Overweight Children at a Primary School in Hirosaki City: A Longitudinal, Individualized, Observational Study

The 2015 Annual report on growth velocity and physiologic status in schoolchildren revealed that the overweight incidence among fifth grade primary school in Aomori Prefecture was higher than the countrywide average. As a pilot study, overweight fifth grade (age, 10 years) children attending the attached primary school of Hirosaki University, Faculty of Education, were recruited in 2016, after which 6-year longitudinal change in physiological status between the first (age, 6 years) and sixth grades (age, 11 years) were evaluated using somatometric data obtained from the annual health checkup conducted each Spring. Of the 80 fifth graders recruited, none of whom had any underlying diseases affecting physiologic status, 6 (7.5%, 3 boys and 3 girls) were deemed overweight. Subsequently, 20 non-overweight children (10 boys and 10 girls) of the same grade were randomly selected for comparison. We used percent degree of overweight (%DO) for evaluating overweight instead of body mass index. Accordingly, compared with controls, overweight children already exhibited significantly greater weight and %DO at the first grade. Moreover, those who remained being overweight by the fourth grade showed %DO that tended to persist thereafter. Most overweight children exhibited increased annual velocity in %DO between the first and third grades. Overweight children showed varied fluctuations in %DO status throughout 6 years of primary school, whereas non-overweight children showed almost stable %DO within the normal range. The present study indicates the importance of early and sustained health education, particularly during the period before primary school entry until at least before fourth grade.