Lifestyle factors such as dietary habits, perceived weight, sleep, and physical activity worsened during the COVID-19 pandemic. Through this study, we aimed to understand the impact of COVID-19 on these lifestyle factors in Bahrain. A cross-sectional study was conducted among 1005 adult Bahrainis. Data were collected online using a structured and validated questionnaire for the assessment of eating habits, physical activity, and lifestyle during the COVID-19 pandemic. Participants were snowballed through those who agreed to answer the online questionnaire. There was a higher consumption of fast food, and a higher dependence on takeaways during the COVID-19 pandemic. About 63.5% of the participants consumed >4 meals per day, compared to 36.5% before the COVID-19. About 30% reported consumption of sugar sweetened beverages from two to three times a day. Weight loss was predominantly observed in persons exercising 1–3 times a week. The consumption of sugar-sweetened beverages was also high, with about 19% reporting drinking sweet beverages once every day, 10.6% from two to three times a day, and 40.4% from one to four times a week. A higher proportion of the participants reported poor sleep quality during the pandemic (31.2%) compared to before (12.2%), and 39.7% of the participants reported feeling lazy. Screen time use also doubled during the pandemic, with participants spending more than five hours per day on screens for entertainment, which went from 22.4% before to 51.9% during the pandemic. The lifestyle and dietary habits changed drastically for our study participants during the pandemic. The increased reliance on processed fast food instead of healthier options is a challenge to be tackled in any future pandemic situation. Future research needs to focus on strategies to promote healthier lifestyle modifications during situations such as the COVID-19 pandemic.