Frances Sladek and researchers study on found 'concerning' changes in gene expression in subjects that followed diets high in fat. Researchers said their study demonstrates high-fat diets not only affect the genes linked to obesity, colon cancer and irritable bowls, but  also have an impact on genes related to the immune system, brain function and risk of Covid-19. Results of the study showed high-fat diets increased the gene expression of proteins in the body that are used by COVID spike proteins to enter and infect a host.