Fats and oils are a necessary part of cooking and nutrition. They conduct heat well, so food will cook more evenly when there is a layer of oil between it and the pan. Many flavour molecules are also soluble in fat and not water, which is why chefs say that “fat carries flavour”.

Nutritionally, many essential vitamins, minerals and fatty acids aren’t produced by the human body. We need to eat fats to get them and transport them around the body.

The problem with trying to have a sensible conversation about dietary fat is that many of us in the Western world are absolutely terrified of it. It’s a sentiment that’s far more recent than we realise.

It all started after World War II. The post-war economic boom meant that much of the United States, Western Europe and Australia ate more than ever before. At the time, those cuisines were mainly cooked with animal fats such as butter and lard.

By the 1970s, it became clear that Americans and Europeans who had been eating diets high in animal fats were developing heart disease at a much higher rate than before. The US released its first dietary guidelines in 1976, pointing the finger at animal fats and suggesting reducing those fats in the diet. The devil, however, is in the detail.

“Not all fat is created equal,” says Professor Luigi Fontana from the Charles Perkins Centre at the University of Sydney. “Vast differences exist in the composition of fats from plant and animal origin … Saturated fats found in meats and dairy products raise the blood levels of cholesterol. But extra-virgin olive oil, avocado, nuts and fish, which contain primarily monounsaturated and polyunsaturated fatty acids, do not increase cholesterol and protect the heart.”

There are other reasons to be wary of our intake of fat.

‘I don’t really want to say that any oil is bad because people cook in so many different ways.’

Professor Lauren Ball, University of Queensland

There’s the kilojoule content. A tablespoon of fat contains about 740 kilojoules and about 3 tablespoons a day will provide about 25 per cent of recommended daily kilojoules in an average 8400-kilojoule diet. That said, fat is a tool for cooking, and a lot of the fat we use ends up staying in the pan or on the plate rather than being eaten. Skimp on it too much, and you won’t be able to cook well.

There are also concerns around lipid oxidation. During storage and heating for cooking, fats will oxidise. There is evidence to suggest that oxidised fats and their products may be damaging to our health.

Lastly, there are questions that science still has to fully answer. These are things like the role of dietary linoelic acid (an omega-6) in inflammation or whether extra-virgin olive oil is better for your heart than refined olive oils. These ongoing areas of research are not scientifically settled, but unfortunately, this is where most of the misinformation is generated.

Lauren Ball is a professor of community health and wellbeing at the University of Queensland and, like me, is troubled by the amount of misinformation online about cooking oils. “I don’t really want to say that any oil is bad because people cook in so many different ways,” she says. “The important thing is finding the right oil for the right purpose.”

So which oils are the right ones for how we cook? Let’s look at some of the options.

Olive oil

Olive oil is a great cooking oil, and though much is made of its relatively low smoke point compared to other oils, that isn’t the whole story.

Olive oils vary widely in their quality and performance. The smoke point of extra virgin olive oil is often about 190C, but refined olive oils are about 220C or higher. Even so, while smoke point can be an indicator of potential for oxidation, for home cooking that’s less relevant than we might think.

At home, we generally heat oil once, for a short time, and at temperatures lower than the smoke point of the oils we use. A pan might reach 250C at the start of cooking, but after ingredients are added, the temperature drops substantially. In food manufacturing, oils might be repeatedly heated for hours or days, and so the oxidation of oils is far more a concern for processed food production than for home cooking.

Professor Fontana is a fan of olive oil. He calls it “the healthiest condiment” and recommends cold-pressed extra-virgin olive oil. “It’s an excellent sauce of vitamin E and other precious phytochemicals.”

I use extra-virgin olive oil a lot in my cooking, particularly when its flavour matches the overall profile of the dish, like in pasta, salad dressings, and Middle Eastern and Mediterranean dishes.

Vegetable oil

Vegetable oil is a generic term for many different oils, including canola, mustard, sunflower, rice bran, peanut, corn, grapeseed and many others. While there are many varieties, as they are refined for better cooking performance, the less distinctive they taste and the more similar they perform. As such, they can be used largely interchangeably.

