Olive oil, coconut oil, sunflower oil, avocado oil, peanut oil, rapeseed oil, argan oil - So many possibilities! But which one to choose?
The answer in a nutshell is that they all are culinary and nutritionally interesting and thus, have their place in a healthy diet when used in moderation.
But some are more beneficial than others. The way you cook them can alter them, so this should be taken in account when choosing your oil. And finally, your taste matters!
1. Fats are wonderful products that our body needs:
They provide and enable the absorption of key vitamins (A, D, E and K)
They provide essential compounds that our body needs and cannot synthesise by itself (omega 3 and 6, flavonoids, carotenoids, stanols/sterols, glucosinolates), and play a protective role against cardio-vascular risks.
They enhance the taste of many foods, including vegetables that otherwise could be bland - as a result, children might be more encline to eat their veg.
But they have a few down-sides:
They are calorie-dense: there is more than twice as many calories in 1g of fat (9 kcal) compared to 1g of proteins or carbs (4 kcal)
Many culinary oils are fragile and can be denatured by heat, light, exposure to oxygen. (e.g., light will damage the vit E content)
Some may have deleterious effects on our health: high saturated fat diet are associated with increased cholesterol level
2. How much fat to include in our diet
30-35% of your energy intake should come from fat, which is aligned with the intake in the average diet in the UK (35% of energy intake). So yes, we should be mindful of how much fat we eat but rather than the amount, it is the quality, i.e. the types of fat, that we need to take into consideration.
Keep saturated fats under control: no more than 10% of your energy intake (circa 200kcal for women; 250kcal for men; 150kcal for children)
Prefer both mono-unsaturated fats (such as olive, avocado oil) and poly-unsaturated fats (e.g., sunflower, soy bean, rapeseed oil), and remember that diversity is crucial in order to get all the nutrients we need.
3. Knowing which oil to use rather than another
Of course, taste will be an important component in the choice of oil. Coconut oil is great in a curry but not so nice if you are making pancakes!
A crucial characteristic to take on board is the oil's resistance to heat. They do not all react the same way, so it is important to choose the right one depending on the cooking process.
For example, an extra-virgin olive oil will be a great choice as a salad dressing, but it will not be a good oil for cooking. For this, a refined olive oil or a rapeseed oil will be more adapted.
I have included below a table with various oils and advice on how to use them at their best but if you want to keep a limited array of oils in your cupboard, here are my day-to-day go-to oils:
Extra-virgin olive oil for salad dressing or a drizzle on pasta
Refined olive oil for roasting or braising vegetables
Rapeseed oil for pan frying fish or meat
Sources:
Foster et al (2009). Culinary oils and their health effects, Briefing Paper from British Nutrition Foundation.
Ferrières (2004). The French paradox: lessons for other countries. Heart
De Souza et al (2015). Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. The BMJ
British Nutrition Foundation (2016), FAQs: Coconut Oil, https://www.nutrition.org.uk/attachments/article/710/Coconut%20oil%20FAQ%20branded.pdf