1, malnutrition and obesity. Malnutrition and obesity coexist among primary and secondary school students, and experts call it the “bimodal phenomenon”. At the national level, malnutrition among children is always relatively concentrated in the west, but in Beijing, among primary and secondary school students aged 6-18, malnourished children also account for 6-7%, the reasons for which are partial eating, picky eating, excessive snacking, excessive dieting for the pursuit of model figure, etc.. Compared with malnutrition, a more serious problem is obesity. In the past two years, the growth rate of obese children is alarming, and about 15% of primary and secondary school students in Beijing are obese, a figure that has doubled compared to 10 years ago. Obesity has an impact on the physical and mental development of adolescents, and childhood obesity can lead to adult obesity, which in turn can lead to hypertension, coronary heart disease, diabetes and other diseases. These diseases have now shown a trend of low age. In 1999, the prevalence of myopia among primary and secondary school students in China ranked second in the world, second only to Japan. In urban areas, the prevalence of myopia remains high and continues to grow, while in rural areas, it has increased significantly. The heavy burden of schoolwork and excessive eye time are the main causes of myopia among teenagers. And the onset of myopia has advanced. In the past, the focus of myopia prevention was after the age of 9, but now parents and schools should start to prevent myopia in kindergarten and as soon as children enter elementary school. At the same time, after reducing the burden of school work, parents should pay attention to let their children not to use their eyes excessively at home, watching TV, playing video games, watching CDs for too long will cause damage to the eyes. 3.Dental caries. The incidence of tooth decay among primary and secondary school students in China is not high compared with the world level, but the problem of not repairing tooth decay in time is prominent. Some children lose their permanent teeth at a young age. The decayed teeth should be repaired in time, even the baby teeth should be repaired, because if the baby teeth are lost too much, it will affect the arrangement of the permanent teeth after they grow out. 4.Anemia. The problem of anemia is always similar to malnutrition in children in big cities. This anemia is not caused by lack of food, but is related to dietary habits and lack of nutritional knowledge. For example, some parents may not know that copying vegetables with an iron pot can invariably add a lot of iron to the child. Another example is that drinking orange juice and eating tomatoes before eating can promote the absorption of iron; while drinking tea after meals is not conducive to the absorption of iron. In addition, although milk and eggs contain iron, it is difficult to absorb, while the iron in lean meat and pork liver is easily absorbed. Knowing this knowledge, correcting anemia is easy to do. 5. Mental health problems. Currently among primary and secondary school students, excessive shyness, timidity, tendency to violence, anxiety, depression and other psychological problems are prominent, especially when faced with the pressure of higher education, employment and early love. Experts expect that the occurrence of psychological problems among primary and secondary school students will also be on the rise in the coming period.