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.