Investigating eating architecture and the impact of the precision of recorded eating time: a cross-sectional study.

Background: The precision of recorded eating times directly affects the estimation of eating architecture i.e. size, timing, and frequency of eating. The impact of imprecise timing on estimates and associations of eating architecture with health remains unclear.

Objective: We compared eating architecture variables derived from precise versus broad timing methods and examined associations with anthropometric and diet-related outcomes.

Methods: Cross-sectional data came from 3-day diet diaries of 7-year-old children in the Avon Longitudinal Study of Parents and Children. We derived average size, timing, and frequency of eating, utilizing exact times (precise, n=4855) and mid-point meal slot times (broad, n=7285). Intraclass correlation coefficients (ICC) estimated agreement between methods. Bland-Altman analysis determined mean difference and limits of agreement (LOA). Correlations (95% confidence intervals) estimated associations between eating architecture variables and anthropometric or diet-related traits.

Results: Agreement varied from moderate to excellent for size (ICC 0.75), last or first time (ICC 0.80 or 0.58), and frequency (ICC 0.43) of Eating Occasions (EOs). Broad times underestimated eating frequency (2.2 times/day; LOA -1, 5) and overestimated size (83g; LOA -179, 13), last time (50min; LOA -142, 42), inter-meal intervals (68min; LOA -126, -11) and eating window (49min; LOA -161, 63). Directions of eating architecture intercorrelations were consistent regardless of time precision but varied in magnitude, e.g., larger EO size correlated with lower eating frequency but was stronger with precise time (r=-0.54 (95% CI -0.56, -0.52); r=-0.24 (-0.27, -0.22)). Correlations with anthropometric and diet outcomes were also directionally consistent.

Conclusions: Precise timing improves the estimation of eating architecture. Differences in estimation will affect descriptions of children's eating habits and possibly dietary guidance. However, consistent directional associations across timing methods, suggest that broad times could provide a pragmatic method for investigating eating architecture associations in large samples.