Dear Dietitian,

I enjoyed your recent article on trans fats. You mentioned that we should choose monounsaturated fats and polyunsaturated fats -- what’s the difference?

--John

Dear John,

I’m glad you found the information on trans fats helpful.  Just as with the term “trans,” “mono" and “poly” refer to the chemical structure of the fat molecules. Saturation is a chemistry term that indicates how the carbon atoms are bonded together.  A fat molecule that is saturated contains carbon:carbon single bonds, and the remainder of the carbon bonds are filled with hydrogen. Thus, the carbons are said to be saturated with hydrogen. With monounsaturated fats, there is one carbon: carbon double bond; therefore, the molecule is does not contain the maximum number of hydrogen atoms, making it unsaturated. Polyunsaturated indicates more than one carbon:carbon double bond.

Generally speaking, saturated fats are solid at room temperature.  These are found in animal products, coconut oil, and palm oil. Saturated fats increase your cholesterol level, thereby increasing your risk for cardiovascular disease (CVD-heart attack, stroke).  There have been recent studies that suggest that the type of saturated fat in dairy products do not increase the risk for CVD, but more research is needed before this is conclusive.

Monounsaturated and polyunsaturated fats are liquid at room temperature. Monounsaturated fats are found in olive oil, canola oil, and nuts, while polyunsaturated fats are found in vegetable oil and seeds, as well as fish oil. These oils are considered heart healthy because they do not increase your cholesterol level. 

Enjoy your food and be healthy!

Dear Dietitian