trans fat

noun

variants or trans-fat

ˈtran(t)s-ˈfat 

ˈtranz-

plural trans fats or trans-fats

: an unsaturated fat that contains a trans-fatty acid molecule which has a trans arrangement of double bonds in its hydrocarbon chain and that either occurs naturally in the meat and milk of ruminant animals (such as cows and sheep) or is manufactured by hydrogenating vegetable oil to create a fat (such as margarine or shortening) that is solid at room temperature

The trans fats to watch for are the ones artificially produced and placed in prepackaged foods or commercially prepared deep-fried foods. These trans fats are introduced during cooking or during the manufacturing process to help extend a product's shelf life. They also help some foods taste more satisfying.

—Jennifer Moll

… if you are not minding your intake of another harmful fat called trans-fat, you might still be increasing your risk of heart disease. Indeed, whereas saturated fat raises the body's level of bad "LDL" cholesterol, trans-fat packs a double whammy by also reducing the good "HDL" cholesterol that protects against heart disease …

—Anne Tergesen

compare saturated fat

Examples of trans fat in a Sentence

Recent Examples on the Web

The first items in a list of CDC recommendations for preventing heart disease are all about food: Choose healthy meals and snacks high in fiber and limit saturated and trans fats, salt, and sugar. —Marianne Krasny, Forbes.com, 23 May 2025

Unhealthy oils are often high in saturated or trans fats, heavily processed, and prone to oxidation, producing harmful compounds and contributing to inflammation and heart disease. —Jamie Johnson, Verywell Health, 5 May 2025

Your diet can contribute, although there’s plenty of debate about which foods help or hinder (fiber, fruit, and vegetables are probably good; sugar and trans fats, not so much). —Alex Hutchinson, Outside Online, 8 Apr. 2025

One looked at how healthy a child’s diet was, giving more points for healthier foods, such as legumes, whole grains and vegetables, and deducting points for less healthy foods, including red meat and products high in salt and trans fats. —Lindsey Leake, NBC news, 7 May 2025

Word History

First Known Use

1974, in the meaning defined above

Rhymes for trans fat

• begat
• bobcat
• chitchat
• doormat
• ducat
• eclat
• format
• hazmat
• muskrat
• nonfat
• polecat
• thereat

Medical Definition

trans fat

noun

variants or trans-fat

: an unsaturated fat that contains a trans-fatty acid molecule which has a trans arrangement of double bonds in its hydrocarbon chain and that either occurs naturally in the meat and milk of ruminant animals (such as cows or sheep) or is manufactured by hydrogenating vegetable oil to create a fat (such as margarine or shortening) that is solid at room temperature

Consumption of red meat and trans fats is associated with an increased risk of laparoscopically confirmed endometriosis …

—Linda C. Guidice, The New England Journal of Medicine

Trans fat is created when manufacturers partially hydrogenate liquid oils to make them more solid, more stable, and less greasy-tasting.

—Nutrition Action Health Letter

compare saturated fat