ИСТИНА

The living conditions that have changed in recent years lead to pronounced adaptive changes in the functional state of the human body. In particular, there are some reasons to state the “obesity epidemic” among children and adolescents. All our measurements were carried out at the beginning of spring, in schools of Moscow and the Moscow region. The number of research participants in 2003-2006 was 31 boys and 34 girls, in 2016-2019 - 42 boys and 56 girls. Standard methods were used to estimate body length and body mass, with subsequent calculation of body mass index (BMI). To assess the results in terms of “normal”, “overweight” and “obesity”, WHO tables were used as reference values (z-tables for boys and girls, with an accuracy of age characteristics up to 1 month). The boundary of the norm was considered the value of Me+1SD (percentile-84), the boundary of obesity - Me+2SD (percentile-97.5). We revealed that at both test points, the indicators of body mass and body mass index have not normal distribution due to a pronounced shift towards higher values (unlike body length, whose values have a normal distribution). In the first grades the average age in 2003 for boys was 7.8 year, for girls - 7.7, in 2016 - the same values. We found a statistically significant increase up to 2016 the body length, both in boys and girls whereas the averaged body mass and BMI were not statistically altered. However, the BMI's assessment of the “norm” did not correspond to 84% of children, as the WHO tables suggest, but 68% of boys and 77% of girls in 2003, 57% of boys and 68% of girls in 2016. The estimated “overweight” (expected 13.5%) corresponded to 16% of boys and 15% of girls in 2003 and 21% of boys and 18% of girls in 2016. The estimated “obesity” (expected 2.5%) corresponded to 16% of boys and 9% of girls in 2003 and 16% of boys and 14% of girls in 2016. By the end of the fourth-grade differences in average BMI did not reach the level of statistical significance. However, the boys showed a significant decrease in the share of “norm” (from 70% to 52%, p=0.034, exact Fisher method) due to an increase in the proportion of children with “overweight” (from 21% to 37%, p=0.062). In girls, we note the hidden (latent) shifts in the form of the redistribution of children within the “norm” range towards higher values. It is important that in girls the dynamics of BMI was related to the level of physical activity, and differences between classes with different levels of physical activity (only games, or the use of special exercises with heart rate of 160-170 beats/min) reached a level of statistical significance (p=0.023, ANOVA). The obtained data showed that the negative changes in medicine in terms of the physical development of children in the form of increasing BMI did not begin in the last 3 years. Their likely basis is a metabolic disorder, laid down in preschool age, before entering primary school.