Incidence of the Christmas holiday period on the weight condition of primary-school students

Introduction: The aim of this study was to analyze changes in body mass index (BMI) of primary-school students and the differences between children with normal-weight, overweight and obesity after the Christmas holiday period. Material and methods: Longitudinal and prospective descriptive study was performed. A total of 156 students of the public school Doctor Fleming from Jódar, Jaén (Spain) participated in this study, aged 8 to 12 years: 119 with normal-weight, 18 with overweight and 19 with obesity. Measurements of height, weight, and BMI were taken at three moments: in the school period prior to the Christmas holiday, after a non-school period (Christmas holiday) and 20 days after the Christmas holiday, with an interval time between measurements of 20 days. Results: The data (mean [standard deviation]) showed an increase in the BMI after the Christmas holiday period in all groups: normal-weight: 0.09 (0.43) kg/m2; overweight: 0.29 (0.46) kg/m2; and obesity: 0.50 (0.70) kg/m2 with significant differences between normal-weight and obesity (p = 0.007). Returning to the school period, children with normal-weight were approximated to near values to the first measurement with significant differences (p