COVID-19 is a global pandemic that originated in 2019 and spread across the globe with severe respiratory symptoms caused by Coronavirus-2. Various swift protective measures have been implemented by countries worldwide to mitigate the spread of COVID-19, including movement restrictions and stay-at-home restrictions. This study aimed to determine whether the quarantine period and campus closures negatively affected students in terms of dietary habits and physical activity. In addition, it aimed to investigate the effects of changes in dietary behaviors and physical activity on body weight differences. Cross-sectional research was carried out from February to September 2022. The information was obtained via an online questionnaire using Google Forms. The questionnaire had four parts and 60 questions to examine participants' demographic information, dietary intake, physical activity before and during the pandemic, and nutritional supplement use. The questionnaire was completed by 376 students (165 men and 211 women) between the ages of 18 and 24. A chi-square test, Mann Whitney test, Kruskal–Wallis's analysis, and descriptive analysis were done to analyze the data. Statistical significance is defined as an alpha level of less than 0.05. A preliminary analysis of the study results will provide information regarding the impact of the pandemic on dietary behaviors, physical activity, and body weight changes among university students. Thereupon, during the pandemic, increased dietary intake was reported by about 45% of the sample. In addition, about 46% of the respondents reported in the questionnaire that reducing their level of physical activity during the pandemic. Moreover, there were food groups that were consumed more during the COVID-19 pandemic, such as fish products, dairy products and eggs, meat, and poultry, which have a high biological value (HBV). Furthermore, according to the results, male students gained more weight than female students due to lockdown restrictions, feeling of fear and anxiety, lack of physical activity. Whereas female students are more concerned about their body shape and healthy food intake. Regarding physical activity, the findings were that the study sample was divided into two groups: students who were physically active before the pandemic, then their activity and intensity decreased during the pandemic. The second group of students, who were inactive before the pandemic, increased their activity and intensity. Health professionals and stakeholders should place a high priority on ensuring that students can deal with major life events without affecting their health.