The Pigs Got Shredded
A 1940s farming failure that explains everything about your metabolism
Farmers in the 1940s had a problem. They needed to fatten their livestock cheaply and quickly. Coconut oil was abundant and inexpensive, so they tried adding it to animal feed, expecting it to bulk the animals up.
It did the opposite.
According to Dr. Ray Peat, farmers attempted to use cheap coconut oil for fattening their animals, but found that it made them lean, active, and hungry. The animals were eating more, moving more, and getting leaner. This was a disaster for the farmers’ bottom line. So they went looking for something that actually worked.
They found it. In the late 1940s, chemical toxins were used to suppress the thyroid function of pigs, to make them get fatter while consuming less food. When that was found to be carcinogenic, it was then found that corn and soybeans had the same antithyroid effect, causing the animals to be fattened at low cost.
Read that again^
The goal was to suppress thyroid function. A suppressed thyroid means a suppressed metabolism. A suppressed metabolism means the animal gets fat on less food. More profit per pig.
And when the chemical method proved too dangerous? The highly unsaturated seed oils had the opposite effect of coconut oil, producing rapid fattening of the animal while decreasing feed consumption, so by 1950 corn and soybeans were widely considered to be optimal feeds for maximizing profits in the production of meat animals.
So why did coconut oil do the opposite?
The answer is the thyroid.
Coconut oil supports mitochondrial respiration, increasing energy production that has been blocked by unsaturated fatty acids. Since polyunsaturated fatty acids inhibit thyroid function at many levels, coconut oil can promote thyroid function simply by reducing those toxic effects.
Coconut oil is almost entirely saturated fat, which means it contains virtually no PUFAs. It has a general pro-thyroid action, for example by diluting and displacing antithyroid unsaturated oils. Its short- and medium-chain fatty acids sustain blood sugar and have anti-allergic actions, and it protects mitochondria against stress injury.
PUFAs, on the other hand, work in the opposite direction at nearly every step. Excess PUFAs inhibit various proteolytic enzymes that the body depends on to release stored thyroid hormones into the bloodstream. PUFAs block the body’s ability to deliver thyroid hormone to the cells, resulting in decreased cellular energy production. And excess PUFAs inhibit the enzyme necessary to convert T4 to active T3.
That last part matters. T4 is the inactive form of thyroid hormone. T3 is what your cells actually use. If the conversion is blocked, your thyroid panel can look “normal” on paper while your metabolism is crawling.
This is not a fringe theory. This is what farmers accidentally demonstrated in the 1940s, and then deliberately exploited for profit.
Now look at what we eat.
Soybean oil. Corn oil. Canola. Sunflower. Safflower. These are in almost every packaged food, every restaurant fryer, every “heart-healthy” spread that was supposed to replace saturated fat. We have been eating the livestock fattening formula for decades. And we have the chronic disease rates, the thyroid dysfunction rates, and the metabolic disorder rates to show for it.
Farmers began to use soy and corn oil to feed their livestock and found that this practice made the animals significantly fatter. The decrease in metabolic rate induced by adding significant PUFA to the diet allowed the animals to become fatter on less food, which translated to increased profits for them.
The same mechanism. Different species.
If you’ve been doing everything “right” and still feel like your metabolism is working against you, cold hands and feet, stubborn weight that won’t move, energy that crashes by noon, this history is worth sitting with. The food system was not designed with your thyroid in mind. It was designed around what made pigs profitable.
The pigs got lean on coconut oil. They got fat on the stuff that’s in your grocery cart.
