Children should understand from a young age the principle of 'who knows the food on the plate'.
Tips
history
From Li Shen's (李绅) Tang poem 《悯农》 (Sympathy for the Farmer) II. Couplet: 谁知盘中餐，粒粒皆辛苦 — 'Who knows the food on the plate? — every single grain is toil.' The first of the two 《悯农》 poems ends 四海无闲田，农夫犹饿死 ('though all the land is tilled, farmers still starve to death'). Taught to almost every Chinese primary-school child; quoted at nearly every 'clean your plate' campaign.
usage
Paired couplet — always quoted with its mate 粒粒皆辛苦. Staple of food-waste campaigns, restaurant wall slogans, school cafeterias, and rural-appreciation writing.
