What if I told you the whole world was one gigantic machine running on electricity? No, there are (probably) no aliens involved and yes, if we switched off the power everything would go kaboom.
It’s actually not that far from how things work. Plants, animals, humans all need energy to exist (imagine hearts beating, bodies breathing, plants growing), and even more energy to move or keep warm or play.
Everything that is alive on earth uses the same energy, and to be able to measure it smart people decided to divide it up into joules. Just as we use hours to measure time and degrees to measure temperature, we measure energy in joules (read: jools). You might not actually have heard of joules before, but you probably have heard the word calories – which is just another way to measure energy, and some people find that one easier to use.
One calorie is the energy needed to warm 1 gram of water by 1 degree Celsius.
Now imagine the energy your entire body needs to keep you warm. Then add the energy your hearts need to beat. Then add the energy you need to breathe – shoulders going up and down, chest going in and out. Then add the energy your hands need to hold your phone steady (or your tablet or whatever you use to read). Then add the energy needed for your brain to understand the words… Do you see how your body needs a lot of energy to function? And if you have walked today, or stood up, or even just moved, you used up even more. Roughly speaking, your body will use up about 2 000 000 cal to get you through one day! (Just on the side, if we are talking about more than 1000 calories and the numbers get too big, we usually change to kilo calories, with one kilo calorie being the same as 1000 calories).
Now how does your body get all that energy it needs everyday? Because if it didn’t, you would not be alive.
You guessed it.
Food.
Food is energy. Energy with a flavour. Food is flavoured batteries. Remember that next time you eat a cookie.
Yum!
Food is what we call energy our body can use.
Your body can drain almost all the energy from a cookie after you eat it. But your body cannot drain any energy from metal, so metal is not food.
In order for you to be alive and healthy, you have to give your body enough energy, every day, to do all of its jobs.
That is what I call your Food Wallet. And we will see what it is and how you use it, much like your money wallet, to buy things you either need or want.
But first, there is another reason why we eat, which we will look at next time.
Everything is energy.
– Albert Einstein