Obesity is strongly and independently associated with an increased risk of severe illness and death from coronavirus disease 2019 (COVID-19). The pathophysiological changes that result from elevated body weight lead to metabolic dysfunction, chronic inflammation, impaired immunological responses, and multisystem disorders, which increase vulnerability to severe illness from COVID-19. While vaccination strategies are under way across the world, the second and third waves of the pandemic, along with the emergence of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains, continue to threaten the stability of medical systems worldwide. Furthermore, evidence from previous pandemics suggests that vaccines are less effective in obese individuals than in their healthy-weight counterparts over the long term. Therefore, a consideration of lifestyle changes that can boost metabolic health and immunity is critical to reduce the risk of complications and severe illness from viral infection. In this review, we discuss the potential mechanisms linking excess body weight with COVID-19 morbidity. We also present evidence that intermittent fasting (IF), a dietary program that has gained popularity in recent years, may be an effective strategy to improve metabolic health and immunity and thus reduce the impact of obesity on COVID-19 morbidity and mortality. Obesity is a strong risk factor for severe illness and mortality from coronavirus disease 2019 (COVID-19) infection. Mechanisms linking obesity with severe COVID-19 include diabetes-associated hyperglycemia, inflammation, weakened immune function, and metabolic dysfunction.Obese populations have a known history of poor response to vaccination and it is unknown whether this will also affect their vaccine-induced immunity to COVID-19. Therefore, it is important to implement dietary and lifestyle changes that potentially boost metabolic and immune health to mitigate the impacts of COVID-19.Intermittent fasting (IF) is associated with weight loss, improved glucose homeostasis, metabolic health restoration, and strengthened immune responses.Amid COVID-19 lockdowns, which are associated with more-sedentary lifestyles, the incorporation of IF may be a practical way to curb unhealthy eating habits, maximize healthy lifestyles, and improve mood and emotional well-being.