This Is The One Oil Type You Should Stop Cooking With, Experts Agree (It Causes Gas & Bloating)

You may already be aware that cooking with processed oils (and eating a lot of processed foods) can make it difficult to lose weight, but certain options are worse for your health than others. If you have indigestion, inflammation, or other gut or digestive problems, doctors say this one type of frying oil could be to blame. We spoke with Reema Hannaford, a NASM-certified nutritionist and health expert, and Katie Krejci, MS, RD, LP, IFNCP, a registered dietitian, to learn more about cooking with oils and how it might be a barrier to good weight reduction.

In Hannaford's experience, seed oils, such as those derived from grapeseeds, soybeans, peanuts, and canola, are the "very worst irritating oils to cook with." "They contain little to no nutrients and induce inflammation in the body due to the large amount of processing they go through," she notes, adding that anyone attempting to lose weight should avoid palm and vegetable oil for the same reasons.

These types of cooking oils, according to Krejci, are high in unsaturated fat. "Unsaturated fats contain one or more double bonds, making them liquid at room temperature (and thus less stable)," she explains. Unsaturated fats' double bonds are broken when they are exposed to intense heat. This oxidation is accelerated as a result of the breaking (release of free radicals).

According to Krejci, these cooking oils are high in unsaturated fat. "At normal temperature, unsaturated fats contain one or more double bonds, making them liquid (and thus less stable)," she explains. When unsaturated fats are subjected to high temperatures, their double bonds are broken. As a result of the breakage, this oxidation is increased.

"Free radicals are extremely harmful to the human body, causing inflammation, premature aging, as well as cellular membrane, mitochondrial, and DNA damage," she claims, citing academic papers and personal experiences. Because they lack double bonds, saturated fats are "far more stable and less inflammatory when heated," she claims. At room temperature, the fatty acids stack nicely together, which is why it is solid. "They have a high smoke point of 350-450 degrees by nature."

Most of the oils on the market today, according to Krecji, are heavily processed using huge pressure and high heat to extract the best yield possible. "High-heat exposure not only produces free radicals, but it also denatures naturally occurring vitamin E (an antioxidant)," she notes. This implies that manufacturers can add their own synthetic antioxidants (BHA, BHT, and TBHQ), which, as she points out, "have endocrine-disrupting effects." "On top of that, the oil is occasionally treated with a solvent (usually hexane)." Finally, these low-cost oils are frequently stored in a plastic bottle, which causes the oil to leach.

What To Use Instead & How To Prepare These Oils Healthily

Less-processed oils, such as unprocessed olive oil, avocado oil, and cold-pressed coconut oils, are recommended by both experts. "These oils maintain more micro-nutrients, are high in antioxidants, and health-promoting monounsaturated fatty acids," according to Hannaford, which is fantastic news for your stomach and heart. She explains that less processing equals less inflammation."

Anti-inflammatory chemicals contained in minimally processed olive oil, such as tocopherols, carotenoids, and polyphenols, support excellent health, she notes, while the preservation of vitamins E and K aids in healthy bodily function, blood circulation, calcium metabolism, and heart health."

For high-heat cooking, Krecji recommends only using fats that are solid at room temperature (rich in saturated fats). "This includes grass-fed ghee, grass-fed tallow, pasture-raised lard, and cold-pressed & unrefined coconut oil," she writes, adding that "you should save your cold-pressed and unrefined olive oil for low-heat applications like salad dressings, dips, or sprinkling on pre-cooked meals."