Daily Eating Window and Obesity Markers in a Sample of Schoolchildren from Vienna: Insights from the EDDY Study

Abstract

Background/Objectives: The eating window concept has been understudied in children, with no reports from Austria. This study explored meal timing and its association with obesity-related variables in a sample of Viennese schoolchildren. The effect of a healthy intervention on obesity variables according to the daily eating window was assessed. Methods: The EDDY study included 138 third-grade students from three Vienna schools. Baseline meal timing was assessed using self-administered questionnaires, and the daily eating window—the time between the first and last meal—was calculated and categorized into tertiles. Anthropometric and body fat measurements were taken at baseline and after 21 months. Baseline outcomes were compared between children with long (LEW; 3rd tertile) and short (SEW; 1st tertile) eating windows using adjusted linear regression analysis. Longitudinal changes were analyzed using mixed models for repeated measures. Results: The median age was 7.9 years, and 26.8% were classified with overweight/obesity. The children’s eating window spanned 11:40 h, from 7:00 to 19:00. More than half (52.2%) reported fasting 1–2 h before bed. Children had four daily meals; 16.4% skipped breakfast, while 51.5% ate it regularly. Meal timing variables did not differ by weight status. Children with a LEW (≥12:05 h) had lower BMI-SDS (−0.66) and fat mass index (−1.06) than those with a SEW (≤11:05 h). No longitudinal changes in BMI-SDS, fat mass index, or waist-to-height ratio were observed across eating window tertiles following the intervention. Conclusions: In a non-representative sample of Viennese children, the eating window ranged from 9:30 to 13:30 h, similar to Austrian adults but differing from other Western European countries.