This week, my studying is
all about fats. I think my head might be
fatter as a result. Here’s what I’ve
learned, plus some other comments.
In food, fat comes mostly
in the form of triglycerides. The more
saturated the triglyceride, the more solid the fat at room temperature. Saturation, in this context, has to do with the
chemical structure of the fat molecules.
If chemistry was a long time ago for you, like it was for me, let me
remind you that different atoms have the ability to bond with different numbers
of other atoms. In the case of carbon,
it can bond with more than one other atom, or it can bond with, say, another
carbon atom more than once. When the
carbon atoms in triglycerides form double bonds, the molecules don’t have as
many available bonds for hydrogen atoms and are thus less “saturated” with
hydrogen, less solid at room temperature, and, usually, better for us. One double bond among a triglyceride’s carbon
atoms makes it monounsaturated. More
makes it polyunsaturated.
The interesting part is
that most fats are mixtures of many triglycerides. We just categorize them by the kind they
contain the most of. Among the oils we
categorize as monounsaturated, we have olive, canola, peanut, and
safflower. Of those, canola has the least
saturated fatty acids and peanut oil has the most. This study and others like it suggest that
canola oil is a good choice for reducing cholesterol levels.
However, there are some
caveats. The best kind of oil to use
depends heavily on the use. Olive oil
breaks down at high temperatures. Peanut
oil doesn’t. If the goal is deep-frying,
olive oil is a bad choice. Most baking
does better with more saturated forms of fats.
I’m pretty sure that canola oil on toast is not going to be the next
craze when we are done with avocado toast (although why would we give up our avocados?).
Additionally, the reducing
effects of using monounsaturated and polyunsaturated fats are compared to using
saturated fats. In other words, it is
still possible to have too high a level of cholesterol while consuming only the
“healthier” fats.
Finally, all the
categories of fats have the same 9 calories per gram, regardless of saturation
level. Fats of all kinds are more
calorie dense than protein or carbohydrates and anyone wanting to reduce
overall calorie intake might want to take a look at cutting fat to remove
unneeded calories. (Leaving aside the
whole keto thing, which I have discussed elsewhere.)
As with all nutrition
information, it is important to consider the sources and also to consider the
effects of different diets in our own bodies.
Some of us do better on different kinds of diets than others. Information is only the start; we need to
apply judgment as we choose what to eat.