Gender and age

The researchers identified a number of factors, including age and gender, that significantly affect food wastage.

"Men generally waste more food than women, while people aged 50 or older waste significantly less than people younger than them," Cheng, the professor, said.

He added that men generally attend more business-related dinners than women, and "men generally order more, consume more and waste more".

The researchers discovered that food wastage rises in tandem with the number of people attending a dinner, and the volume of wastage peaks when nine people are taking part.

"That is because a banquet becomes more formal as the number of people rises. The less the banquet is about eating, the more waste there may be," he said.

The research also showed that the level of education plays an important part in with food wastage in restaurants; better-educated people waste less food than those with a lower level of academic achievement.

Cheng said the less-educated the consumer, the more eager they are to flaunt their wealth at business banquets, resulting in greater wastage of food.

Wang Cunhua, a 23-year-old waitress at a restaurant in Beijing's Chaoyang district, said wasteful behavior is more prevalent a mong men and younger customers.

"Compared with females, male customers pay more attention to displaying their generosity. They also drink more and the more they drink, the more wastage there will be because they ignore the food," she said.

However, she added the most significant factor is the widespread fear of "losing face" when not enough food is provided for guests, which means the host generally orders far more food than is necessary. "The cost of 'face' is unbelievably high at dinner parties," she said.

The researchers calculated that this could result in 20 grams of food being wasted per person per meal. Another reason is that guests consume far more than usual at dinner parties to indicate that they have enjoyed the food, which could result in 80 grams of food being wasted per person per meal, according to the research.