The government has been on a drive against official corruption and excess, which has seen gift-giving, banquets and the fiery liquor baijiu come under the spotlight. The aim is to calm public anger over extravagance by some officials.
"Authorities are not allowed to organise banquets or guzzle under the name of convening meetings and training," state news agency Xinhua said, citing a government circular.
Official canteens and cafeteria were asked to provide smaller portions of simple but healthy food and put up "save the food" slogans in prominent places.
China has been facing tight food supplies for a long time but food waste was rampant due to "ostentatious lifestyles and lack of supervision", the circular said.
President Xi Jinping earlier urged officials to "sweat" corruption out of the system.