Trans fats – What are They and Why Should I Care?


Q: What are “trans fats” and why are people making such a big deal about them? 

A:  In 2006, the Food and Drug Administration made it mandatory for food producers to list the amount of trans fat in their packaged foods.  New York City went a step further and banned all restaurants from using trans fats in any food production!

So, what’s the big deal?  Why would one little fat be banned by a whole city?  Let’s start with some definitions.  Chemistry majors can skip this part. 

All of the terms used to describe fat in our diet refer to their biochemical make-up:

Saturated fats are fats whose carbon molecules are “saturated” with hydrogen atoms.  These fats are solid at room temperature.  Think butter, cheese, meat.

Unsaturated fats have some carbon molecules without hydrogen atoms attached to them.  They are liquid at room temperature and can actually be good for you in moderation.  Think olive oil, fish oil.

Trans fats are produced when oil is exposed to hydrogen under pressure.  This industrial process decreases the number of double bonds in the molecule and/or converts them to the “trans” position.

Trans fats are everywhere – crackers, cookies, potato chips, processed baked goods, margarine, restaurant kitchens, the list goes on and on.  Why?  They have a higher melting point than natural fats and oils, which increases their stability.  This allows them to give products a longer shelf life and to withstand repeated heating and cooling – perfect for frying foods over and over.

While they’re good for business, they’re terrible for our health!  They do bad things to our cholesterol levels which increases our risk for heart disease, stroke and diabetes.  According to the Harvard School of Public Health, increasing the amount of trans fat you eat in a day by just 2% – about the amount in a medium order of fries – increases your risk of coronary heart disease by 23%!  I don’t know about you, but that’s more of a gamble than I’m willing to take for some fries!

Ideally, you should eat less than 2 grams of trans fat per day.  To put that in perspective:

  • A large fry at McDonald’s – 8 grams of trans fat
  • 4 Girl Scout shortbread cookies – 4.5 grams of tans fat
  • 3 -piece KFC Extra Crispy Combo Meal – 15 grams of trans fat

A couple of things to remember:

  • Food manufacturers can label a product as “0 grams of trans fat” as long as there is less than 0.5g per serving.  If you read the fine print, a serving size can be ridiculously small – say, 16 chips.  So if a product contains 0.4 grams of trans fat per serving and you eat 5 servings (which is easy to do) you will be getting 2 grams of trans fat from a product that says it has none.
  • Another term for trans fat is “partially hydrogenated vegetable oil,” so if you see that on the ingredient list, don’t be fooled.    

If you have any questions about what trans fats can do to your health, or what type of dietary changes you can make to avoid them, set up an appointment to meet with one of our nutritionists.  They’re happy to help.

Cheryl Czapla, Med IV
College of Medicine
The Ohio State University

Kathy Horava, DO
Student Health Services
The Ohio State University