In the aspect of daily diet, generally speaking, the left behind children do not have big problems, but because the left behind children are young, they will not be matched and selected in diet, which often causes some problems of unbalanced nutrition or unhealthy diet, especially when both parents of the left behind children go out, this situation is more serious. The age of left behind children is the peak and critical period of human growth. The perfection and growth of human body structure such as height are mostly completed in this period. Reasonable diet and balanced influence are the key factors to ensure the healthy growth of children. If the diet is not reasonable, or the nutrition imbalance often causes such problems, it will even affect the life of children in adulthood. Most of the survey found that many guardians often provide simple but nutritious snacks for the left behind children, such as instant noodles, biscuits and other foods, for convenience. Some guardians, due to the lack of common sense of food safety and greed for cheap food, even buy some poor quality food. Long-term use of these food will seriously affect the growth of children, and even endanger their lives and health.