Childhood obesity is one of the most serious public health problems. The prevalence of obesity among children is increasing and may negatively affect their immediate health, but it can also lead to obesity in adulthood. The aim of the study was to compare BMI cut-off points by examining three main international references: the World Health Organization (WHO), the International Task Force Obesity (IOTF) and the US Center for Disease Control and Prevention (CDC). Ultimately, the study group consisted of 18,144 children and adolescents aged 6.5–17.5 years. Body mass was measured on medical scales with an accuracy of ± 100 g and height measurement was taken using a height meter with an accuracy of ± 0.1 cm three times. Underweight, overweight and obesity were calculated according to WHO, IOTF and CDC BMI international references. There were differences in the incidence of underweight between the classifications: 16.8% according to IATF, 5.3% according to WHO and 9.9% according to CDC. There were also differences in the incidence of overweight and obesity between the classifications: 13% according to IOTF, 19.7% according to WHO and 14.1% according to CDC. In the CDC and WHO studies, a significantly higher prevalence of childhood obesity (4.0% and 4.7%, respectively) was observed compared with IOTF (2.1%). The prevalence of overweight and obesity in this study was higher among boys compared to girls. However, estimates of prevalence of overweight and obesity differ in methods and reference cut-off points. Higher prevalence was obtained in IOTF classification, followed by the WHO and CDC classification.

Overweight and obesity, as well as underweight in children and adolescents, pose a significant public health issue. This study aimed to investigate the secular trend of the incidence of underweight, overweight, and obesity in children from Ukraine in 2013/2014 and 2018/2019. The studies were conducted in randomly selected primary and secondary schools in Ukraine. In total, 13,447 children (6468 boys and 6979 girls) participated in the study in 2013/2014 and 18,144 children (8717 boys and 9427 girls) participated in 2018/2019. Measurements of body weight and height were performed in triplicate. Underweight, overweight, and obesity were diagnosed according to the standards of the World Health Organization (WHO). In the group of girls, a significant difference between 2013/2014 and 2018/2019 measurements was found only among 7-year-olds. The percentage of girls at this age exceeding the body mass index (BMI) norm was lower in the 2018/2019 study. In boys, a significant difference was also found in 7-year-olds, and, as in girls, a lower share of overweight and obesity was found in 2018/2019. But for the ages of 12, 13, and 15, the significant differences had a different character—more overweight or obese boys were found in the 2018/2019 study. The proportion of underweight children was similar for the majority of age groups in both genders and did not differ in a statistically significant way.

Актуальність. За останні десятиріччя стан здоров’я та фізичний розвиток дитячого населення України погіршуються. Серед факторів, що спричиняють зниження рівня дитячого здоров’я, чи не найважливіша роль відводиться навчальному навантаженню, стресогенна дія якого веде до розвитку дезадаптаційного синдрому з невротичними реакціями різного ступеня інтенсивності. Матеріали та методи. На основі даних анкетування школярів м. Львова у 2002 р. (20 000 школярів), 2013 р. (32 000 учнів) і 2017 р. (70 000 школярів) поданий порівняльний аналіз вікової частоти основних скарг і симптомів, медико-соціальних особливостей учнів 1–11-х класів. Результати. Стан здоров’я школярів останніми роками не має тенденції до покращання. Найбільш частими є скарги школярів на біль у животі, печію, нудоту, біль голови, зниження апетиту, симптоми вегетативної лабільності й астенічного синдрому, інші симптоми синдрому шкільної дезадаптації, що, ймовірно, пов’язано з високим рівнем шкільного навантаження, неадекватним харчуванням, дією стресогенних факторів на тлі значного зниження фізичної активності школярів. Сучасний раціон школярів є незбалансованим, він не забезпечує добового надходження всіх необхідних нутрієнтів, у тому числі вітамінів і мікроелементів. Висновки. Комплексний підхід до оцінки стану здоров’я школярів на основі об’єктивної інформації, впровадження нових оздоровчих технологій, об’єднання зусиль медичних працівників, педагогів і батьків може запобігти розвитку функціональних порушень і органічної патології в школярів, їх хронізації, зменшити симптоми шкільної дезадаптації, підвищити рівень здоров’я і їх здатність до навчання, а також запобігти розвитку захворювань у дорослому віці. При цьому дана технологія не вимагає значних фінансових інвестицій.

