To help people develop good habits, Clear Plate offers users credit points that can be exchanged to buy products

Liu Jinchen believes good behavior should be encouraged and awarded continuously so it becomes a good habit. The 24-year-old entrepreneur has succeeded in motivating millions of people to form the habit of clearing their plates as part of the nation's efforts to curb food waste, a long-lasting headache in China, through a more fun, relaxed and efficient way.

After finishing his dinner at the school canteen, Bi Haibao, a 26-year-old teacher from Qingdao Hengxing University in Shandong province, took a photo of his empty plate and uploaded it to a WeChat mini program called Clear Plate developed by Liu's company. After getting approval from the program's artificial intelligence judge, he was awarded virtual credit points that can be used to buy products or donate meals to children and older people in need.

Bi, who was one of the program's first users before it went viral on campus, led a student team to join a ranking competition for the "empty plate" campaign. "The result is remarkable, as many students mentioned their awareness of food saving had improved by the end of the semester," he said, adding that students first attracted by the AI program may gradually form good habits to save food.

China kicked off a nationwide campaign in August to curb food waste. Waste is found in restaurants, canteens, banquets and family parties, when the amount of food is large and likely to end up in a garbage can, damaging food security, worsening global warming and leading to soil contamination, experts said.

Liu, who founded Clear Plate in October 2018, said refusing food waste should be a lifestyle choice for everyone. "If everybody saves a grain of rice, it can feed 280,000 people for a year. There is an old saying in China, 'Take precautions before a rainy day'. Ensuring food security means both increasing food production and cutting food waste," he said. "It also means living a healthy and civilized lifestyle that benefits environmental protection."

Since its launch, Liu's AI-backed program has garnered about 4.2 million participants nationwide who have helped save 1,557 metric tons of food and have donated charity meals worth around 1 million yuan ($150,000), according to the company.

Clear Plate has cooperated with over 1,000 restaurants, as well as colleges, government organs and companies. The number of users is expected to grow from 20 to 50 million by the end of this year and expand to more countries in the future, he said. "The goal is to encourage everyone to take action, to refuse food waste and leverage a solution to safeguard global food security," Liu said.

The young entrepreneur was named one of the 17 Young Leaders for the Sustainable Development Goals recognized by the UN in September. He was chosen out of about 7,600 candidates worldwide and is the first Chinese person to receive the honor since its inception in 2016.

Then an undergraduate student in Tsinghua University, Liu was inspired by news about "leftover food parties" overseas. The idea of entrepreneurship was further cemented in 2017 when he visited a restaurant that would give repeat customers gifts if they cleared their plates six times.

"I think it's a great idea, but cards are easy to lose, so I thought of using internet tools like AI," he said.

Liu and his team spent half a year collecting more than 100,000 photos of empty plates in canteens and restaurants across the country to facilitate the image recognition capability of his AI program so that it would be able to correctly determine whether a plate is empty.

The project underwent two rounds of financing and raised a total of 8 million yuan by investors. Liu said as the number of users expands, more advertisers will be attracted, so the business can further develop itself.

"Nearly 100 percent of people will admit they have wasted food at some point, but this can be prevented by making small changes such as planning what to eat and how much to order in advance," he said.

"Promoting the idea by participating in games is more effective than putting up a poster, as users can get motivated physically and mentally by participating in credit point systems and charity events."

Zhang Dingyu, 25, who works at an environmental protection company in Beijing and promotes Clear Plate there, said about 2,500 young colleagues use the mini program and have uploaded photos of empty dishes more than 30,000 times.

The total amount of food saved is displayed on the mini program, "so they feel they have contributed and their sense of value grows, which helps them to make the practice a habit", she said.

Zhang said she learned to order a proper amount of food while dining out. Saving food also helps save costs in the industry chain of food production, processing and selling, she added.

Tang Ziye contributed to this story.