Food behavior was studied in schoolchildren of the same age in the GDR (1602) and in the Lithuanian SSR (720 schoolchildren). The examinee represented schoolchildren from towns, regional centres and rural areas. Food behavior of schoolchildren, aged 11-13 years, in the GDR and the Lithuanian SSR is practically similar, but it has been noted that more children in the GDR receive a second breakfast, while in the Lithuanian SSR more children receive afternoon snacks. The schoolchildren should be taught the principles of the rational nutrition during their studies. Active sanitary propaganda is necessary for learning the principles of sound way of life including the principles of rational nutrition.