What is saturated fat really?

neanderthin

I currently try to avoid it as much as possible - because to me it reads as plastic/margin/processed/toxic however, I haven't really stopped to think about it. Is there a "good" saturated fat - like there is for regular good fat in avocados?

Seems like you're a little confused about what saturated fat is actually. The plastic/margarine/processed/toxic fats you are thinking of are TRANS FAT, not saturated fat. Trans fat is the partially hydrogenated fat that is in margarine, etc.

Also, what do you mean by "regular good fat in avocados"? There is no "regular" fat. There are different kinds of fats. The kind in avocados is mainly monounsaturated. Saturated fats are found in larger quantities in meat and dairy and are as natural as the kind found in avocados.

Funny, there's equal amounts of saturated fat in avocados as there is in pork tenderloin on a gram for gram basis. Even though as you say, is a great monounsaturated source of fat.

richardheath

Strictly speaking, a trans fatty acid IS an UNsaturated fatty acid. However, it has a different shape to the "good" ones, which are actually cis-UNsaturated fatty acids.

trans-UNsaturated fatty acid = straight


cis-UNsaturated fatty acid = crooked


To make a trans-fat, hydrogen is added to a cis-fat, reducing the double bonds (the "unsaturation") to single bonds (and the chain is now "saturated" with hydrogens - it has as many as it can hold). Complete hydrogenation results in saturated fats. Partial hydrogenation results in some of the double bonds being reconfigured from cis to trans. The actual amount of hydrogenation that occurs will change the melting temperature of the fat and can be controlled to produce spreadable margarine etc.

Trace amounts of trans-fats do occur naturally (in animal sources), therefore it is very hard to remove them completely from our diets. But the partially hydrogenated fats used in the food industry provide no nutritional benefit and may (see caveats in other posts) have deleterious effects, so should probably be avoided.


Edit for image size + 'cos I made a very stupid mistake!

The_Enginerd

Saturated fat has been given a bad rep over the past few decades, and it really does not cause all the health problems people think it does. Saturated fats in moderated doses are necessary and healthy. It's not so much saturated fat that you should be concerned about, but trans fat. I try to eliminate all trans fats from my diet. Trans fat has been manipulated and processed, and isn't found naturally in any foods. Granted, I eat mostly Primal/Paleo so it's not hard to eliminate trans fats if you don't eat much processed food

Trans fats do exist in the fat and milk of ruminants, but at much lower levels than is seen in partially hydrogenated plant fats.

neanderthin

Strictly speaking, a trans fatty acid IS a saturated fatty acid. However, it has a different shape to the "good" ones, which are actually cis-saturated fatty acids.

trans-saturated fatty acid = straight


cis-saturated fatty acid = crooked


To make a trans-fat, hydrogen is added to a cis-fat, reducing the double bonds (the "unsaturation") to single bonds (and the chain is now "saturated" with hydrogens - it has as many as it can hold). Complete hydrogenation results in saturated fats. Partial hydrogenation results in some of the double bonds being reconfigured from cis to trans. The actual amount of hydrogenation that occurs will change the melting temperature of the fat and can be controlled to produce spreadable margarine etc.

Trace amounts of trans-fats do occur naturally (in animal sources), therefore it is very hard to remove them completely from our diets. But the partially hydrogenated fats used in the food industry provide no nutritional benefit and may (see caveats in other posts) have deleterious effects, so should probably be avoided.


Edit for image size

I believe the bottom fatty acid chain shown is not saturated but a cis configuration of an unsaturared fatty acid and the above example is what happens after it's partially hydrogenated, I believe.

richardheath

Ooops! I missed out all the UN's from my post! Good catch! Going to see if I can edit it...

neanderthin

No problem, you had me second guessing myself for a minute, easy mistake to make.

stealthq

...

My IMPRESSION (and I don't have a citation for this just now) is that they haven't yet figured out exactly what the detailed nature of the correlation/causality is between lots of satured fat, obesity, and heart disease is, but we know that there is one (inasmuch as overweight people who eat alot of saturated fat have a higher risk of heart disease) . So, I think you're right, there's more in play, whether its macronutrient balance or something else. Just carrying alot of extra body fat has alot of implications for many different metabolic functions, so I don't see why it should be surprising if the metabolism of saturated fats turned out to be one of them.

On the other hand, steak.....yum.

But, see, that's the problem with relying on correlative (epidemiological) studies. We don't know and can't know that there is any causality between lots of saturated fat, obesity, and heart disease even though it logically appears that there must be. Why? Because there are a ton of other confounding factors that aren't taken into account. They can't be - there are too many and some we undoubtedly aren't even aware of yet. Any one or combination of these confounding factors might be the actual causative factor\s with saturated fat and obesity only being 'guilty by association'.

The best these studies can do is let us formulate a hypothesis of the causal factors, and hopefully design an experiment to test the hypothesis. Hard to do in this case.