesn’t survive very long. So what’s going on?
The paleo-diet hypothesis is that fast-food companies have hacked into the hunger-controlling part of our brain in order to maximize their revenues. Evolution has hardwired into us a program that goes: “If host is lacking in macronutrient X, make him want to eat food rich in macronutrient X. Otherwise, feel satisfied about the food situation.” How does the brain judge if something is rich in a certain macronutrient? From its taste and the smell.
If you wanted to make food that would motivate this hunger-controlling program to give you anything in exchange of it, the kind of food you would make would taste and smell exactly like the food the program desired without actually being like that food in terms of the macronutrients it contained. As a result, the body would eat and eat, but never be satisfied. This is exactly the kind of food produced by the fast food companies.
What does all of this mean? It means that fast food is bad because it does not contain the amounts of macronutrients our body desires. But everyone knew that. What it also means is that fast food smells and tastes like food that was supposed to be healthy for us. So if we could somehow ensure that the food we ate was not deceptive, i.e., it contained exactly the kinds of things it made our brain believe it contained through its taste and smell, then healthy food would taste as good as the modern unhealthy fast food. Or, in other words, if we only eat non-deceptive food, then healthy food is the same as tasty food.