Potato chips, instant noodles, drinks and biscuits topped the shopping list of bargaining hunters, the report said.

The data analysis agency iiMedia Research conducted a survey last year among Chinese consumers, according to which 80 percent of them had bought food approaching its expiry date.

Young people who like high-quality consumption but cannot afford it have become the main sales targets for expiring food, the agency says.

About 91 percent of internet users who responded to the survey said they believed that buying near-expired food helps protect the environment.

More than half said they had bought such goods because of the allure of big discounts, and more than 40 percent said they made the choice to help reduce food waste. More than 30 percent said they made such purchases to cut living expenses, iiMedia Research says.

On one hand, the purchase of near-expired food could help reduce the pressure of overstocked inventory on manufacturers, which reflects the rise of consumers' awareness of environmental protection, the agency says.

On the other hand, buying those cost-effective goods shows rational consumption and anti-consumerism among the modern Chinese shoppers, it says.

The market consultancy iResearch says the total output value of China's snack food industry exceeded 3 trillion yuan ($464 billion) in 2020.

Even if only 1 percent was regarded as overstock, the size of the market for near-expired food would exceed 30 billion yuan.

The market potential has drawn in capital investment and new players.

A total of 20 companies dealing in such foodstuffs were registered in the country in the first half of last year, an 82 percent increase from the same period of the previous year, iiMedia Research says.

By last year 94 businesses were dealing specifically in nearly expired food.

Such sellers can be found on e-commerce platforms including Taobao, Suning and JD.com, as well as social e-commerce channels such as WeChat Group and Mini Programs.

There are also specialty stores for these foods.

The franchise retailer HotMaxx offers snacks at bargain-basement prices, asking shoppers to pay 30 percent to 50 percent of the market price to enjoy big-brand food.

It has opened more than 200 outlets in China, including more than 60 now operating in Beijing, most sitting amid office buildings and business areas downtown, as shown by Dianping, the Chinese version of Yelp.