The fats in the modern diet look very different from the fats humans ate for most of history.
For most of that history, the primary dietary fats came from animals. Tallow, lard, butter, and the fat found naturally in organ meats and muscle. These fats carried fat-soluble vitamins, provided stable energy, and arrived in forms the body had always known how to use.
Over the past sixty years, those fats were systematically replaced. Vegetable oils made from soybeans, corn, canola, sunflower, and cottonseed now dominate the food supply. The shift happened gradually, driven by changes in food manufacturing, dietary guidelines, and the economics of industrial agriculture.
The question worth asking is not whether seed oils are the sole cause of modern disease. It is what we lost when animal fats stopped being the default.
What Animal Fats Actually Carry
The case for animal fats is not primarily about the fat itself. It is about what comes with it.
Fat-soluble vitamins, specifically A, D, E, and K2, require dietary fat for absorption. They are also found almost exclusively in animal fat. Grass-fed tallow contains meaningful amounts of vitamin K2, which is essentially absent from seed oils and most plant foods. Butter from pastured cows contains vitamins A and D alongside the fat that allows them to be absorbed. The fat in organ meats carries the same fat-soluble nutrients that make those organs worth eating.
When animal fats are removed from the diet and replaced with seed oils, two things happen simultaneously. The fat-soluble vitamins that rode along with those fats disappear from the diet. And the fats that replace them arrive without the nutritional passengers that made the original fats valuable.
The Omega Ratio Problem
Human diets for most of history maintained a ratio of omega-6 to omega-3 fatty acids somewhere between 1 to 1 and 4 to 1.
The modern Western diet has shifted that ratio dramatically. Estimates put the current average omega-6 to omega-3 ratio in the US somewhere between 15 to 1 and 20 to 1, driven primarily by the dominance of omega-6 rich seed oils in processed and restaurant food.
Omega-6 and omega-3 fatty acids compete for the same enzymatic pathways in the body. At the ratios seen in modern diets, the downstream compounds the body produces from these fats shift in ways associated with chronic inflammation. This is not a fringe position. It is a pattern documented consistently in research examining how the modern dietary fat ratio diverges from what human physiology developed alongside.
The ratio has changed more dramatically and more rapidly than at any other point in human history. That change tracks directly with the displacement of animal fats by seed oils.
What Changed and When
The shift away from animal fats was not random. It followed the widespread adoption of dietary guidelines in the 1960s and 1970s that identified saturated fat as a driver of heart disease and recommended replacing it with polyunsaturated vegetable oils.
Those guidelines were built primarily on studies that have since been criticized for their methodology. The original research conflated different types of dietary fat, did not account for the nutritional context of whole animal foods, and drew conclusions about causation from observational data.
The food industry moved quickly in response. Seed oils were cheap to produce, stable for shelf storage, and now had official endorsement. They replaced lard in baked goods, tallow in restaurant fryers, and butter in margarine. The transition happened across the entire food supply within a generation.
The people who grew up eating those foods had no idea they were participating in one of the largest uncontrolled dietary shifts in human history.
What This Means Practically
The goal is not to declare seed oils a singular cause of modern disease. The goal is to recognize what was lost when animal fats stopped being a default part of the diet and to replace what is missing deliberately.
Fat-soluble vitamins from animal sources. Vitamin K2 from grass-fed animals. The omega-3 fatty acids found in fatty fish and organ meats. The nutrient-dense fats that carried vitamins through traditional diets for thousands of years.
At Primal Being we think about this the same way we think about organ meats. Not as a correction to something broken. As a return to what has always worked. The fats our ancestors ate carried nutrients that mattered. Getting those nutrients back into your diet does not require a complicated protocol. It just requires paying attention to what replaced them and choosing differently.
