If you’re eating a ketogenic diet, you should be targeting to get anywhere from 65-90% of your total caloric intake from fat, including those from cooking oils. For the average American this requires a significant shift in eating pattern, especially when you consider the prevalence of refined sugars and hidden carbs that trickle into our diets on a daily basis.
However, developing a healthy keto diet isn’t as simple as cutting carbs and replacing those calories with fat. The reality is that not all fats are created equal, and some are better than others. Nowhere is that more evident than when trying to find the healthiest cooking oils for a keto diet.
Why Cooking Oils are Important
Whether or not you’re on a keto diet, it’s important to choose the correct oil for the cooking application. Since a higher proportion of your total calories will originate from fat when on a keto diet, it’s even more important to choose wisely. You’ll want to make sure you’re choosing oils that give you the most nutrient value, and that won’t break down at high temperatures and therefore induce inflammation.
To choose the healthiest cooking oils for a keto diet, you need look at an oil’s smoke point. The smoke point is the temperature at which a cooking oil begins to break down and degrade. As oils degrade they become carcinogenic, release free radicals, and can also trigger inflammation in the body.
Reducing inflammation happens to be one of the main reasons for following a ketogenic diet because it is a risk factor for obesity. So, it would be a huge mistake to use the wrong cooking oils for high temperature cooking and accidentally induce inflammation. Plus, as oils degrade they simply taste bad.
Guide to Cooking Oils
Low Temperature Cooking Oils for Keto Diet
Oils that have a low smoke point are best used at low cooking temperatures, such as a low temperature simmer, or used to apply to foods after cooking to add flavor.
Olive oil tends to be highly popular due to multiple health benefits. Many of these health benefits are believed to be the result of the polyphenolic compounds in olive oil which have antioxidant and anti-inflammatory activity[i] and could result in a lower risk for developing atherosclerotic plaques. In addition, studies have suggested that oleic acid, a primary component of olive oil, could directly reduce the levels of inflammatory markers[ii].
However, it’s important to recognize that these benefits are only associated with olive oils that contain a high polyphenol content. As olive oils are refined, aged, or cooked at a high temperature, they lose their antioxidant and anti-inflammatory compounds[iii]. For this reason, extra virgin olive oil is the best choice to get the most health benefits.
Extra virgin olive oil is primarily composed of monounsaturated fatty acids, and has a smoke point of 375° F, which is relatively low compared to other cooking oils. Given its low smoke point, it’s best used in recipes that require a low simmer like some vegetables, or as a base for homemade keto salad dressings.
As saturated fat has been removed from the public enemy list, butter has started to make a big comeback in cooking recipes. Grass-fed butter is great because it contains Vitamin A, D, E, and K2, and is high in conjugated linoleic acid (CLA) and sodium butyrate, which can help fight inflammation[iv]. Plus, butter is just plain delicious.
The main problem of cooking with butter is that it has a somewhat low smoke point of 350°F. This low smoke point is because it has a high water content and contains a small amount of lactose and proteins. If you want to cook at higher temperatures, you need to filter the butter to make ghee, which is discussed below.
However, feel free to continue to add butter to your keto coffee in the morning or in baking!
High Temperature Cooking Oils for Keto Diet
When you’re using high temperatures to fry, bake, or sauté you don’t want to worry about your oils breaking down, so it’s important to choose an oil that will resist degradation. There are a variety of cheap refined oils which will fit the bill, but they’re not the healthiest options. The following are three healthy high temperature cooking oils that are best for the keto diet, followed by two popular options that are not so healthy.
When you gently heat butter, you cause the milk solids to separate from the fat liquids. By separating those milk solids, you then create ghee, which has a higher smoke point than butter at 485° F. That means you can use it for higher temperature applications for keto recipes such as sautéing, baking, and frying. Separating the milk solids from the butter also gives the ghee a longer shelf life, which doesn’t require refrigeration.
Like butter, ghee also contains CLA, Vitamin A, K2, D, and E. In addition, most ghee is also absent of lactose, and casein which can cause stomach irritation in some people.
Due to it’s high composition of saturated fat (approximately 90%), coconut oil was previously demonized as an unhealthy cooking oil. But in recent years, as more studies cast doubt on the connection between saturated fat and heart disease, coconut oil is emerging as a super oil, especially for those on a ketogenic diet.
Coconut oil is primarily composed of medium chain triglycerides (MCTs), which are metabolized differently than long-chain fatty acids. These MCTs travel straight to the liver upon digestion, and are more quickly turned into ketones.
