Your waist is the part of your body where your belly button is. It's like a circle around your body, right in the middle. It's where your pants sit when you wear them.
When you grow, your waist gets bigger too. Just like a balloon gets bigger when you blow it up, your waist gets bigger too. That's why sometimes your pants might feel too tight or too big.
It's important to take care of your waist by eating healthy foods and being active. That way, your waist can stay healthy too!