INTRODUCTION: Underreporting of food intake corresponds to distortions in self-reported food consumption and can lead to inadequacies in dietary prescriptions, which play an important role in preventing excessive weight gain during pregnancy. Recent studies in the field of chrononutrition indicate that meal times influence the quality, quantity, and distribution of calories throughout the day. OBJECTIVE: To evaluate the association of energy intake underreporting with chrononutritional and clinical variables throughout pregnancy. MATERIAL AND METHODS: Prospective cohort study carried out with 100 pregnant women followed up in the three gestational trimesters. Food intake assessment was conducted using three 24-h dietary recalls. Chrononutritional variables evaluated included eating duration, overnight fasting, timing of first and last meals, and the number of eating episodes. The clinical variables evaluated were the adequacy of weight gain and fasting glucose. The occurrence of underreporting was calculated using the Goldberg method and the pregnant women were categorized into three groups: Underreporters (UR), Potential Underreporters (PUR) and Normal Reporters (NR). Generalized estimating equations (GEE) adjusted for confounders were used to assess the association between three groups of levels of energy notification (independent variables) and chrononutritional and clinical variables (dependent variables) throughout pregnancy. RESULTS: Underreporters group reported having first meal later (mean ± standard error: UR-9:26 ± 0:11 vs PUR-8:34 ± 0:09 and NR-8:32 ± 0:08), last meal earlier (UR-19:47 ± 0:10 vs PUR-20:17 ± 0:07 and NR-20:46 ± 0:08), shorter eating duration (UR-10:22 ± 0:14 vs PUR-11:43 ± 0:12 and NR-12:12 ± 0:12), longer overnight fasting (UR-10:58 ± 0:08 vs PUR-10:30 ± 0:08 and NR-10:05 ± 0:08), lower number of eating episodes (UR-4.16 ± 0.13 vs PUR-4.90 ± 0.12 and NR-5.11 ± 0.12), exhibited higher fasting glucose (UR-80.33 ± 1.30 vs NR-74.45 ± 1.90) during pregnancy and greater excessive weight gain in the third trimester (UR-2.20 ± 0.26 vs NR-1.58 ± 0.19). CONCLUSION: Distinct chrononutritional patterns observed in women who underreported food intake suggest that underreporting is associated not only with overall food intake but also with meal patterns, particularly the timing of the first and last meals of the day. Further studies are needed to validate this hypothesis.