It's that salty sweet part of the chicken that you slurp up like Jell-O.  It's the part of your leg that bounces a little when you run.  It's that stuff that people on TV tell you how to get rid of.  It's fat.  If they are eating it up or trying to run it off, it seems people always want it to go away.  But just as you need your skin and your heart, you need fat to live too.  Let's see what the jiggle is all about.

Now this is going to taste good!


We have given fats a bad name.  This is too bad because living things really could not keep living without them.  Lucky for us, there's a more science-y word we can use.  Lipids are one of the four major kinds of building blocks that living things need to live because they make up the outside of all cells and they help us to keep energy for later.  They are made of the building blocks carbon (C), hydrogen (H), and oxygen (O).  For most people, this is science for "tastes good" or "I need to go to the gym."

I am guessing you do not hear the word lipid very often.  Instead you hear "fat free!" and "Need to lose some fat" and "Someone catch that fat! It's bouncing away!"   So maybe you will never hear that last one.  The word we use to talk about them is also the smaller part that make up lipids.   Fatty acids are the very small building blocks that do not break up in water and build together to make lipids.  All the fat in your body can be broken down into these.  You get them from the from the food you eat.  For some, fat tastes really good.  For others it's a pain, or a bulge, in the butt.  While you may not know what good these do, your body does.  Your body knows how to use them to make new cells and get the energy you need to live.  

When I say that fats keep you alive, I do not just mean that you will have a great Friday night if you eat pizza.  I mean, they really keep you alive.  Your body is made of lots and lots of cells.  They make your skin, your hair, they even carry your blood from place to place.  A cell membrane is the name for the two layers of fat that cover every one of your cells and other living thing's cells.  No, they do not need to go on a diet.  This is what separates them from the other cells and everything outside of them.  It's like your skin, keeping you safe and separating you from everything else.  This is like a skin for every cell in every living thing.  Do not try to diet your cell's skin away.

Eat your vegetables, eat your pizza.


As if keeping every one of your cells safe was not enough, fat does something else very important.  People keep fat all over their body.  (Some people might hear that and say, "Not me!  I have no fat in my body!"  Let's remember if this were true, this person would not be living.)  You keep it under your skin.  You keep some on your kidneys and in your liver.  Adipose tissue is the fat under your skin that your body uses to store energy.  When you need a boost, you can get it from your fat!  Not only does it keep your cells safe, it keeps you safe by giving you energy.  Just in case you need to run away from a lion, or something.

It's no use to chase after them. All those kids have the right amount of fat energy stores.


Fats aren't all bad.  They taste good, and more importantly, you need them to live.  They make a layer around the cells that make up every living thing, keeping their cells separate and safe.  Fats also make up your adipose tissue, which is where your body stores your energy that you need to do everything from run to breathe.  You will hear a thousand times to cut the fat, and it's true, you should not eat too much.  But always keep in mind that some of that jiggly stuff in your body is keeping you alive.  Be glad that your body is not "Fat Free."


References:

"Biology for Kids: Lipids and Fats." Ducksters. Technological Solutions, Inc. (TSI),  2014. <http://www.ducksters.com/science/biology/lipids.php>

Chem 4 Kids.  "Many Forms of Lipids"  Chem 4 Kids, 2012.  <http://www.chem4kids.com/files/bio_lipids.html>

Freudenrich, Ph.D., Craig.  "How Fat Cells Work"   HowStuffWorks.com, 2000.  <http://science.howstuffworks.com/life/cellular-microscopic/fat-cell.htm>