Humans evolved eating animal fats, so our bodies work best with them.

Pro

Against

Evidence from Studies

Supporting (1)

Community contributions welcome

Oleic acid-enriched diet improves maternal lactation performance and neonatal growth through GPR40 and GPR120 signaling pathways

Randomized Controlled Trial

Animal

2025 Dec

This study shows that a healthy fat found in animal products like pork and dairy helps mother pigs make better milk and grow healthier babies, suggesting our bodies may be built to use these fats best.

Contradicting (3)

Community contributions welcome

Effect of prolonged feeding of differently saturated fats to laying hens on performance, blood pressure, plasma lipids and changes in the aorta

Cohort Study

Animal

1960

This study fed fats to chickens and saw how it affected their hearts, but it didn’t study humans or how our ancestors evolved to eat — so it can’t tell us if our bodies are best suited for animal fats.

Sea Lions Develop Human-like Vernix Caseosa Delivering Branched Fats and Squalene to the GI Tract

Case-Control Study

Animal

2018 May 10

This study talks about a waxy substance on baby sea lions and humans that helps their guts develop, not about what ancient humans ate. So it doesn’t tell us if we evolved to eat more animal fats.

Pleiotropic Effect of Human ApoE4 on Cerebral Ceramide and Saturated Fatty Acid Levels

Cohort Study

Animal

2017

This study found that a human gene variant (ApoE4) causes the brain to accumulate too much saturated fat when eating a high-fat diet, which may be harmful — suggesting our bodies aren’t perfectly adapted to lots of animal fats, contrary to the claim.

Similar Assertions

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

93%

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

90%

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

74%

A long time ago, as human brains got bigger, it might have been because our ancestors started eating more meat, eggs, and other animal foods rich in fats and cholesterol.

71%

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.

71%