The smoking point for coconut oil is 450° F, which makes it stable enough for a variety of cooking uses for keto foods, including sautéing, baking, roasting and frying. One study showed that the quality of coconut oil did not deteriorate even after 8 hours of use at 365˚F[v].
On the keto diet you end up using a lot of coconut oil, so we buy ours in bulk from Amazon (affiliate disclaimer here). At only $18 for 2 lb, this organic, unrefined, extra-virgin coconut oil is our go-to for a cost-effective coconut oil. It's way cheaper than in stores.
Avocado oil shares several similarities with olive oil. Like olive oil, it’s high in monounsaturated fats, and it contains a healthy dose of antioxidants. However, unlike olive oil, avocado oil has an extremely high smoke point at 520˚F.
This makes avocado oil a healthy keto cooking oil for pretty much any application. You can use it for sautéing, frying, roasting or searing without having to worry about it degrading. Additionally, avocado oil is liquid at room temperature which makes it ideal for use in salad dressings and vinaigrettes.
Peanut oil is not typically considered to be a healthy cooking oil, largely because it contains a high amount of omega-6 fatty acids, which are often associated with inflammation. Although, there are some benefits to peanut oil. In particular, peanut oil is high in Vitamin E, an antioxidant which may reduce the risk of heart disease, as well as cancer[vi].
Typically, peanut oil is used for deep frying, because it has a high smoke point of 450° F and a neutral flavor. However, it’s still not a great option for deep frying because it’s composed of about 32% polyunsaturated fatty acids, which makes it more vulnerable to breaking down at high temperatures.
The recommendation here? Pass on the peanut oil especially when on keto.
Grapeseed oil is high in polyunsaturated fatty acids and a byproduct of wine making. One of the main benefits of grapeseed oil is that it can be used for high temperature cooking with a smoke point of 420˚F. It also has a light, clear taste which allows for easy pairing with other foods, without drowning out their flavor. It’s also cheaper than olive oil, so restaurants will often use it as a substitute.
However, grapeseed oil is not the healthiest cooking oil for a keto diet. Namely because grapeseed oil is high in omega-6 fatty acids. A high ratio of omega-6/omega-3 fats in the body can cause inflammation. Although it’s necessary to get some omega-6 fatty acids in your diet, most people get too much and not enough omega-3 fatty acids, therefore wreaking an inflammatory state in the body.
Like peanut oil, it’s best to pass on the grapeseed oil.
One last note when you're purchasing cooking oils at the store...
Cooking oils are classified based on their percentage makeup of saturated, monounsaturated, or polyunsaturated fatty acids. The makeup of fatty acid often affects an oil’s physical characteristics, so sometimes they can be identified based on how they look at room temperature. However, this isn't always the case like with butter and avocado oil.
When you're at the store, we recommend keeping a few oils in mind and forgetting the rest:
- olive oil and butter for low-temperature
- coconut oil, avocado oil and ghee for higher temperatures
Always purchase extra virgin, unrefined oils when given the option. This way you keep in all the good and know it hasn't gone through any type of processing. In addition, if a label says expeller-pressed or cold-pressed then these are preferred - the other option is through chemical extraction which is not healthy.
[i] Tripoli E, Giammanco M, Tabacchi G, Di Majo D, Giammanco S, La Guardia M. The phenolic compounds of olive oil: structure, biological activity and beneficial effects on human health. Nutrition Research Reviews. 2005 June; 18(1):98-112
[ii] Yoneyama S, Miura K, Sasaki S, Yoshita K, Morikawa Y, Ishizaki M, Kido T, Naruse Y, Nakagawa H. Dietary intake of fatty acids and serum C-reactive protein in Japanese. J Epidemiol. 2007 May;17(3):86-92.
[iii] Tallmadge K. Olive oil’s health benefits? It’s a slippery question. The Washington Post. 2012 September 11th
[iv] Säemann MD, Böhmig GA, Osterreicher CH, Burtscher H, Parolini O, Diakos C, Stöckl J, Hörl WH, Zlabinger GJ. Anti-inflammatory effects of sodium butyrate on human monocytes: potent inhibition of IL-12 and up-regulation of IL-10 production. FASEB J. 2000 Dec;14(15):2380-2.
[v] Srivastava Y, Semwal AD. A study on monitoring of frying performance and oxidative stability of virgin coconut oil (VCO) during continuous/prolonged deep fat frying process using chemical and FTIR spectroscopy. J Food Sci Technol. 2015 Feb;52(2):984-91
[vi] Rizvi S, Raza ST, Ahmed F, Ahmad A, Abbas S, and Mahdi F. The Role of Vitamin E in Human Health and Some Diseases. Sultan Qaboos Univ Med J. 2014 May; 14(2): e157–e165.