Before 1950, heart disease was rare. Obesity affected less than 10% of Americans. Then something happened. Procter & Gamble had a problem. They had a waste product, cottonseed oil, cheap, industrial, inedible.
So they hydrogenated it, gave it a nice white color & called it Crisco. Then they did something genius & evil. They gave the American Heart Association 1.7$ Million. Suddenly, butter was the enemy & seed oils were heart healthy. Hospitals, schools & institutions replaced butter with margarine.
Cooks at home stopped using lard & butter & switched to seed oils. And within a generation, obesity, diabetes & heart disease exploded. That's not a coincidence.