unsaturated fat

noun

plural unsaturated fats
: a fat (see fat entry 3 sense 2b) that contains a fatty acid (see fatty acid sense 2) molecule which has one or more double bonds in its hydrocarbon chain, that is liquid at room temperature, and that is found in many plant sources (such as nuts, seeds, and vegetable oils) and some fish
Research connects consuming moderate amounts of unsaturated fats with a slew of health benefits, most notably, lower risk of premature death. Unsaturated fats can help boost good cholesterol and lower bad cholesterol in your blood, which can lower your risk of heart disease or stroke …Cleveland Clinic
I found that brownies that contained mostly saturated fat (and thus lots of rigid carbon chains) baked up quite tender and not at all chewy, while brownies made with mostly unsaturated fat (and more flexible carbon chains) were the chewier ones.Andrea Geary
see also monounsaturated fat, polyunsaturated fat compare saturated fat, trans fat

Examples of unsaturated fat in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Peanuts contain several nutrients that may support blood vessel function, including unsaturated fats, plant protein, fiber, polyphenol and certain amino acids, the study authors noted. Khloe Quill, FOXNews.com, 3 Dec. 2025 Oils rich in unsaturated fats, like olive and canola, appear to support heart health, while butter, margarine, and some tropical oils may raise risks when eaten in large amounts. Sarah Jividen, Verywell Health, 28 Nov. 2025 Almond Butter Nut butters, like almond butter, are high in unsaturated fats. Merve Ceylan, Health, 18 Nov. 2025 Avocados are packed with vitamins, minerals, and unsaturated fats. Andrew Paul, Popular Science, 15 Oct. 2025 Instead of saturated fat, the current guidelines encourage eating foods that are high in unsaturated fat, including nuts, avocados and olive oil, which are linked to lower cardiovascular risk. Will Stone, NPR, 8 Oct. 2025 Schmidt recommends including foods with polyphenols, fiber, unsaturated fats and probiotics in your diet. Helen Carefoot, Flow Space, 17 Sep. 2025

Word History

First Known Use

1899, in the meaning defined above

Time Traveler
The first known use of unsaturated fat was in 1899

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Cite this Entry

“Unsaturated fat.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/unsaturated%20fat. Accessed 19 Dec. 2025.

Medical Definition

unsaturated fat

noun
: a fat (see fat entry 2 sense 2b) that contains a fatty acid (see fatty acid sense 2) molecule which has one or more double bonds in its hydrocarbon chain, that is liquid at room temperature, and that is found in many plant sources (such as nuts, seeds, and vegetable oils) and some fish
Foods from animal sources such as meat, milk, and eggs contain more saturated than unsaturated fats. Conversely, foods from vegetable sources such as the oils contain more unsaturated fat.Sue Rodwell Williams, Nutrition and Diet Therapy
"The data suggest that any oil that's high in unsaturated fats—whether it's polyunsaturated or monounsaturated—is associated with a decreased risk of cardiovascular disease," says Alice Lichtenstein of the U.S. Department of Agriculture …Bonnie Liebman, Nutrition Action Health Letter
see also monounsaturated fat, polyunsaturated fat compare saturated fat, trans fat
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