What’s interesting is that feedlot animal nutrition is one of the few areas where incentives are perfectly aligned with the truth.
Farmers make more money the faster and fatter an animal grows, so diets are tested relentlessly for efficiency, and the most effective intervention is actually implemented.
In multiple trials on monogastric animals such as pigs and chickens, researchers fed large amounts of coconut oil to them with the goal of increasing fat gain rapidly.
Funny enough, the animals fed coconut oil (mostly saturated fat) often became leaner, while animals fed seed oils like soybean oil gained more fat and showed a less metabolically healthy fat profile (despite similar "calorie" intake.)
Another possible explaination is from looking at this through a thyroid lens, fats also appear to follow a rough hierarchy:
the further a fat is from saturation, the more likely it is to interfere with thyroid function (and therefore stunt metabolic rate and health)
Saturated fats tend to be supportive
monounsaturated fats are mostly neutral
PUFAs are suppressive over time
Industrial trans fats are outright disruptive. (they have since been banned by the FDA)
If you see yourself as a lab rat you could test this for yourself, add in 1000 "calories" of seed oils vs 1000 "calories" of cold pressed raw coconut oil for a few weeks, I would bet my life that your body composition would be notably different in a positive way with the latter compared to the former.