BACKGROUND: Covid-19 is one of the world’s major pandemics. It has affected millions of people in various ways. OBJECTIVE: This study investigates the influence of pandemic-induced shifts in eating and sleeping behaviors on the psychological well-being of university students. METHODS: The study adopted a cross-sectional research design. A total of 604 students participated in the study. The Personal Form, the Psychological Well-Being Index, and the Pittsburgh Sleep Quality Index were used to collect data. The research was conducted between October 2021 and December 2022. RESULTS: The participants reported a mean psychological well-being score of 40.76±9.38, alongside a Pittsburgh Sleep Quality Index score of 7.46±3.30. Analysis revealed a significant negative correlation between the mean psychological well-being scores and the Pittsburgh Sleep Quality Index scores (p < 0.01). Throughout the pandemic, the participants experienced a decline in physical activity, an increase in their body weight, and a change in their eating habits. While psychological well-being remained relatively high, sleep quality was notably poor. Notably, improvements in psychological well-being corresponded with enhancements in sleep quality, suggesting a reciprocal relationship between the two variables. CONCLUSIONS: The pandemic negatively impacted the physical activity and body weight of young adults. This study highlights the importance of promoting physical activity among university students during pandemics and similar crises to reduce adverse effects on body weight. It also highlights the importance of educating students about the importance of healthy sleep and how to maintain good sleep hygiene.