Introduction. The article examines the problem of creating healthy learning environments for children and adolescents. The purpose of this research is to identify the characteristics of functional state of schoolchildren’s adaptation system in conditions of limited use of mobile communication devices. Materials and Methods. Data for this study were collected using a hygiene experiment. The sample consisted of 355 schoolchildren. The observation group (n=155) included students separated from their mobile communication devices. The control group consisted of 180 students. The study involved evaluating the functional state of the adaptive capacity of compensatory adaptive mechanisms using generally accepted R. M. Baevsky’s method, modified for the purposes of the research. The identified indicators were subjected to statistical processing. The authors employed the following methods of theoretical research: comparison, formalization, generalization and system analysis. Results. The authors provide an international overview of interventions aimed at reducing mobile phone use in educational settings. The relationship between the state of schoolchildren’s adaptation mechanisms within all age groups and indicators of the cardiovascular system in conditions of separation from mobile communication devices was studied. The authors focus on the values of schoolchildren’s adaptive capacity in conditions of free use of mobile phones during the school day compared to the values obtained in conditions of smartphone separation. The study reveals the correlation between the activity and sensitivity of vegetative regulation of heart rate and gender and age characteristics. Conclusions. The research findings confirm the effectiveness of the restrictions imposed on the use of personal mobile communication devices at comprehensive schools. The authors conclude that limited use of mobile communication devices prevents reducing adaptive capacity of the child's body, therefore it reduces the risk of fatigue and pathological changes.

Introduction. This article presents the results of a large-scale research on monitoring the nutrition of students in educational institutions. Nutrition is one of the leading factors determining the health and harmony in the processes of growth and development of the child population. One of the most common consequences of unhealthy eating behavior is overweight and obesity. The study and early detection of risk factors is necessary for the prevention of overweight and obesity, which are an acute problem of modern science and education. The purpose of the study is to assess risk factors for overweight and obesity in schoolchildren in order to develop effective programs for the prevention of childhood obesity and nutritional diseases. Materials and Methods. The research data were collected and processed via the following methods: a questionnaire, analytical and statistical methods using parametric and non-parametric methods of statistics and t-test (in the case of normal distribution of data) and Fisher (U). Differences were considered statistically significant at p<0.05. The STATISTICA-10.0 package and Microsoft Excel were used. Results. As part of the global monitoring of schoolchildren’s nutrition (the survey covered 43.9 thousand schoolchildren from 49 regions of the Russian Federation), the following key risk factors for nutrition-related health disorders in schoolchildren were identified: a violation of the structure of nutrition, unhealthy eating behavior and eating habits, violations in the organization of nutrition in educational institutions and at home. Statistically significant correlation coefficients were found between indicators of normal body weight and family income, between overweight and unhealthy eating habits, and eating behavior, the prevalence of diseases of the digestive system. Forecast indicators of a decrease in the prevalence of obesity with a decrease in the proportion of children with unhealthy eating habits have been established. Conclusions. The results of the study characterize the key risk factors for the development of overweight and obesity in children associated with nutrition. In the future, the results obtained can be used to predict the effectiveness of implemented preventive measures at the level of individual educational institutions and territories of the Russian Federation.

Introduction. The authors present the results of a study devoted to the issue of forming the basics of healthy eating for schoolchildren in the Russian Federation, which is the main goal of ‘Demography’ National project, aimed at monitoring schoolchildren’s nutrition and health. An important part of solving this problem is raising schoolchildren’s awareness of and their commitment to the principles of healthy nutrition, as factors reducing the risk of overweight and obesity, which are predictors of alimentary-related diseases. The aim of the research is to examine awareness of and adherence to the principles of healthy eating among schoolchildren with different body mass index in the Russian Federation in order to develop an integrated approach to activities and interventions aimed at developing healthy eating habits and eating behavior according the principles of healthy eating. Materials and Methods. The work used sociological (questionnaires), analytical and statistical research methods. The study was conducted in 66 constituent entities (federal subjects) of the Russian Federation among students in educational institutions and their parents (legal representatives) and heads of educational institutions in accordance with MR 2.3.0167-20, approved by the Chief State Sanitary Doctor of the Russian Federation A.Yu. Popova, March, 20, 2020). The study was conducted in the form of a sociological survey. The assessment of anthropometric indicators given by the respondents during the survey was carried out using the WHO methodology (2007). Statistical processing was conducted using the STATISTICA-10.0 system and Microsoft Excel using descriptive methods of statistics and t-test (in case of normal data distribution) and Fisher (U). Differences were considered statistically significant at p <0.05. Results. When analyzing the data of the survey, the authors found that the majority of schoolchildren and their parents (legal representatives) participating in the study are familiar with the principles of healthy eating, while only about a quarter of them follow these principles. Peculiarities were revealed in indicators of respondents' adherence to the rules of healthy eating depending on nutritional status, indicating a greater proportion of children with overweight and obesity among those who are unfamiliar with the principles of healthy eating. There were no significant differences in age and place of residence. However, all groups demonstrated low consumption of milk and dairy as well as wholemeal bread, which are characterized by large amounts of useful macro- and micronutrients. Priority sources of information about the principles of healthy eating have been established. They include healthcare workers, the Internet and television, respectively. It was revealed that in most educational institutions sanitary and educational work is carried out, aimed at developing skills and the need for a healthy diet. The largest number of children participating in the implementation of educational programs is primary school students with a low proportion of middle and senior school students. Conclusions. The study concludes that implementation of programs aimed at increasing schoolchildren's knowledge about the rules of healthy eating plays a significant role in ensuring healthy nutrition of schoolchildren, which contributes to the formation of adequate adaptive capabilities of the child's body and reducing the risk of alimentary-related pathology. The authors emphasize that when developing and implementing the programs it is necessary to pay attention to the identified features in the awareness of and commitment to the principles of healthy eating among overweight and obese schoolchildren and to increase the participation of middle and senior schoolchildren. The development of a family-associated approach to solving the problem is considered to be promising.

