FOOD 101

The Skinny on Fats

By Robert L. Wolke
Wednesday, March 2, 2005

One of the most bizarre phenomena in the world of publishing is the extraordinary success of books purportedly written for dummies and idiots. Readers apparently aren't the least bit insulted by being so labeled.

I have been thinking that maybe I should try the dummy-and-idiot technique in my writing, despite the fact that I am privileged to have the most astute readers any writer could wish for.

But there is one topic that has been crying out for such treatment, because the public has not been able to grasp it in any other way.

I mean the topic of fats, where mass mystification still reigns.

So I hereby offer a sugar coated, deliberately oversimplified explanation "for dummies."

May the gods of chemistry and pedagogy forgive me.

Shape Matters

Like people, different molecules have different shapes. What distinguishes one biochemical molecule from another is mostly its shape. Chemical reactions occur when the molecules collide. Then they either stick together like jigsaw pieces or break into new shapes.

And there you have it: the shortest chemistry course in history. I'm going to explain all those fatty words in terms of the molecules' different shapes, because that's what makes them behave differently in our bodies.

FAT A fat is a particular type of chemical compound. Its molecules are shaped like a short flagpole with three long, starched streamers or pennants flying from it. The shapes of fat molecules--and hence their properties--differ from one another because the streamers themselves are different shapes. The flagpoles don't count.

What we popularly refer to as "a fat" in our diets, such as butter or vegetable oil, is actually a mixture of many kinds of fats.

FATTY ACID Those three streamers flying from the flagpole are fatty acids (FAs): long chains of carbon atoms with a couple of oxygen atoms at one end, tying them to the pole. Our bodies' metabolism breaks off the FA streamers, which are absorbed. Their exact shapes are what determine their healthfulness.

Common FAs include oleic acid, the primary FA in olive oil, and stearic acid, found in animal fats.

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