BACKGROUND: In the Russian Federation, the incidence of obesity continues to grow among the child population. Vegetative imbalance and chronic stress play an important role in the pathogenesis of obesity and related health disorders. Timely identification of disorders of psycho-vegetative disorders and their correction in overweight children require an integrated approach of medical and pedagogical workers.AIM: To reveal the features of the vegetative status, the level of school anxiety in students with an increased body mass index.MATERIALS AND METHODS: Children with different body mass index (BMI) underwent a comparative analysis of the mean values and structure of revealed violations of cardiointervalography (heart rate variability, HRV) parameters, laboratory test parameters (plasma antioxidant activity, plasma malondialdehyde, triglycerides, total cholesterol, cortisol, magnesium and serotonin) and test parameters School Anxiety Scale of Phillips.RESULTS: The prevalence of overweight was 23.1%. The observation group consisted of 47 schoolchildren with a body mass index (BMI) +1–2 SD the comparison group consisted of 156 children with a normal BMI at the age of 10–15 years. The groups were comparable in terms of sex and age (p=0.629–0.771). Analysis of background HVR indices revealed a decrease in the values of parameters characterizing the activity of the parasympathetic division of the autonomic nervous system (ANS), with a simultaneous increase in the indicators of the sympathetic division of the ANS in the observation group relative to the comparison group (p=0.001–0.023); similar results were obtained during the orthostatic test. The cumulative assessment of CIG indicates a lower activity of the parasympathetic division in the regulation of the state of rest and a greater activity of the sympathetic division of the ANS in response to a stress factor in children with an increased BMI value. The children of the observation group showed higher levels of malondialdehyde (p = 0.041), triglycerides (p<0.001) and cortisol (p=0.093) with lower values of magnesium and serotonin (p=0.074–0.076). The analysis of the level of school anxiety showed that in children of the observation group the average level and frequency of the prevalence of high values of the indicator of general anxiety are higher in 1.3 and 2.5 (p=0.005), fear of self-expression — in 1.3 and 1.8 (p=0.080–0.086), fear of the situation of knowledge testing — by 1.5 (р=0.002) and 2.1 (p<0.001), the level of general anxiety — by 1.2 (р=0.090) and 2.3 times (p=0.036) relative to the comparison group. In the course of the mathematical analysis, the results were obtained indicating the relationship between the parameters of the vegetative and psychological status.CONCLUSION: The problem of excess nutrition remains an urgent issue of modern health care. Excess body weight is accompanied by the activation of the sympathoadrenal system with an increase in the level of school anxiety and all together forms a vicious circle. Excessive nutrition in school-age children requires an integrated approach of specialists in the medical and psychological-pedagogical sphere.