Introduction. The nutrition of primary school children does not always meet modern nutritional standards. The frequency of nutritional deficiencies, including calcium and vitamin D, among this age group remains unstudied. The aim of the study. To establish the characteristics of nutritional provision and the prevalence of nutrient deficiencies in the daily nutrition of primary school children, including calcium and vitamin D deficiencies and to propose methods of correction. Materials and methods. 5 consecutive stages of the study were conducted. At the first stage in 2019, the assessment of eating behavior in 190 children of grades 1-4 of two schools in the city of Lviv was conducted using a questionnaire. In the second stage, the features of the diet and ration and daily nutritional intake were determined using a special licensed program Dietplan 7 (UK). The analysis of daily nutrient intake was performed for 172 children. In the third stage, a study was conducted on the level of total, ionized calcium and 25-hydroxyvitamin D in the blood, and a study on the calcium content in the hair of 56 children with insufficient daily intake of calcium and / or vitamin D. In the fourth stage, 30 children with reduced levels of calcium in the hair were detected, differentiated correction measures were performed. To do this, the children were divided into two groups: the control group - 15 children whose deficiencies were corrected by diet modification, and the main group - 15 children - whose deficiencies were corrected by diet modification and the intake of calcium at a dose of 500.0 mg and vitamin D at a dose of 5.0 mg (200.0 IU) once a day for three months. In the fifth stage, to evaluate the effectiveness of treatment after three months of follow-up, all 30 children were re-analyzed for calcium content in the hair using atomic absorption spectrophotometry. Results. Appetite disturbance was observed in 28.9 % of schoolchildren, 17.4 % ate under duress, 14.3 % ate irregularly, 13.7% ate insufficient portions, 11.0 % were on different diets, many schoolchildren had eating disorders: ate before sleep (83.6 %), while watching TV (33.6 %). The diet was often unbalanced, children consumed insufficient fish (58.9 %), vegetables (43.2 %), dairy products (33.7 %), meat (26.8 %) Low calcium intake was observed in 50.6 % boys and 70.7 % of girls, vitamin D in 84.9 % of boys and 96.9 % of girls. Among children with a reduced daily intake of calcium and vitamin D, 42.9 % of children had a reduced level of total and / or ionized calcium, 48.2 % had a reduced level of vitamin D in the blood serum, and 53.6 % had a reduced calcium content in the hair. After 3 months of correction, we found that in the hair of children in the main group, who underwent dietary correction and were prescribed calcium and vitamin D, a significant increase in the average calcium content (up to 293.6 ± 80.6 mg/kg; p < 0.01) was observed, while in control group children who received only a modified diet, had only a tendency to increase the average amount of calcium in the hair (up to 185.14 ± 82.38 mg/kg; p > 0.05). Conclusions. For most primary school children, nutrition is unbalanced, which does not meet all the needs of a rapidly growing and intensively developing child's metabolism. A significant number of children have eating disorders: they do not eat regularly, do not eat enough food, eat food while watching TV, just before bed, do not have lunch at school, like fast food, 10% of students are on various diets. Almost a third of schoolchildren have a deficiency of daily intake of proteins, fats, carbohydrates and energy, and half of schoolchildren have a deficiency in the consumption of dietary fiber, polyunsaturated fatty acids and monounsaturated fatty acids. Most students have a daily deficiency of iodine, magnesium, selenium, iron and calcium, vitamin E, biotin, vitamin D, retinol, vitamin C, carotene, pantothenate. Among children with reduced daily intake of calcium and vitamin D in 42.9 % of children a reduced content of total and / or ionized calcium in the blood was found, and in 53.6 % of children in this group - in the hair. The use of a non-invasive method of studying the calcium content in the hair allows to determine the calcium deficiency in the child's body and control the process of its recovery. For children with insufficient daily intake of calcium and vitamin D, it is advisable to recommend a diet modification with increased consumption of milk, dairy products, yogurt and cheese, beans, spinach, broccoli, other leafy greens, wheat germ, nuts, sesame seeds, fish. To correct the existing calcium deficiency, it is advisable to use calcium supplements with vitamin D, combining this with a modification of the diet with an increase in food that contains the nutrients mentioned above. Keywords: schoolchildren, food deficiencies, calcium, vitamin D.

This study was conducted to determine the prevalence of calcium and vitamin D deficiency in school children aged 6 to 11 years in Lviv (Ukraine). The aim of this study was also to assess the effect of nutritional intervention and supplementation on serum calcium and vitamin D levels in children diagnosed with calcium deficiency. A 3 day diet was analyzed in 172 children. In 56 children with a deficiency of calcium and/or vitamin D, the level of total calcium, ionized calcium, and 25-hydroxyvitamin D in blood, as well as the calcium content in hair samples, was determined. Thirty children with confirmed calcium and/or vitamin D deficiency underwent a dietary intervention to increase calcium and vitamin D intake for 3 months. The study group (n = 15) was provided with a nutritional correction by modifying their diet with supplementation of calcium and vitamin D. The control group (n = 15) received only a diet modification. Decreased daily calcium intake was observed in 50.68% of boys and 70.71% of girls. A decreased level of daily vitamin D consumption was found in 84.93% of boys and 96.97% of girls. Among 56 children with insufficient daily consumption of calcium and/or vitamin D, 26.8% had reduced levels of total calcium in the blood, 16.1% had reduced levels of ionized calcium in the blood, and 48.2% had reduced levels of vitamin D. After 3 months of correction, normal calcium level was found in the hair of 10 students (66.7%) from the study group and in three subjects (20.0%) from the control group. Modification of the diet along with supplementation of calcium and vitamin D seems to be a more effective method for increasing the level of calcium among children aged 6 to 11 years.