Where does
your lunch go?

The full narration of the video.

That bite of lunch you had today: where is it right now? It didn't just drop into your tummy and stop. It's travelling a very, very long road inside you. That road works like a factory line. At every stop, someone does one job.

First stop: your mouth. Teeth crush the food, and your tongue mixes it. Spit is working too. It snips the rice into smaller bits and makes a little sweetness. When you swallow, the food enters a soft tube called the food pipe. But it doesn't just fall down.

The tube squeezes, ring after ring, like squeezing toothpaste, and pushes the food to the bottom in a few seconds. That's why astronauts floating in space can still swallow their dinner. At the bottom of the tube is your stomach. It's like a mixer: it squishes and squeezes, and pours on sour stomach juice.

After a few hours of mixing, the food turns into a runny mush. The mush flows on into the small intestine. Take a guess: if you stretched yours out straight, how long would it be? Several times taller than you! Even a newborn baby's small intestine is over two meters long.

Inside, it isn't smooth. It's covered in soft little fingers, like a fluffy towel. As the mush flows past, the fingers soak up the good stuff, send it into your blood, and off it goes all over your body. The energy you use to grow and run and jump comes mostly from right here.

Whatever is left gets pushed into the large intestine. It slowly pulls the water back into your body. What's left gets drier and firmer, and becomes poop. The large intestine is also home to lots of tiny, invisible germs. They're the reason poop turns brown.

The whole trip takes about a day and a half. Less than a day, or three or four days, are both common. This factory line has a real name: the digestive tract. It's one long, connected tube, from your mouth all the way to your bottom. A factory puts parts together. The digestive tract does the opposite: it breaks a big bite into pieces too small to see, so your body can soak them up.

At dinner tonight, take one bite of plain rice and keep chewing. Don't swallow yet. How many chews until you taste something sweet?