In this week's podcast, we discuss the many benefits of eating an animal based diet. From an evolutionary perspective, eating a meat heavy diet was more advantageous compared to eating mainly plants. Today's society is loaded will easily acquired calories. There's a Starbucks or convenience store on every corner and you can get thousands of calories for a few dollars but this is a very unique time. For most of our evolution, the acquisition of calories was priority number one therefore we had to be efficient with how and what calories we acquired.
In nature, for humans, plant‐sourced calories cost 10 times the price of meat if it is available. Seasonal fluctuations in many plant species' hinder their reliability as a food source for a significant portion of the year. In contrast, animals are always available. They may get skinnier and fatter depending on the season but they are always available. Carnivory, therefore, would have been a more time‐efficient and reliable caloric source.
On top of that our guts are designed to eat meat. We have a very short colon and a very long small intestine. Human colons shrunk by 77% over the course of our evolution. We didn’t use our colon for fermenting because we didn’t have too. Most of our energy was from energy dense animal sources, which are absorbed in the small intestine therefore over time we slowly decreased the size of our colons.
The elongated small intestine is where sugars, proteins, and fats are absorbed. Sugars are absorbed faster in the small intestine than proteins and fats. Increased protein and fat consumption should have placed a higher selective pressure on increasing small intestine length. A long small intestine, relative to other gut parts, is also a dominant morphological pattern in carnivore guts.
This altered gut composition enables better animal food digestion but hinders plant food absorption.
This, and many other features of the human anatomy, show that humans evolved eating an animal based diet. To learn more about the benefits of eating meat and why humans evolved focusing on acquiring animal based calories, listen to this week's podcast.