RIO Fitness Chicago® Exercise & Nutrition Blog

RIO Fitness Chicago® Tip:

Do you cook? If so, what kind of oils do you use? The oil you may be using might be causing you long & short term negative health effects like body fat gain or even cancer, depending on type, how you store it, and how high of a heat you're using. Continue reading for the break down on good & bad cooking oils.

The worst type of oil is an ingredient in packaged foods including some stick margarines, baked goods, chips, crackers and candy. I’m talking about partially hydrogenated oils—or trans fats, which is how they’re listed on Nutrition Facts panels on labels. Partially hydrogenated oil is vegetable oil that has been chemically altered so it’s less likely to spoil. Food manufacturers often add it to their products because it can help foods stay fresh longer.

Even in very small amounts, partially hydrogenated oil can wreak havoc on your heart health. It lowers levels of HDL (“good”) cholesterol and raises LDL (“bad”) cholesterol, and it even increases your risk for diabetes. The American Heart Association recommends that no more than 1% of your total daily calories come from trans fat. This translates to less than 2 grams for women, who typically need fewer than 2,000 calories per day. If a food contains trans fat, it’ll be listed below Saturated Fat in the “Total Fat” column.

Oils may be “fattening” in the sense that they’re pretty high in calories compared with other foods. All oils have around 120 calories per Tbsp, so you can easily gain weight if you use too much. Even butter has fewer calories than oil (100 per Tbsp of butter) because of its water content. What’s more, “whipped” butter sold in a tub has even fewer calories—about 60 to 70 per Tbsp, thanks to the air that’s been incorporated into the mix. And tub “light” margarine spreads have only 30 to 50 calories per Tbsp.

But since oils contain fats that are good for you, you’re better off getting that 120calories from a healthy oil rather than stick or tub butter. By the way, if you’re inclined to cut out fats entirely, don’t: We do need some fat to be healthy. Without it, our bodies can’t absorb fat-soluble vitamins like A, D, E and K, and we miss out on fatty acids that are essential for the health of your skin, hair, heart and brain—and just about every other part of your body.

When storing oil, heat, light and oxygen degrade oils, which makes them turn rancid more quickly and actually promotes the formation of cancer-causing compounds called free radicals. The more polyunsaturated fats an oil contains, the more susceptible to rancidity it becomes.

Oils rich in PUFAs, such as walnut and flaxseed, are best stored in the fridge in tightly capped containers. MUFAs, such as those found in olive oil, are a bit more hardy, but you should still protect oils that contain them by keeping the lid on tightly and storing them in a dark place far from the stove or other heat source. Saturated fats, such as butter, can withstand more heat, light and oxygen, but you should still refrigerate sat-fat–rich butter, because it contains milk solids, which can go rancid. If you store oils correctly, most will last about six months to one year.

When you’re shopping for oils, reach for bottles at the back of the shelf, since that’s where they are more protected from harsh lighting that can make them go bad. Check the bottle for an expiration date (most oils have one), and every time you open a bottle, give it a whiff to make sure it doesn’t smell rancid.

In short, when it comes to healthy oils choose: olive oil, safflower oil, avocado oil, coconut oil, flaxseed oil.