The coronavirus disease 2019 (COVID-19) pandemic has resulted in economic, social, and behavioral changes in people, which may favor several long-term consequences. This study evaluated the effects of the COVID-19 pandemic on eating behavior and mental health in the final phase of social isolation. This cross-sectional study included 756 adults that completed an online questionnaire. Individuals were stratified into those who had been infected with COVID-19 (GCOV) and those who did not (GNCOV). The GCOV group had higher weight (p= 0.013), body mass index (BMI) (p= 0.005), anxiety levels (p= 0.040), sleep disorders (p= 0.009), and poorer sleep quality (p= 0.0028). In the GCOV, the consumption of ultra-processed foods was associated with higher anxiety levels and poorer sleep quality. A higher proportion of individuals who consumed more than five servings of in natura food was observed in the group with taste and olfactory dysfunction than in the group without. Obesity contributes to uncontrolled and emotional eating disorders, increased anxiety, and worsened sleep. Therefore, COVID-19 impaired mental health and eating behavior even in the long term. These changes were potentiated by the presence of obesity and consumption of ultra-processed foods, evidencing the importance of monitoring these individuals even after the resolution of COVID-19.