All about fats

bell peppers

The good and the bad

When you're trying to lose weight, it can be tempting to cut out all fats, which have more than twice the calories of proteins or carbohydrates. But fat plays an important role in a healthy diet.

Fat helps you:

  • feel full and satisfied, so that you don't overeat
  • absorb important vitamins, such as A, D, E, and K

There are 3 main types of fat: unsaturated, saturated, and trans fats. By understanding the different kinds of fats, you can eat a healthy amount of it and still meet your calorie goals.

Good fats

Unsaturated fats can lower cholesterol, a fatty substance made by your liver and found in food. (There are 2 types of cholesterol: "good" HDL cholesterol that helps to unclog arteries, and "bad" LDL cholesterol that clogs arteries and increases risk of heart attacks.)

Unsaturated fats are usually liquid at room temperature. Look for these types of unsaturated fats in recipes and prepared foods, and eat them in moderation as a healthy part of a balanced diet:

  • monounsaturated fats: found in nuts and avocados as well as in olive, canola, and peanut oils — can lower "bad" cholesterol
  • polyunsaturated fats: found in soybean, corn, sunflower, sesame, and safflower oils — can lower "bad" cholesterol but may also slightly lower "good" HDL cholesterol
  • omega-3 fatty acids: found in fish, ground flaxseed, chia seeds and walnuts — makes your blood less likely to form a clot, stabilizes your heart beat and slows the build-up of plaque in your arteries. All of these things may help decrease your risk of a heart attack or stroke.

Fats to avoid

Saturated fats are solid at room temperature and should be limited because some can raise your "bad" cholesterol level, and increase your risk of heart disease.

Check labels and recipes for these sources of saturated fat:

  • butter
  • cheese 
  • ice cream
  • whole milk
  • beef
  • pork
  • palm oil
  • coconut oil

You can reduce the saturated fat you eat and stay within your calorie limit if you choose olive or canola oil, reduced-fat dairy products, and lean meats instead of those high in saturated fat.

Trans fats are unsaturated oils processed to make them solid. They raise levels of "bad" LDL cholesterol even more than saturated fats, and they lower "good" HDL cholesterol. They may even be linked to an increased risk of diabetes. The Food and Drug Administration has determined that trans fats are not “generally recognized as safe."

You may find trans fats in:

  • fast foods, such as french fries or apple pie
  • packaged foods, such as crackers
  • store-bought baked goods, such as pie and donuts
  • margarine made with partially hydrogenated oil

Always read the ingredient list and choose foods without partially hydrogenated oil.

How much fat is okay?

There's room in every diet for healthy fats, so enjoy them in moderation.

Ideally, 25 to 35 percent of your calories should come from fat, although the types of fat you eat make the biggest difference in your health. Try to choose the healthy fats, such as olive and canola oil, limit saturated fats, and avoid trans fats as much as possible.

Unsure about how much fat is in your favorite food? Read food labels, check nutrition reference books, or search the U.S. Department of Agriculture's websiteKaiser Permanente is not responsible for the content or policies of external Internet sites, or mobile apps..

Reviewed by: Carole Bartolotto, MA, RD, April 2016
Additional Kaiser Permanente reviewers

© 2016 Kaiser Permanente

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