A randomized controlled trial on a multicomponent intervention for overweight school-aged children - Copenhagen, Denmark

Abstract

Background: Obesity amongst children is a growing problem worldwide. In contrast to adults, little is known on the effects of controlled weight loss on components of the metabolic syndrome in children. The primary aim of the study was to evaluate the effects of a 20-week exercise and diet guidance intervention on body mass index (BMI) in a group of overweight children. Our hypothesis was an observed reduction in BMI and secondarily in body fat content, insulin insensitivity, and other components of the metabolic syndrome in the intervention group.

Methods: School children from Copenhagen were randomly allocated to an intervention group (n = 19) or a control group (n = 19). Anthropometric assessment, whole body dual-energy X-ray absorptiometry scan, two hours oral glucose tolerance test, steps measured by pedometer, and fitness tests were measured at baseline and at 20 weeks.

Results: Thirty-seven children (30 girls) participated at baseline, aged 8.7 ± 0.9 years with a BMI of 21.8 ± 3.7 kg/m2 (mean ± SD), and 36 children completed the study. The intervention group decreased their BMI (the intervention effect is the difference in change between the groups adjusted for the respective baseline values (DELTA) = -2.0 kg/m2, 95% CI: -2.5; -1.5, P <0.001), total body mass (DELTA = -4.0 kg, 95% CI: -4.9; -3.0, P <0.001), and fat mass (DELTA = -3.3 kg, 95% CI: -4.2; -2.7, P <0.001) compared to the control group after the intervention. The intervention group displayed decreased waist, hip and waist-to-height ratio (WHtR) (all three variables; P <0.001), area under curve for plasma insulin (P <0.05), and increased mean and minimum steps/day (P <0.05 and P <0.01, respectively).

Conclusions: The multicomponent intervention had significant favorable effects on BMI, weight, WHtR, mean and minimum steps/day, and fat mass. In addition, similar beneficial metabolic effects were found in the children as shown in adults, e.g. increase in peripheral insulin sensitivity.

Trial registration: Clinicaltrials.gov Identifier number NCT01660789.

Figure 1

Design of the randomized controlled trial. CONSORT 2010 Flow Diagram [34] showing the number of children invited, enrolled, allocated, at Follow-Up, and in the analyses. *Children (age 7–10 years) at inclusion time in Høje Taastrup Municipality who were identified as overweight or obese by the ‘SundSkoleNettet’/‘The Healthy Schools Network’. **Children (age 7–10 years) at inclusion time who participated in the early evening information meetings.

Figure 2

The glucose metabolism measured by oral glucose tolerance test. The area under curve is shown as bar graphs, while the response over time is shown as curves for plasma insulin (A) and glucose (B), respectively. P values are representing the intervention effects (the difference in change between the groups) adjusted for the respective baseline values (95% confidence intervals as error bars on bar graphs and Standard Error of the Mean as error bars on curves). ★, P <0.05; ns, not significant.

Figure 3

Physical activity measured by pedometer. Weighted mean steps per day (A) and mean minimum steps registered on the least active single day (B) registered by Pedometer. P values are representing the intervention effects (the difference in change between the groups) adjusted for the respective baseline values (95% Confidence intervals as error bars). ★, P <0.05; ★★, P <0.01.