Many of us - especially if we were raised by dieters in the '70s and '80s -- grew up on the idea that fat is bad. You eat fat, you get fat, right? And eating too much fat could also raise your cholesterol and put you more at risk for heart disease. So for years, the answer for many was to avoid as many fats as possible.
But in the 2010s, the word is getting out that all fats are not created equal. Some types of fat, it turns out, can actually help lower your cholesterol and risk of heart disease. We know now that cutting out fat is not the answer -- fat gives us energy, controls blood pressure and helps keep us warm. It's also essential for absorbing certain vitamins into the bloodstream. With so many kinds of fat, though, how do you know which ones are the good stuff?
Let's get the bad stuff out of the way first. Trans fats and saturated fats have been (rightfully) getting bad press for years now. They're the culprits in high cholesterol levels, and our bodies can't easily convert them into energy. These are the fats that make you fat. Saturated fats occur naturally in red meat and dairy. There are small amounts of trans fats in red meat and dairy products, but they're mostly found in processed foods in the form of partially hydrogenated oils. The Food and Drug Administration is trying to ban trans fats from processed foods.
Now for the good fats. These are the ones your body puts to work, giving you energy and allowing you to make the most of the vitamins you consume. Unsaturated fats can lower your cholesterol and decrease your risk of heart disease. And there's no catch, except that you can't eat them willy-nilly. Even if you're filling up on the right fats, your fat intake should be no more than 20-35 percent of your total calories for the day [source: Zelman].
There are two kinds of unsaturated fats: monounsaturated and polyunsaturated. You'll find high levels of monounsaturated fats in olive, canola and peanut oils. Avocados, nuts and seeds are other great sources. Polyunsaturated fats, which help lower cholesterol, are primarily found in vegetable oils (corn, soybean and safflower, to name a few). Some kinds of fish, nuts and seeds contain a type of polyunsaturated fat called omega-3 fatty acids. Omega-3s, especially the kind found in fatty fish such as salmon, tuna and mackerel, have gotten a lot of press in recent years for their heart-health benefits and overall awesomeness for your body.
All fats, both good and evil, contain nine calories per gram, so one type of good fat isn't better than the other [source: Zelman]. Steering clear of fats found in processed foods, red meat and dairy is the most important step you can take. If you get most of your fats from plants - oils, nuts, seeds, avocados - and fish you're headed in the right direction.
- American Heart Association. "Monounsaturated Fats." Jan. 11, 2014. (July 9, 2014) http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Monounsaturated-Fats_UCM_301460_Article.jsp
- Harvard School of Public Health. "Fats and Cholesterol." (July 9, 2014) http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-and-cholesterol/
- WebMD. "Understanding Trans Fats." April 2, 2014. (July 9, 2014) http://www.webmd.com/food-recipes/understanding-trans-fats
- Zelman, Kathleen M. "The Skinny on Fat: Good Fat vs. Bad Fat." WebMD. (July 8, 2014) http://www.webmd.com/diet/features/skinny-fat-good-fats-bad-fats