Our bodies are built to use animal fats because that’s what our ancestors ate for thousands of years.

Human evolutionary physiology is adapted to metabolize and utilize animal-derived saturated and monounsaturated fats as primary dietary lipids.

Human evolutionary adaptation is optimized for the consumption of animal-derived saturated and monounsaturated fats as primary dietary lipids.

If you swap out natural fats from animals (like butter or lard) for man-made or heavily processed fat substitutes, your body might not get the special fat molecules it needs to keep cells healthy and send proper chemical signals.

Human metabolic systems lack evolutionary adaptation to high dietary intake of polyunsaturated fatty acids derived from industrial seed oils.

When people started replacing butter and lard with processed oils and fats, it took a long time for scientists to notice that this change was making people more inflamed and sick with long-term diseases.