The Worst Fats for Diabetics

They lurk in many of the foods you love: movie theater popcorn, commercially made doughnuts, even coffee "creamers." And trans fats, also called trans fatty acids are so unhealthy that there's really no "safe" level—it's best to avoid them at all costs, particularly when you have diabetes.

Trans fats are widely considered to be the worst fat of all—worse even than butter. That's because they not only raise your "bad" cholesterol, but they lower your "good" cholesterol. And trans fats increases another type of fat in the blood called triglycerides. When you have a high triglyceride level, you run the risk of hardening of the arteries, which can increase your chances for stroke, heart disease and diabetes.  

Overall, you're at an increased risk for the development of heart disease if you consume trans fats on a regular basis. "And diabetics have a higher risk of heart disease anyway," explains Megan Fendt, RD, CDN, CDE of the Beth Israel Medical Center's Friedman Diabetes Institute in New York City. "Diabetics should never eat trans fatty acids."

Trans fats are, quite simply, a fat that the food companies put through a process called partial hydrogenation. "The process takes a liquid fat and turns it into a solid white, plastic looking fat," Fendt says. "Afterwards, that liquid fat looks like solid vegetable shortening."

Why would a food manufacturer be interested in turning a liquid fat into a solid white fat? Trans fat makes food last a longer time, so the shelf life is increased, for one thing. It tastes like butter, but it's cheaper, so the consumer is left with the illusion that the food companies are using something pricey in their product even when they're not.

Various meats and some dairy products could have very small amounts of trans fats naturally, but the harmful trans fats are the manmade ones, which are put into processed foods.

"The naturally occurring trans fats that we get from food aren't the ones we're concerned about," says Wahida Karmally, MS, RD, CDE, of
NewYork-Presbyterian Hospital/Columbia University Medical Center. "The partially hydrogenated fats are the ones that are so detrimental to your health."   

While food manufacturers now list trans fat on the nutrition label, they don't have to label any food that contains less than 0.5 grams of trans fats in a serving. That may seem like a small amount, but if you consume enough servings of a food that contains 0.5 grams of trans fat, eventually you'll be eating more than you might think.

Not sure how to know when a food has trans fats? Here's what to watch out for:

  • Beware of labels that says "partially hydrogenated" vegetable oil.
  • A food labeled as containing shortening should also be a red flag, since it, too, contains some trans fat.
  • While you might think that "fully" hydrogenated oil is worse than "partially" hydrogenated oil, it's actually not. Fully or completely hydrogenated oil does not have trans fatty acids. But to complicate matters even more, plain old "hydrogenated" vegetable oil could have some trans fat in it.
  • Some margarines contain trans fatty acids, so be sure to read the ingredient label carefully.
  • Some non-dairy creamers, and "fake" whipped creams also contain trans fats. Read the label, and choose a brand that is not made with "partially hydrogenated" vegetable oil.
  • Trans fats still are in use in some restaurants, but it's hard to know which establishments use them since they may not say so on the menu. The best way to avoid consuming trans fats when you dine out is to limit your consumption of fried foods. And remember, says Dr. Kelly Wirfel, clinical assistant professor of medicine at University of Texas Health Science Center Houston, it may pay to ask restaurateurs to stop using trans fat. "The more pressure we put on restaurants and other places to be transparent with what they are serving us, the better," Wirfel says.