Background: Humankind have faced unexperienced pandemic events since 2020. After COVID-19 pandemic is calming down, we felt the need to verify whether in-hospital mortality had worsened compared to pre-pandemic conditions due to the COVID-19 pandemic. Objective: To test the hypothesis that daily food consumption is associated with in-hospital mortality during hospitalization and to provide baseline data to examine the effects of COVID-19 in post-pandemic exists or not. Methods: All hospitalized patients staying in a single institution on the third Thursday of May, August, November, and the following next February were included. Compared data: 1) among four seasons, 2) between age < vs.