Change in body fat during a family-based treatment of obesity in children: the relative importance of energy intake and physical activity

Abstract

Objective: The aim of the current study was to examine to what extent changes in reported energy intake and physical activity predict changes in body fat during a family-based outpatient treatment of obesity in children.

Methods: Total body fat (DXA), reported energy intake (4-day diet record), and physical activity (accelerometer) was measured in 99 children (age 7-12 years, mean BMI SDS = 2.99) at baseline as well as after 6 months 2 years of treatment. Repeated measures (GLM), growth modeling, and structural equation modeling (SEM) were applied in the data analyses.

Results: There was significant decrease in body fat, reported energy intake, and physical activity at both follow-ups (p < 0.001) compared to baseline. Changes in reported energy intake from baseline to 6 months predicted a decrease in body fat from baseline to 6 months (β = 0.68, p < 0.001). In addition, changes in reported energy intake had a strong indirect effect on body fat at 2-year follow-up, mediated by changes in body fat from baseline to 6 months (indirect β = 0.50, p < 0.001). Changes in physical activity did not predict changes in body fat during treatment.

Conclusions: Changes in reported energy intake significantly affected body fat at 6 months and indirectly predicted the amount of body fat at 2-year follow-up. The indirect effect was mediated by a decrease in body fat obtained during the first phase of treatment.