China plans to introduce a new grading system for its restaurants, awarding a smiley face to establishments that score high grades for hygiene, and an unhappy face for those with a food safety problem, the official Xinhua news agency reported Sunday.

Restaurants in China are famous for producing mountains of delicious food, but a look behind the scenes at the state of the kitchens can make even the hungriest diners lose their appetite.

China's State Food and Drug Administration is drafting new rules to force restaurants to display simple stickers to inform customers how safe it is to eat there.

A smiley face will represent "excellent," a straight face means "good," and an unhappy face indicated average.

Inspectors will grade restaurants after inspecting food materials, sanitation and hygiene, the report said.