Increase in prevalence of adiposity between the ages of 7 and 11 years reflects lower remission rates during this period

Abstract

What is already known about this subject? A considerable increase in the prevalence of overweight during the primary school years (7-11 years) has been reported. What this study adds? This reflects lower remission rates of excess body fat (i.e. the proportion of shifts from excess to normal body fat) between the ages of 7 and 11 years as compared with nearly balanced incidence and remission rates of excess body fat between the ages of 3 and 7 years.

Objective: This study aimed to compare the age-specific balance between incidence and remission of excess body fat between the ages of 3-7 and 7-11 years using the data from a longitudinal study.

Design: Longitudinal analysis based on the data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study, an ongoing, open cohort study in healthy children, conducted in Dortmund, Germany. Excess body fat was defined by the sum of triceps and subscapular skin-fold measurements above the 90th reference percentile of the new German standard; overweight was defined using different national and international standards. The main outcome parameters were incidence and remission rates of excess body fat (n = 496) and overweight (n = 518) between the ages of 3 and 7 years and between the ages of 7 and 11 years.

Results: The incidence rates of excess skin-fold thickness between the ages of 3 and 7 years (4.2 [2.4, 6.2]%) and between the ages of 7 and 11 years (4.3 [2.6, 6.2]%) were almost identical. By contrast, remission rates were significantly lower during the age period of 7-11 years (primary school age) than during the age period of 3-7 years (pre-school age): 37.5 (21.9, 53.1%) compared with 72.3 (59.6, 85.1%).

Conclusions: These data point to the low remission of excess body fat as an important driving force for the increasing prevalence of excess body fat in children between the ages of 7 and 11 years. Public health initiatives in children should encompass both primary prevention and interventions targeted at children already overweight at school entry.