[Refrigerator] Do refrigerator shelves bend when food is stored?

Do refrigerator shelves bend when food is stored?

Reason

As the width of refrigerator shelf is wide, it can bend due to the weight of stored food. 
It is a natural phenomenon.

How to check

More heavier the food is, the more the shelf is bent.

It is recommended to have the appropriate amount of food

on the shelf to use the product for a long time without failures.