Much Is Written And Promoted About The Various Sorts Of Fat. Your Body Isn’t All That Picky, But Cells Prefers Saturated Fat.

For years we were told to avoid saturated fat, and go for monounsaturated. Then polyunsaturated fat had its day in the sun. Now it appears that the long maligned saturated fat is the best one of all.

Confused? If not, read the previous paragraph again.

Let’s start out with some handy abbreviations:

MUFA=monounsaturated fat

PUFA=polyunsaturated fat

SFA=saturated fat

What is Fat?

So what is fat really? It’s a string of carbon atoms with hydrogen atoms stuck on.  It looks like this. The silver hydrogen atoms are covering the string of black carbon atoms.

All oil is fat. We usually think of oil as something that is liquid at room temperature, but as far as the body is concerned, it’s all fat.

All meat, and most vegetables have some fat content, and it is typically a mix of the three types: MUFA, PUFA ,and SFA, and each type comes in a variety of lengths. So in fact, there are dozens of different sorts of fats.

Fat Comes in Many Forms

Most of the fat we consume is in the form of triglycerides, which is, well, three fatty acids and a glycerol backbone.  Each glyceride can be made up any sort of fat molecule.

Here is a triglyceride with its three fat molecules.

All three molecules are SFA. How do we know they are SFA? Because they are straight.  MUFA and PUFA have kinks in them. The straightness is the reason saturated fats, like butter, are solid at room temperature: The straight molecules stack better and take up less room, so SFA is denser and therefore solid.

The thing connecting the fat molecules together with the red oxygen atoms is a glycerol molecule. This is the “glyce” in triglycerides. If you pluck the fat molecules off, you are left with a glycerol molecule, which the liver will likely turn into sugar.

The silver balls are hydrogen atoms, and are covering black balls—carbon atoms—which are barely visible. The drawing isn’t to scale. The hydrogen atoms are much tinier. If we could “see” such things at all, we could easily see the carbon atoms.  If there are as many hydrogen atoms as possible crammed onto those black carbon atoms, the fat is said to be saturated—saturated with hydrogen atoms.

If you pluck a few hydrogen atoms off, the adjacent carbon atoms will connect up with each other, and will form a kink. Then the triglyceride molecule starts to look like this.

Not so tidy.

Fat in the form of triglycerides doesn’t mix with water, and blood is mostly water, so triglycerides are not allowed loose in the bloodstream. Otherwise, they would cluster together and gum things up.

If you pluck a fat molecules off of a triglyceride, a couple of oxygen molecules will attach onto the broken end. It has then become a Free Fatty Acid, or FFA. These can float in the blood.

This is really quite a heap of different sorts of fats. There are three types, MUFA, PUFA, and SFA, and each comes in a wide variety of lengths, some bound up, three at a time, in triglyceride molecules, and other in the free fatty acid form.

How Does The Body Make Use Of All These Fats?

Is the body so flexible that it can directly use all of this huge variety? No, the body needs very specific lengths and types of fat. So then, does the body patiently wait for just the right type? Not it all. Instead, the body employs a tiny army of molecular butchers that take the fat, slice it up to the necessary length, convert it to or from MUFA,  PUFA, and SFA, and package it up precisely as needed. The tiny butchers are called enzymes, and they actually directly snip and modify the fat molecules. Enzymes usually end in –ase.  One such is called Fatty Acid Desaturase. Guess what it does?

Since we are designed to mainly use fat as energy, and also use it to build cells walls, it should come as no surprise that there are a large number of specialty enzymes in our butcher shop. Some convert the fats from the various types. Some pluck the fat molecule from triglycerides and tack on the needed molecules at the broken end, making an FFA. Others snip the long fat molecules into short pieces—fat briquettes if you will— that can feed the Krebs cycle, a sort of tiny furnace residing in our mitochondria, our basic cellular energy generators.

So the big picture here is that the body can slice and dice just about any fat we eat to meet its specific needs. So in a grand sense, it doesn’t matter that much which fat we eat.  However, there are a few caveats here worthy of consideration:

1. Saturated fat is slightly better:

• It is less subject to degradation—it keeps better.
• It is somewhat more versatile as a cell wall building material.
• It takes a bit less energy to snip it into the fat briquettes for energy production.

2. Trans-fat is really bad news. This is a man-made fat. The body is fooled and tries to use it, but uses it improperly. It increases heart disease and possibly cancer. An excess of 30,000 deaths per year were linked to it. Fortunately, it is all but gone from today’s diet. Keep in mind this bad news applies to man-made trans-fats; there are healthy naturally occurring trans-fats.
3. There are a couple of fats the body can’t make, or at least can’t make enough of: Omega-6 and Omega-3. These are fats with the kinks 6 or 3 carbons from the end. For some reason, the body has a hard time installing a kink there if needed, so we need to get these from food. Omega-6 is abundant, but Omega-3 a bit rare, fish being a good source. We need to get enough Omega-3. There is often talk of Omega-6 – Omega-3 ratio. Our hunter-gatherer ancestors probably got 1:1, but we are about 6:1. However, there is no real science supporting the value of the ratio. Just make sure to get some Omega-3.
4. Eat clean fat. This means organic vegetables and grass fed or wild meat. This is not the most financially economical way to eat, but try to lean in that direction when possible.

Superstitions Die Slowly

We suspect that today 90% of Americans believe saturated fat is bad for you. Hopefully our blog audience is substantially more enlightened. Saturated fat is actually good for you, and there is now no end of research proving that. It came to be bad primarily for political reason. For an in depth discussion of this, you might read “Good Calories, Bad Calories”, by Gary Taubes.In the meantime, enjoy your good healthy clean MUFA, PUFA, and SFA. Mix ‘em up. You need them all.
Oh, and by the way, fat won’t make you fat. The reasons are explained here.