The types of fats you eat are very important for your overall health and your ability to lose fat as well. In past decades, people were frequently told to keep fat consumption to a minimum, but that was pretty bad advice. Fortunately, people are generally more knowledgeable about basic nutrition and as you probably know, there are good (healthy) fats and bad (unhealthy) fats.
While many people realize fats, such as hydrogenated fats, are bad for you and other fats, such as Omega-3 oils, are good for you, fewer people are aware that cooking has a major impact on the healthiness of some fats.
In general, light, heat, and oxygen are the enemies of fats, particularly healthy fats. Healthy oils are often stored in dark containers to keep out light, processed using cold-processing techniques to keep down heat, and kept in air tight containers to keep out oxygen.
The more exposure fats have to these elements, the faster they degrade and the less healthy they become. Cooking is obviously a major source of heat and it can cause significant negative changes to certain fats, so it is very important to choose the right fats/oils to use when cooking.
To keep things simple, I will break fats/oils into three different groups: those that are truly unhealthy, those that are not too unhealthy, but can definitely make you gain fat, and those that are healthy.
The truly unhealthy fats, such as partially hydrogenated oils and trans-fats, should ideally not be consumed at all, so they should not be used in cooking either. The other two groups of fats are a little more complicated, so let’s take a closer look at both of them.
When it comes to cooking with healthy fats, the recommendations may surprise you. Most healthy fats are polyunsaturated, which means they are unsaturated at more than one place and structurally they have more than one double bond.
I will not go into too much scientific detail in this post, but generally speaking, the more unsaturated the fat (more double bonds), the more health benefits it has. The two fats with the greatest number of double bonds are the omega-3 oils found in fish (EPA & DHA), which are the healthiest fats on the planet.
However, while these fats are incredibly healthy in their natural state, cooking can ruin them and even turn some of the healthy fats into the very unhealthy trans-fats. Simply put, the more unsaturated the fat, the easier it can be destroyed or chemically altered during the cooking process.
When a double bond is heated too much, it structurally changes into a trans-fat. Therefore, a good general rule is the healthier (more unsaturated) the fat, the worse it is for cooking. In other words, don’t cook with polyunsaturated fats.
Now we are left with the third group of fats, which are not as unhealthy as trans-fats, but not healthy either. This includes fats and oils that are saturated or monounsaturated. Monounsaturated fats are similar to polyunsaturated fats, expect they are closer to being saturated (fewer double bonds).
These fats are a little healthier than saturated fats and more resistant to cooking damage than polyunsaturated fats, but they can still be damaged, especially under high heat and/or long cooking times. These fats can be used in cooking, although they are often not the best choice.
Arguably, the best fats for cooking are actually saturated fats. While it is true that saturated fats are unhealthier than they are healthy, they are really not all that bad when used in small amounts. When you consume saturated fats, there are only two things that can happen with the fat: your body can use it for energy or it will be stored as fat.
Since saturated fats don’t have any double bonds, they don’t have other physiological functions like unsaturated fats do, but this also means they can’t be structurally altered the way other fats can.
Even when cooked at high heat for long periods of time, a saturated fat can never be turned into a trans-fat, because a double bond is required for this conversion and saturated fats don’t have any double bonds. Therefore, using saturated fats is the only guaranteed way to avoid damaging the fat and creating unwanted byproducts, such as trans-fats, which are significantly unhealthier than saturated fats.
If you normally don’t eat much saturated fat, then using a small to moderate amount for cooking is really not a bad idea. It is definitely better than cooking with polyunsaturated vegetable oils, margarine, or anything else that contains partially hydrogenated oils and/or trans-fats. Of course, it is also important to keep your overall fat intake in mind, as saturated fats should be less than 10% of your daily caloric intake.
There is one specific fat that I have not discussed yet and that is olive oil. Olive oil is probably the healthiest fat you can do some cooking with, because it is primarily monounsaturated (1 double bond), so it holds up better to cooking than polyunsaturated fats. Plus, olive oil has health benefits from ingredients unrelated to its chemical structure.
Therefore, you can get a good mix of health benefits and minimal damage to the oil, but you still don’t want to fry anything or cook at high heat for long periods of time. The other drawback is olive oil can be overpowering and you can lose or change the taste of the food you are cooking.
As you can see, the fats/oils you use when cooking can significantly affect the health of the foods you eat and many fats that are healthy in their natural state actually become unhealthy during the cooking process. Ideally, you probably shouldn’t use very much fat when you cook anyway, but when you do, be sure to use fats that will hold up well during the cooking process and not turn into trans-fats.
14 years of experience and education in health and fitness