CHANGSHA - Preschooler Shi Bing in central China, wants to grow up faster so he can go to elementary school where he will get a free school lunch instead of going home for the same cold steamed buns and pickles every day.

Shi has another 12 classmates in a mountainous area of Guzhang County, Hunan Province, who all share similar lunchtime conundrums simply because their families cannot afford the 4 yuan (less than one U.S. dollar) meal fee. Most of them just buy cheap snacks full of additives but with very little nutritional value. A news clip of the poor kids and their poor lunches aired on China's state broadcaster this week captured the public's imagination.

China gives subsidized school lunches to underprivileged students in compulsory education, but that compulsory education only begins at age six. About 23 million students in 100,000 rural schools are covered by the program, and there are also free daily nutritional supplements for hundreds of thousands of poor rural infants under 2 years old. For those between 3 to 5 years, the cupboard is bare.

Malnutrition threatens a generation of rural Chinese. Hidden hunger -- lack of micronutrients such as vitamins and minerals -- is not easily spotted in the early stages. Hidden hunger has led to an obvious differential in height and weight between children of the same ages in rural and urban areas.

A 2015 survey by the Chinese Nutrition Society found the malnutrition rate among under-sixes in China at 8.1 percent, and anemia at 11.6 percent overall, but the rate for rural children was two to three times that of their cousins in the cities. Stunted growth among rural children under 6 years old was also two to three times more prevalent in the countryside.

"A child's intellectual development is half complete at four years old," said Zhang Zheng from Amway Charity Foundation, "and development of cerebral cells is complete by the age of six."

Zhang said poor nutrition during infancy leads to irreversible harm to children's intelligence and physical strength. The foundation has been giving chewable supplements to children under five in poor villages in eight provinces since May.

In Hunan's Xiangxi Autonomous Prefecture, preschoolers from low income families receive 1,000 yuan each year. When they move on to elementary school, that amount rises to 1500 yuan.

The China Development Research Foundation, a non-profit organization under the Development Research Center of the State Council, has opened "village kindergartens" in seven provinces, including Guzhang where Shi Bing lives, and offers one yuan of nutritional subsidy for each preschooler each day.

"There is only so much that local governments and NGOs can do. We hope preschoolers, especially those in poor areas, will soon be included in the national nutrition improvement plan," said Bao Taiyang, Xiangxi Prefecture's head of education and sports.