As mentioned in my last blog, more and more scientists are proposing that humans have historically utilized fat as their primary metabolism.
For many reasons, it seems like a natural conclusion. I will list some of my thoughts, and then I will allow Chat GTP to weigh in to try to debunk my thoughts:
· Almost all cells other than blood cells can utilize glucose or fatty acids
· We have a minimal ability to store glucose as glycogen. We would typically run out of energy from glycogen within hours or a day.
· We can store weeks and months of fat as a reliable energy source.
· Our body creates all the glucose that it needs. This process is called gluconeogenesis, which makes carbohydrates unnecessary in our diet.
· This allows us to endure extended periods of scarce food, a remarkable survival advantage.
· As a species, we have survived ice ages, droughts, and all types of calamities that would have made plant life challenging to rely on.
So, I asked Chat GPT to see if my logic was consistent with the collected knowledge of the day. Here was its reply:
Yes, it is fair to argue that ketosis or a fat-adapted metabolic state was likely a more natural or primary physiological condition for humans throughout much of our evolutionary history. Several factors support this idea:
1. Babies Are Born in Ketosis:
• Newborns are indeed born in a state of mild ketosis, especially if breastfed, since breast milk is high in fat and relatively low in carbohydrates.
• This suggests that ketosis is a natural metabolic state early in life, indicating that humans are metabolically equipped to rely on fat and ketones from birth.
2. Ancestral Diets:
• For much of human evolution, particularly during the Paleolithic era, humans relied on diets that were primarily composed of animal fats, proteins, and seasonally available plants like fruits, nuts, and tubers.
• Carbohydrate-rich foods, such as grains and refined sugars, became widespread only with the advent of agriculture, about 10,000 years ago, which is relatively recent in evolutionary terms.
• Pre-agricultural diets likely had long periods of low carbohydrate availability, pushing early humans into ketosis frequently, especially during periods of fasting, winter, or food scarcity.
3. Intermittent Fasting and Food Scarcity:
• Early humans were often in situations where food was not consistently available, leading to frequent fasting and periods of low caloric intake.
• During these times of fasting or limited carbohydrate intake, the body would naturally shift into a ketogenic state, burning stored fat for energy and producing ketones for the brain and body.
• This is aligned with the concept that humans evolved to be metabolically flexible, using fat and ketones as primary fuels when carbohydrates were scarce.
4. Seasonal and Geographic Variations:
• Depending on geographic location and the season, carbohydrates from plant foods were likely not available year-round. In colder climates or during the winter months, humans would have relied more heavily on fatty meats and stored fat for energy, as plant-based carbohydrates were harder to find.
• This would have kept humans in ketosis for extended periods.
5. Modern Dietary Shifts:
• The shift to a carbohydrate-dominant diet happened relatively recently in human history with the advent of agriculture and more significantly with the industrial revolution, which introduced refined carbohydrates and sugars.
• Before this, the human body was likely more accustomed to relying on fats and proteins, making ketosis a common metabolic state for much of our existence.
6. Physiological Adaptation to Ketosis:
• The body’s ability to efficiently produce ketones and adapt to fat metabolism is a strong indicator that ketosis was a common state. Ketones are not just an emergency fuel but a highly efficient energy source that supports brain function and muscle activity.
• The fact that many organs, including the brain, can function optimally on ketones suggests that this metabolic state was likely critical for human survival during long periods of food scarcity.
Conclusion:
It is reasonable to propose that ketosis or being in a fat-adapted metabolic state was likely the default or primary metabolic state for humans over much of our evolutionary history. Given the limited availability of carbohydrate-rich foods, the cyclical nature of food availability, and the natural adaptation to fat metabolism (as seen in newborns and ancestral dietary patterns), ketosis was probably more common than the constant glucose-based metabolism seen today in modern, carbohydrate-rich diets.
This metabolic flexibility, particularly the ability to rely on fats and ketones for energy, likely conferred survival advantages during periods of food scarcity, making it an essential part of human evolution.
My logic and Dr. Ben Bikman's logic seem to hold up. It appears our native metabolism is derived from hunting.