> the first group’s fat came primarily from vegetable oil sources like safflower oil and margarine while the second group’s fat came from sources like olive oil and butter.
Apparently the author does not consider olive oil to be a vegetable oil. Huh? As I understand it, a vegetable oil is an oil extracted from a plant and olives are the fruiting body of a plant.
Which is why some prefer to use the term "seed oil" rather than "vegetable oil". The main distinction though is that seed oils are mainly composed of polyunsaturated fats, unlike olive oil, coconut, avocado, butter, etc. Seed oils are often labeled "vegetable oil" on their containers.
Apparently the author does not consider olive oil to be a vegetable oil. Huh? As I understand it, a vegetable oil is an oil extracted from a plant and olives are the fruiting body of a plant.