My understanding from the literature is as follows. I may not have all 100% right but I think the ‘directionality’ is there.
Hope this helps.
First a need to provide important context.
- you should know that fats make the effect of carbs worse on the body. There is hormone interplay generated by carbs and fats that make them worse together than
On their own - I looked this up for a friend a few Months ago. At the same meal seems worse than part of the same ‘diet’ (a diet being a combination of macro nutrients- fats, proteins and carbs).
So when you hear ‘fats’ are bad it’s not an altogether false statement even though the media are now saying fats are good without context. In my mind it’s a bit disingenuous however because it’s really the carbs doing the damage: a diet with v heavy carbs content is unhealthy but a diet w heavy fat content is healthy. And yes there is science that shows this. The biochemistry also backs this up too - the endocrine hormonal effect is completely different for a carb heavy low fat diet vs a carb light high fat diet.
This is why if you choose fat as a fuel you should know about the various qualities. It’s a bit less true for glucose as a fuel because of the less healthful interplay of hormones I mentioned above. It is v possible that saturated fat is ‘worse’ with carbs than mono or polyunsaturated fat - I have not checked this so be mindful of this qualification. In other words the current saturated fat phobia may be completely justified in the context of the modern low fat high carb diet.
- so ... fats on their own - ie in the context of restricted carbs (incl protein) are v ‘healthy.’ There is a ton of research to show that inflammation goes down, cholesterol markers improve, blood pressure normalises etc. Also you can access your own body fat for fuel which you cannot do biologically if glucose is your main fuel. This is what I mean by ‘health’.
The ‘best’ fats in the context of fat as body fuel tend to be saturated because they are easier to break down. Doesn’t matter if animal or plant. Your body fat - which I hope you agree we should be using as fuel as often as possible - is saturated animal fat - I hope you agree nature would have made this safe to metabolise! Also think Omega 3 fats from fish. These should be good for you.
Next best fat type are those high in monounsaturated fat. Cold pressed oils like olive oil and avocado oil are great bc Relatively easy to break down.
Oils high in Polyunsaturated fats are those which tend to be processed - in some cases solvents are used to extract them. High in Omega 6 which I have read has strong associations with heart disease if you consume too much. Omega 6 is essential- you die if you don’t eat it but high proportions seem to be bad for you. Harder to break down. Soybean, corn, sunflower, safflower as examples. Makes sense that the body struggles to metabolise if a solvent had to be used to make them.
- finally trans fats are just poison and should never be eaten. Anything ‘hydrogenated ‘ you find in packaged food like crisps or peanut butter. Hydrogenated means humans added a hydrogen atom to make the food keep longer. Your body can’t break the rubbish down at all. Really should be illegal.