The review presents current literature data on the prevalence of obesity and metabolic syndrome in children. According to the WHO’s prognosis, over 25% of children will be overweight and obese and about 7% of children will have metabolic syndrome in Europe by 2025. Long-lasting improper diet combined with reduced physical activity, with daily caloric food value exceeding vital energy requirements, is the main cause of excess body weight and obesity. It has been presented new, never-before-seen, properties of adipose tissue being the largest endocrine organ, which contains receptors for many hormones and produces its own peptide hormones-adipokines (leptin, adiponectin, resistin, tumor necrosis factor-alpha, etc.). It has been indicated that patients suffering from obesity and metabolic syndrome have impaired incretin effect (glucose-dependent insulin stimulation, decreased glucagon secretion) in response to the action of incretin hormones (glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide) caused by acquired receptor defects . It has been noted that differentiation of mesenchymal stem cells into two pools of cells (Myf5-positive and Myf5-negative) is subsequently completed with their transformation into white, brown and previously unknown beige adipose tissue. Metabolically healthy obesity, the phenotype of which is mainly due to the gene expression in the CNS, and Metabolically Unhealthy Obesity, the phenotype of which is due to the expression of peripheral tissue genes, are the most common phenotypes of polygenic obesity. It has been emphasized that Metabolically Unhealthy Obesity is considered by some authors to be the modernized name of the metabolic syndrome. The metabolic syndrome is known to be pathogenetically associated with obesity, hypertension, dyslipidemia, impaired glucose tolerance, and type 2 diabetes mellitus. It has been noted that until recently there were no uniform criteria for determining the metabolic syndrome in children. Nowadays, researchers keep to the criteria for Metabolically Unhealthy Оbesity in children, recommended by the American Association of Clinical Endocrinologists and the American College of Endocrinologists (AACE / ACE), 2014; and the European Society of Endocrinologists (ESE) and the Pediatric Endocrinology Society (PES), 2017. Early diagnosis and timely correction of obesity and metabolic syndrome is impossible without modern innovative medical technologies. The use of bioimpedancemetry for the diagnosis of total fat, visceral fat and metabolic age makes it possible to accurately diagnose visceral obesity, which is not recognized by body mass index, and timely administer a personalized lifestyle correction. Consequently, the widespread introduction of bioimpedancemetric analysis in paediatric practice will facilitate the early primary and secondary prophylaxis and development of comprehensive personalized treatment programs for obesity and metabolic syndrome in children.

Background. The problem of obesity in adolescents has gained its medical and social relevance since the incidence of the disease is steadily increasing. The purpose of the study is to improve the effectiveness of early diagnosis and prevention of obesity in adolescents. Materials and methods. To study the risk factors for obesity, a comparative assessment of lifestyle among adolescents aged 15–17 years with obesity, overweight and physiological body weight was conducted. In adolescents of the same age with comorbid obesity (basic group), overweight and physiological body weight (two comparison groups), the types of food behavior were determined using the Dutch eating behavior questionnaire (DEBQ). Bioelectrical indicators of bio-impedancemetric analysis were studied on a Tanita apparatus (Japan). The probability of differences in mean values was determined using Student’s t-test. Results. It was found that the frequency of imbalance of the food pyramid, movement disorders, sleep and rest, nervous tension, burdened heredity increased significantly among obese adolescents. Obesity was found to dominate by external type of eating behavior (57.2 %); at the excess weight — restrictive type (60 %); at physiological body weight — emotional type (40 %). Bio-impedancemetry showed that the reliable bioelectrical parameters of obesity were total fat (35.5 ± 4.5 % and 29 ± 2 % vs. 17.5 ± 2.5 %); visceral fat (17 ± 2 % and 12 ± 3 % vs. 8.5 ± 1.5 %); and metabolic age (33 ± 8 and 21.5 ± 1.5 years versus 16 ± 1 years). Conclusions. Risk factors for obesity include the imbalance of the food pyramid, movement disorders, sleep and rest, nervous tension, bad habits, burdened here­dity. The predominance of external type of eating behavior in obesity, restrictive — in overweight and emotional type in adolescents with physiological body weight should be taken into account when prescribing personalized lifestyle adjustments. The most informative bioelectrical parameters of bio-impedancemetry were total fat, visceral fat, and metabolic age. Bio-impedancemetry as a non-invasive predictive method of diagnosing obesity can be re­commended for widespread implementation in pediatric practice.