Apparently There is an Icon of Science Now

[tanarill]

But here's the science, at any rate:


You hear all the time about how mono- and poly-unsaturated fats are better for you, but have you ever wondered why? By the end of this, you’ll not only understand why unsaturated fats are better that saturated ones, you’ll understand why poly-unsaturated fats are better that mono-unsaturated ones.

It’s all about kinks. No, we’re not talking about sex. What you do behind closed doors is your own business*. But we’ll talk about rape, called canola in America because, unsurprisingly, few people in America are likely to buy something called “rapeseed oil.” We are also moving out of scientific shorthand for a bit.

Saturated fats are those in which the carbon atoms are carrying as many hydrogens as their tendency to form four bonds will allow. So it stands to reason that an unsaturated fat involves at least one carbon that isn’t carrying as many hydrogens as it could. Let’s explore. Here’s our hypothetical hydrocarbon again.

Now, imagine what would happen if removed a single hydrogen. Most of the carbons still have eight electrons, but there is one single unbonded electron, and C likes to have four bonds. So carbon will try to form another bond. We don’t want it to bond with hydrogen, though. So let’s remove a hydrogen from the carbon next door, and let the carbons form a second bond. Notice that each carbon still has four bonds.

This called mono-unsaturated, because even though there are two less hydrogens, there’s only one double bond. Poly-unsaturated fats are pretty much the same as mono-unsaturated fats, but have more than one double bond. When talking about unsaturated fats, you count the number of double bonds, not the number of hydrogens you’re missing.

But what is so special about unsaturated fats? For this, we have to think in 3D again. A saturated hydrocarbon looks like this:

|-/\/\/\/\/
|-/\/\/\/\/
|-/\/\/\/\/

A mono-unsaturated fat looks kind of like this:

|-/\/\/\/\/
|-/\-/\/\/\
|-/\/\/\/\/

See what happened? The double bond (which is shorter than a single bond in real life and goes in a different direction) offset the entire hydrocarbon, so that it zigged where the other zagged and zagged where the other zigged. The hydrocarbon is no longer able to stack, because the hydrogens are all in the wrong places now. In 3D, this is called a kink, referring to the sort you find in hair. The chain actually bends out of the screen, preventing it from stacking in 3D either**.

To deal with this, your body will go through some very complicated chemical reactions that break the double bond and add two hydrogens, saturating the fat and making it stackable***. However, it takes energy to do this. For every hundred grams of saturated fat you eat, you will gain 97 grams of weight, the other three being the energy your body uses getting it out of the food and into fat cells. If those same hundred grams were an unsaturated fat, you’d gain 70 grams of weight. Nearly 30% of the energy goes to saturating the rest of the fat.

Poly-unsaturated fats use more energy because your body has to saturate the fat before storing it. This is why vegetable fats are less unhealthy than animal fats; animal fats come pre-saturated, while olive oil is almost the only mono-unsaturated plant oil. However, lots of companies don’t like unsaturated fats because even though they taste good, they have some undesirable properties.

In fact, many companies will go to huge lengths, and trust consumer ignorance, to keep us from noticing how they . . .

*And given that I'm new at this entire relationship thing, I probably wouldn’t do it.

**Trans-fats don't actually keep fats from stacking so much, which is why they are more unhealthy.

***Your body doesn't pay much attention to trans-fats, see above.


That's all for today. Feeling kind of listless. Last bit tomorrow.