Take 12 kg of bones, add 33 kg of muscles and 15 kg of fat. Mix it up with 20 kg of organs. Done. Now you have all the ‘ingredients’ to build up the human body.
Or do you? They say you’re what you eat, but do you recall eating half of the entire periodic table? They also say your body is 60% water… Where is all that water anyway? And what exactly makes up the remaining 40%?
Ever felt like a million dollars? What if we told you that all the chemical elements that make up your body are worth just about $160? No surprise there, since you’re mostly made up of…oxygen.
Of course, all bodies are different. Tall, short, old, young, fit and not so much… But we’re all just a bunch of molecules that happen to be doing some complicated things.
Or are we more than that?
It all comes to who you ask. A biologist would say you’re made up of around 100 trillion cells.
They’re constantly replicating, dying and getting replaced with the new ones. They also contain most of you body’s water.
More than half of those cells aren’t exactly your own. They’re bacterial cells. Many species of bacteria and other microorganisms live inside and outside of your body. Collectively, they weigh around 2 kg (4 lb).
But wait, don’t rush to wash your hands just yet. Not all bacteria are harmful. Actually, most of your microbes improve your immune system and the internal ones are vital for food digestion.
On the other hand, the human cells in your body form all types of material you’re made of. Those muscles you work so hard to build, and that fat you always meant to lose. Your bones, and your teeth, your brain and all your body fluids including blood and, well, urine.
However, if you ask a chemist what you’re made of, the answer will be very different. They’d give you a list of the chemical elements that built you.
A 70 kg (150 lb) adult has this many atoms. Let me save you from trying to count all those zeroes. There’re 27 of them! Or you could just say “seven billion billion billion”. That’s a whole lot of atoms. Your body contains at least 60 chemical elements.
For the most part, it’s oxygen and hydrogen forming H2O, or water. Then there’s the carbon that makes up all your organic compounds like carbohydrates, lipids, proteins, and nucleic acids. And nitrogen, that builds up your DNA.
Other elements, though important for supporting life, are found in very small quantities.
You’d be surprised how little iron your need – just 4 grams (0.14 oz). But still, that’s enough to transport all 40 kilograms (88 pounds) of oxygen around your body.
That’s right, 40 kg (88 pounds) of oxygen. 99% of the mass of your body is made up of just 6 elements. Of that, 65% is oxygen. Since all atoms are 99.9% empty space, technically, you’re made of nothing.
If we somehow managed to remove all that empty space from our bodies, the entire human population would take up the space of a single sugar cube.
If you wanted to be more poetic, you could say you are made of stardust. All the elements you’re made of, were once cooked up in the stars when they died and became supernovas. They traveled to Earth via comets billions of years ago, and formed organic compounds – the building blocks of all living things on our planet.
Technically, you’re 97% of that star stuff, which is pretty impressive, isn’t it?
So the next time you’re unhappy about your body, just think of how amazing you are to have come so far. Born of the stars. Grown from a primitive cell to a complex system.
By the way, in case you wondered, the uncoiled DNA from all the cells in your body would stretch from here to Pluto and back! Cool, right?