The Association Between Midpregnancy Food Intake Timing Patterns and Gestational Weight Gain.

Background: This article aims to characterize midpregnancy food timing profiles and examine their association with gestational weight gain (GWG). Materials and Methods: This secondary data analysis of a randomized controlled trial of two gestational diabetes screening approaches included 641 individuals with primary exposures and outcomes data. Food timing indicators (i.e., first and last eating episode time, caloric midpoint time, and the total eating window) were assessed using two 24-hour dietary recalls conducted in midpregnancy. Latent profile analysis was used to identify distinct food timing profiles based on these indicators. Regression analyses explored the associations between individual food intake timing indicators, food timing profiles, and GWG. Results: We identified four food timing profiles: extended window eating (n = 133; earliest first eating episode and the longest eating window), restricted window eating (n = 120; latest first eating episode and shortest eating window), early eating (n = 188; earliest caloric midpoint), and typical eating (n = 200; food intake aligning with the sample median). Participants with a restricted window eating profile (vs. typical eating profile) had an increased risk of insufficient GWG (unadjusted relative risk [RR] = 1.85, 95% confidence interval [CI] 1.12, 3.05). Each hour increase in the timing of the last eating episode was associated with 0.39 kg (0.03, 0.75) higher GWG. Both associations were attenuated in adjusted models and no longer statistically significant in adjusted models. Conclusions: We identified four distinct midpregnancy food timing profiles, but these profiles were not independently associated with GWG. These findings suggest that midpregnancy food timing may not play a major role in GWG.