There is a difference between the kind of things that you take in when you breathe and the kind of things you take in when you eat or drink.

Food and drink are solids and liquids; and the body is a great sponge of one soaked full of the other, so that large amounts of food and water can be stored up in the body.

But what you take in when you breathe is, of course, air--which is neither a solid nor a liquid, but a gas, very light and bulky.

Of gases the body can soak up and hold only a very small amount; so its storage supply of them will be used up completely in about three minutes, and then it dies if it cannot get more air.
Why our Bodies Need Air-Oxidation.

The body is made up of millions of tiny living animals called cells, which eat the food that is brought to them from the blood and pour their waste and dirt back again into the same current.