There’s probably no type of oil as demonised online as vegetable oil. Anti-seed oil folks claim that the omega-6s in seed oils lead to inflammation in humans and that chemicals like hexane used in processing remain in the oil at levels that are toxic to us. Those claims aren’t supported by a reasonable look at the science.

In fact, science suggests that vegetable oils are a healthy source of unsaturated fats (like omega-6s) that are useful for reducing LDL blood cholesterol, blood sugar and the risk of heart disease. Hexane is used in the refining process of vegetable and olive oils, but residual hexane in food products is minuscule and not a health risk.

So, are vegetable oils bad for us? “Not really,” says Professor Ball. “We want people to be cooking with the oils that suit the food they are making, which helps people avoid processed foods … Trying to demonise specific ingredients is not very helpful in the context of an overall diet.”

Vegetable oil is easily the most used oil in my kitchen because of its neutral flavour, versatility and high performance in cooking. I use it for any frying, stir-frying and roasting, but I also use it in place of butter in baking to keep cakes more moist and healthier. Unrefined vegetable oils can be difficult to find and don’t perform as well with heat, but many have excellent and distinctive flavours.

Butter

About 70 per cent of the fats in butter are saturated (compared with about 14 per cent for olive oil and 7 per cent for canola oil). It also has a low smoke point about 150 degrees Celsius (250 degrees for ghee), which limits its effectiveness in cooking. But butter is prized for its flavour more than its performance, and in that regard, it really can’t be beaten.

I use it for basting pan-fried ingredients such as steak or fish to add flavour (after first searing with vegetable oil). Or brown it for its rich and complex nutty flavour. And nothing beats freshly baked bread with a smearing of good butter.

Coconut oil

A few years ago, influencers were touting coconut oil as a miracle cooking oil. Professor Ball isn’t so sure.

“Coconut oil is high in saturated fats,” she says. “But while there is some research that might indicate it also has some benefits to heart health, I’m not aware of anything that would suggest coconut oil is a better oil for cooking than any other.”

Besides being high in saturated fat, coconut oil has a strong flavour that limits its use. With healthier and more versatile unsaturated fat alternatives, I usually only use it when I want a very specific coconut flavour for South Asian and South-East Asian dishes.

Animal fats

While still used in some traditional recipes, strong evidence linking consumption of saturated animal fats with poor heart health has meant that cooking with fats such as lard, tallow, and suet has declined in recent years.

These fats add a huge amount of flavour, but they aren’t for regular use. One serving of potatoes roasted in duck fat or chips fried in lard won’t kill you, but you can definitely have too much of a good thing.

So, after all that, what oil should I be cooking with?

The short answer is: a variety.

Despite all the misinformation clouding the issue, the scientific consensus on oils has been remarkably consistent for decades. If you cook and eat a variety of foods, you should probably be cooking with a variety of oils, and for your health they should mostly be unsaturated fats.

I cook mainly Asian and Mediterranean foods at home, which means I mostly use vegetable oil and olive oil. I also spread butter on my toast, add whipped cream to pancakes and cook with rendered animal fats sometimes when I want that flavour.

As with most things, the key is nuance and moderation, but unfortunately, in the online world, these qualities are often in short supply.

Adam Liaw’s tips for cooking oils

• Unsaturated fats like those found in olive and vegetable oils are better for your health than the saturated fats found in butter, coconut oil and animal fats. I use these as the primary oils for cooking.

• Fats are high in kilojoules so they are best limited to reduce overall kilojoule intake, but you still need to use enough to be able to cook well.

• Use the appropriate oil for the dish you are making. Vegetable oils will generally perform best for cooking with high heat or where neutral flavour is needed. While extra-virgin olive oil does not perform as well in high heat and has a more distinct flavour, it is also fine to cook with. Cold-pressed and unrefined oils will have more flavour and contain more nutrients than heat-extracted, refined oils.

• With refined vegetable oils, the differences between different sources of oils such as canola, sunflower, rice bran and even olive are not hugely significant when it comes to home cooking.

• Moderation is important when it comes to saturated fats. As a healthy person with low cholesterol, I use butter and animal fats as secondary fats in my cooking when the dish requires them.