It turns out that health wise, neither is very good.
They're critical of margarine, sometimes touted as safer for the heart than butter. However is margarine healthier?
"Both are associated with a great risk of heart disease, the butter and the margarine, for different reasons," said Lynn Tomilowicz.
Butter, is not only 100 percent fat, and has a lot of calories, but saturated fat makes up a lot of that. Saturated fat raises your cholesterol level.
Margarine is thought of by most as fake and was created originally as a cheap butter substitute.
It's also 100 percent fat, but some of these are transfats, which can increase your risk of heart attacks and strokes.
Most transfats in the American diet come from treating vegetable oil and used in cookies, potato chips and baked goods, to give them a longer shelf life.
Butter is not good for the heart, so what is left? What about natural oils, such as canola and olive oils? The unsaturated fats in these oils can reduce your blood cholesterol and protect the heart.
However, do not pour it on, as it is high in fat and calories.
You should take everything in moderation. If there is one takeaway message today, that is it.
Don't use just any oil. Though olive and canola olive are good for you, avoid coconut, palm and palm kernel oils. They are very high in saturated, unhealthy fats.