The High-Acid Secret: What Our Stomach pH Reveals About the Human Diet There is a growing conversation around the idea that humans evolved to thrive primarily on a carnivore diet. While this often feels counter-intuitive due to decades of conventional dietary advice, examining our internal biology—specifically our stomach acidity—provides a striking starting point for understanding our true evolutionary path. The pH Scale: A Logarithmic Tale To understand why stomach acid matters, we first need to remember that the pH scale is logarithmic . This means that a pH of 1 is 10 times more acidic than a pH of 2, and 1,000 times more acidic than a pH of 4. When we compare humans to other animals, we find ourselves in a very specific, and somewhat surprising, biological category. Where Do Humans Fit? Research into the evolution of stomach acidity has shown that a high level of acid is not just for breaking down food, but also acts as an "ecological filter...