Dear Dietitian – What effects do trans fats have on the body?

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Published Sunday, October 28, 2018
PICT Leanne McCrate Dear Dietitian
by Leanne McCrate, RD, LD, CNSC

Dear Readers,

We've all heard of trans fats by now, but what are they and what effect do they have on the body? "Trans" is a chemistry term that refers to the arrangement of molecules. In a trans formation, molecules are arranged on opposite sides of the carbon: carbon double bond.

Trans fats, which are unsaturated, are found in small amounts in animal products. The big offender has been artificial trans fats, like shortening, which contained partially hydrogenated oils. The good news is as of June 2018, artificial trans fats have been banned in the United States. 

Trans fats increase your LDL (low density lipoprotein), "bad cholesterol" while decreasing your "good cholesterol" - HDL (high density lipoprotein).  This in turn, increases your risk for heart disease.

As of 2006, the Food and Drug Administration (FDA) requires trans fats to be listed on the nutrition facts label. It should be noted that a food that has 0.5g of trans fats per serving can be labeled as 0 trans fat.

Since artificial trans fats have been eliminated in the US, some food manufacturers have created fully hydrogenated oils, but these contain saturated fat which should be limited. When cooking with fat, it is best to choose a polyunsaturated fat, such as corn or sunflower oil or a monounsaturated fat such as olive or canola oil, as these are healthier for your heart.


Dear Dietitian

Leanne McCrate, RD, LD, CNSC, is an award-winning dietitian with over fifteen years of experience. Have a question?  Email Leanne at may earn an affiliate commission if you purchase products or services through links in an article. Prices, when displayed, are accurate at the time of publication but may change over time. Commissions do not influence editorial independence.