Childhood obesity is one of the major public health problems in the twenty-first century. Up to 90% of all obesity cases in children and adolescents occur in a constitutional exogenous (simple) form. Treatment of obesity in its simple form in children is most appropriate to carry out on an outpatient basis. The main principle of prevention and treatment of overweight and obesity in children is the correction of nutrition and the development of healthy eating behavior. In order to improve the availability and quality of primary health care in the field of “dietetics”, a case-based approach to nutritional correction in overweight and obese children and adolescents has been developed. The proposed case-based approach has a modern scientific and methodological rationale, takes into account time norms for consulting patients during an outpatient appointment, is a plan of thematic consultations for the healthy diet development, ensures a gradual change in patient’s eating habits and individualization of the eating behavior correction, is aimed at the possibility of regular patient monitoring in the treatment process on an outpatient basis and promotes adherence to treatment. The development of the case-based approach is due to the high social significance of obesity, the tendency towards an increase in the number of overweight and obese children and adolescents in the Russian Federation and is aimed at implementing the main directions of the National Projects “Health” and “Demography”. © 2021, Dynasty Publishing House. All rights reserved.