It was also government intervention that caused food manufacturers to switch from natural fats to transfats. Not good.
One of the first commercial transfat products (Crisco) apparently came about as an attempt to produce a long-keeping, aesthetically acceptable culinary equivalent to solid natural fats. That’s at least the impression I got from an old promotional cookbook. If Uncle Sam was pushing this (for reasons other than military food supply) there doesn’t seem to be a clear reason for it.