“Foods humans did not evolve to eat are unhealthy.”
Strong confidence because human diets and genetics have changed across populations, and evolutionary age does not predict a food's health effect. Direct human evidence about the actual food matters more than a story about whether ancestors ate it.
A food is not healthy or unhealthy based on whether Paleolithic humans ate it. Humans use cooking, fermentation, agriculture and food processing, and populations have adapted to different diets.
Evolution can help generate hypotheses, but it cannot replace trials, cohort studies, toxicology and nutrition evidence.
Milk tolerance, starch digestion and many food practices vary across human populations and history.
Can newer foods or processing methods be useful?
Yes. Pasteurization, freezing, fortification and fermentation can improve safety, access, shelf life or nutrition.
You do not need to copy an imagined ancestral diet to be healthy.
Judge a food by what it does in humans, how it is used and how it fits your life, not by whether it is ancient.