Is there such a thing as fat-free fat?

Sounds like a silly question, doesn’t it?

We’ve all heard of foods like cakes and salad dressings – things that we would normally associate with fat content – becoming almost all completely fat-free, but surely fat itself cannot be fat-free.

Well, believe it or not, such a thing exists!

Here’s how it works.

Let’s start looking at a normal fat molecule (triglyceride):

An abbreviated form of this structure would look like this:

Where the RI, RII, and RIII are simply abbreviations for the long carbon chains. The length and structure of the carbon chains determine whether it’s an oil or a fat, and a host of other properties, but that’s another story.

For now, the important point is that the fats and oils that we eat are basically shaped like an “E” with a glycerol backbone, and three long strands (of fatty acids) coming off at right angles.

Now let’s consider the shape of our non-fat fat, a substance called Olestra, and explain how it works.

Let’s start by looking at the chemical structure of sucrose, which is ordinary sugar, that you put in your tea:

Now, with a bit of molecular engineering, we’re going to add some fatty acid chains to it, which is what Proctor & Gamble did in 1968, and hey presto, we now have Olestra:

Or we can use the abbreviated format:

So how does it work?

Well, it’s simple. When you eat it, your taste buds recognise the fatty acid chains and go “yum.”

But when it gets down to your stomach, your stomach says.  “What the hell is this stuff?  I can’t digests this!”  And anything that your stomach can’t digest , of course, gets sent “through to the keeper.”

Now, so far so good.  You’ve had the benefit of eating yummy, fatty food, without your stomach being able to digest it, and add it to your waistline.

But, unfortunately, having it all  “sent through to the keeper”  can cause a few problems.

Firstly, depending on how much you eat, it can give you a bad case of the trots.  Apparently if you eat it in normal quantities, this isn’t a problem, but it’s not too hard to see that the prospect of non-fat fat may attract people who will say “beauty, I can eat as many chips as I want”  and woof the stuff down in large quantities.

Secondly, it can cause vitamin deficiencies. The reason for this is that many vitamins are only fat-soluble.  We therefore need a certain amount of fat in our diet to enable these vitamins to metabolise.  Cutting fat out completely is never a good thing, and the problem with the Olestra is that it will all absorb all these fat soluble vitamins, but take them with it when it goes “through to the keeper.”

Thirdly, it can cause a condition known as steatorrhea, and if you are eating at the moment do not bother clicking on that link, as it concerns the final outcome of “sending it through to the keeper.”

So there you have it – non-fat fat.  Who’d have thought such a thing was possible?

Is this stuff in any food sold in Australia?  Not that I’m aware, but if you discover any, let me know.

1110cookie-checkIs there such a thing as fat-free fat?