Before embarking on my first week long water fast in September of 2019, I watched countless videos of doctors and health experts who explained the miraculous benefits of prolonged fasting. Without fail, these experts would explain how “our bodies have evolved the ability to switch to fat burning as a secondary fuel source over millions of years of evolution.” The theory is that cavemen didn’t have access to fast food and grocery stores. Therefore, a caveman might be eating high on the hog one day (quite literally) but have to go a few days or weeks without eating before successfully hunting or gathering the next meal, especially when food is scarce.
In such scenario, what would happen if the caveman’s body didn’t have a back-up fuel source other than the food he just ingested? The obvious answer is that he would die or be killed because he’d lack the energy to avoid becoming a meal for another predator. It is then reasoned that because our bodies do have this amazing back-up fuel source that can last us in excess of 40 days without eating, not to mention the heightened mental clarity that comes with it, this feature must’ve evolved because our species did survive. Makes sense doesn’t it? Maybe, but then again, maybe not.
How would our bodies evolve the ability to have a back-up fuel source? In order to have a back-up fuel source, we’d first have to have a primary fuel source. If early man only had a primary fuel source and no back-up fuel source, unless he had a constant supply of food without interruption he would quickly die or be eaten. Dead things don’t evolve new and complex features.
Perhaps our modern secondary fuel source, our body fat, was at one time our primary fuel source. Since we can survive just fine using fat as a primary fuel source (which is the foundation of the Keto diet), why would we evolve another fuel source at all, much less evolve a secondary fuel source and then switch it to the primary fuel source?
Is there a perfectly good evolutionary explanation for all of this? Perhaps there is, but is the explanation based on evidence or theory? Do we have evidence in the form of early human fossils that were missing the ability to switch from glycogen to fat as fuel? I’m willing to bet my bottom dollar we do not. Finding a fossilized human is a rarity to begin with, much less one that has preserved body tissue to show internal organs. Most of the early human remains we have are not fossils at all, they’re skeletal remains found in dry regions where bacteria or animals didn’t completely destroy the bones. It would be pretty hard to prove that early humans could or couldn’t internally switch their fuel source when all we have are incomplete, dried-up skeletal remains. Of the fully preserved human remains we do have, like those frozen in ice or mummified, I bet they all have the organs necessary to have primary and secondary fuel sources.
When a doctor parrots the idea that fasting provides benefits to the human body as the result of evolutionary changes, did he or she actually do the research to find out if this is true or simply assume it is because evolution is assumed to be true? Paleontologists are experts in early human history, medical doctors or not. It is often assumed that because an expert in another scientific field of study stated a fact that the fact must be true because after all, that person is an expert, right?
There is another explanation for our bodies amazing ability to switch fuel sources that is rarely discussed in academia. The explanation is that if a complex system appears to be designed, that’s because it was. In order to believe in evolution, one must put aside the idea of “design”. Evolution is a blind process, not a mind. It knows no future, it knows no past, it has no plans or purpose, and it does not design. Design requires a designer.
An intelligent designer would’ve created our bodies to have a back-up fuel source from day one. Human designers can and do predict future possibilities and design systems to handle likely alternate scenarios. While everyone is free to accept evolution as being the process for the creation of everything, I chose the more obvious and simpler explanation of our bodies design being that of a designer.
When I started viewing my own body as an amazing piece of design and engineering, it changed how I thought about my own healthcare. If my body was designed, would it not follow that the world I live in was also designed to work with it?
In my related blog posts for being “fit after forty”, my foundation for health and fitness is focused on the belief that natural cures are better than unnatural cures, that my body can and will do amazing things if I take care of it, and that my amazing body is the handiwork of God, not chance and random mutations.