Summary. Introduction: At present, training of highly qualified military personnel including cadet corps students acquires special importance. Educational programs in cadet corps provide for high daily physical activity of students. At the same time, daily food rationing regulated by current sanitary norms and rules does not comply with higher energy expenditures of such students. The purpose of our study was to substantiate a healthy diet of students of boarding schools taking into account their total daily energy expenditures, calorie needs and requirements for micro- and macronutrients ensuring a high level of functional state of the body, high mental and physical performance. Materials and methods: We studied indicators of health status and physical development of cadets based on the results of medical examinations, results of assessing daily physical activity, and school meals. Daily timekeeping and pulse measurements were used to estimate daily energy expenditures and activity levels. Evaluation of nutrition was based on the analysis of a cyclic menu, process charts, menu layouts, and catering hours. Conclusions: The regulated daily norms of food products adopted in cadet corps subordinate to the Ministry of Education of the Russian Federation are significantly lower than actual energy expenditures of their students. This reality determines the necessity of revising food rationing. Draft guidelines for hygienic justification of the recommended diet for students with a higher level of physical activity have been developed. The proposals for improvement of boarding school meals were included in the appropriate sanitary rules and regulations within the framework of the regulatory guillotine.

Obesity is the most common reason for the insulin resistance (IR) though obesity in children is not always associated with IR. The markers based on fasting glucose and/or insulin levels and alternative parameters with conventional lipid-based indexes are used in assessing the IR in clinical practice. The purpose of the research was to assess the relationship between alternative IR surrogate biomarkers as follows: triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C), TG/HDL-C ratio; single-point insulin sensitivity estimator (SPISE) index; triglyceride-glucose index (TyG), with generally accepted indices based on the insulin/glucose ratios, such as HOMA-IR, QUICKI, Caro, in a cohort of obese children and adolescents. Materials and methods used: a single-stage multicenter comparative study was conducted involving 127 patients aged 6 to 17 y/o with simple obesity of varying degrees. The following indices were calculated: HOMA-IR = fasting insulin (mU/ml) x fasting plasma glucose (FPG) (mmol/L) / 22.5; QUICKI = 1/Log (Fasting Insulin, µU/ml) + Log (Fasting Glucose, mg/dl); Caro = fasting plasma glucose (mmol/l) / fasting insulin (μU/ml); TG/HDL-C = TG (mmol/L) / HDL-C (mmol/L); triglyceride-glucose index TyG = Ln [fasting TG (mg/dl) x fasting plasma glucose (mg/dl)/2], where Ln is the logarithm; SPISE = 600 × HDL-C0.185/(TG0.2 x BMI1.338). Results: 75 (59%) boys and 52 (41%) girls were included in the study; the median age was 12.9 [10.4; 14.9] y/o. Pre-pubertal development was recorded in 25 (19.7%), pubertal - in 102 (80.3%). The prevalence of impaired glucose tolerance (IGT) was 5.5%. In children with IGT, the SPISE index was lower than in children with normal glucose tolerance (3.69 [3.49; 4.37] vs. 4.8 [3.99; 5.55], p=0.021) with no statistically significant differences between these groups in other markers. In the IGT subgroup, a high negative correlation was found between SDS BMI and SPISE (R=-0.97). In the general SDS group, BMI correlated with insulin (R=+0.24), TG (R=+0.2), HOMA (R=+0.24), Caro (R=-0.26), TG/HDL-C (R=+0.28) and SPISE (R=-0.65). The SPISE index was lower in girls than in boys (4.94 [3.63; 5.73] vs. 4.07 [3.59; 5.16], p = 0.045). No statistically significant differences were recorded for other gender-related markers. A negative correlation was also found between the obesity degree and SPISE in the subgroups of girls (R=-0.49) and boys (R=-0.70) as well as among pre-pubertal children of both genders (R=-0.61). The maximum correlation between SDS BMI and SPISE was recorded in the subgroup of teenagers of both genders (R=-0.88). In the general group, TyG was weakly correlated with HOMA-IR (R=+0.26) and QUICKI (R=-0.24), while SPISE showed a weak association with all studied insulin indices; no statistically significant correlation between insulin indices and TG/HDL-C was found. In the subgroup of girls, no significant relationships between the evaluated markers were found, in the subgroup of boys, TyG weakly correlated with HOMA-IR (R=+0.29) and QUICKI (R=-0.32). Stronger correlations were recorded in boys between SPISE and all studied insulin indices. In the subgroup of prepubertal patients, a correlation was found between TyG and QUICKI (R=-0.44), SPISE and Caro (R=+0.56), SPISE and HOMA-IR (R=-0.50). The TG/HDL-C ratio did not statistically significantly correlate with traditional IR markers. TyG showed weak correlations with HOMA-IR and QUICKI in the general group and the boys’ subgroup. In the prepubertal period, TyG only weakly correlated with QUICKI and did not show strong associations with insulin-based indices in pubertal children. The SPISE index showed correlations with insulin markers both in the main group and in individual subgroups. Conclusion: the SPISE index can be considered as a relatively simple and accessible method for assessing IR in obese children and adolescents.