Back in the 1950s, American housewives were brainwashed; butter bad, margarine good. Butter consumption dropped, margarine consumption took off. So did heart disease.
But now we now that margarine is loaded with trans-fats, which aren’t found in nature and which has been linked to heart disease, among other maladies.
Not at our house.
My mother was a hospital dietitian, and would never allow margarine to be served under any circumstances. She knew what it was made from (petroleum)
We also got lots of beef.