BEIJING - When Mr Ren Yushi eats out with his family, he makes it a point to order less, and to minimise waste, he takes home the leftovers.
But when it comes to entertaining guests and friends from out of town, the economics lecturer often orders more than they need. He does not want them to think him stingy.
"When you treat people (to a meal), you must be generous, even if it means you have to go home and eat pickled vegetables," said Mr Ren, 46.
"We have a tradition where we believe that being hospitable means having leftovers. If only empty plates remain, then it looks bad on you as a host."
This is what Beijing is up against with its latest "Clean Plate" campaign, launched last week by President Xi Jinping, who called on Chinese diners to stop wasting food.
Calling it "shocking and distressing", Mr Xi said in comments carried by the official People's Daily that habits of frugality must be cultivated.
To drive home his point, he quoted a Tang Dynasty poem: "Who knows that each grain in your bowl is the fruit of pain and toil."
Mr Xi's call to action reflects rising concerns over food security as Beijing grapples with a trade war, severe flooding and the Covid-19 pandemic that has strained global food production and supply chains, said observers.
Food waste is a big issue in China.
The average Chinese diner throws away 93g of food per meal when eating out, about 11.7 per cent of their meal, according to a 2018 study by a Chinese research institute.
The Chinese leader's comments have sparked a flurry of action over the past week from local governments, companies and restaurant associations.
Some like Shanxi province have directed officials to order "N-1" dishes at official meals, meaning one fewer dish than the total number of diners, while others have sent "food waste supervisors" to government-run canteens.
Video-sharing platforms Douyin and Kuaishou have also banned accounts that promote binge-eating, while the country's legislative body - the National People's Congress (NPC) - said it is considering enacting laws to curb food waste by diners.
This is not the first time Mr Xi has launched such a movement. In 2013, he started a similar campaign which mostly targeted extravagant feasts by officials.
But taking aim at the meal tables of 1.4 billion Chinese will be a challenge, say experts.
Professor Hu Xingdou, a political economist in Beijing, said the NPC's intent to enact laws on the issue is not a wise move, noting that it is "rare for a modern, developed country that interfere in people's lives in such a manner".
"Some people might find this quite laughable. If you make laws that you cannot implement, then people will stop respecting the law," he said.
Hong Kong-based political analyst Willy Lam noted that many Chinese might be looking to indulge in restaurants after months of living under the shadow of Covid-19.
"People will likely go through the motions and maybe order less food for awhile. In reality, the state cannot send police officers to all restaurants to monitor if patrons are being frugal enough," said Dr Lam.
But to Mr Ren and many other Chinese diners, the long-held traditions of hospitality will be the toughest thing to change.
"We Chinese are not very direct, so it's not nice to ask your guests how much food they can eat. These are all complexities.
"When treating guests, we like to be more generous and order more," he said.