• diabetes mellitus
• endocrinology
• nutritional sciences
• policy

In the current COVID-19 pandemic, governments mandate social distancing and good hand hygiene, but little attention is paid to the potential impact of diet on health outcomes. Poor diet is the most significant contributor to the burden of chronic, lifestyle-related diseases like obesity, type 2 diabetes and cardiovascular disease.1 As of 30 May 2020, the Centers for Disease Control and Prevention reported that among COVID-19 cases, the two most common underlying health conditions were cardiovascular disease (32%) and diabetes (30%).2 Hospitalisations were six times higher among patients with a reported underlying condition (45.4%) than those without reported underlying conditions (7.6%). Deaths were 12 times higher among patients with reported underlying conditions (19.5%) compared to those without reported underlying conditions (1.6%).2 Two-thirds of people in the UK who have fallen seriously ill with COVID-19 were overweight or obese and 99% of deaths in Italy have been in patients with pre-existing conditions, such as hypertension, diabetes and heart disease.3 These conditions, collectively known as metabolic syndrome, are linked to impaired immune function,4 and more severe symptoms and complications from COVID-19.5

A major factor that drives the pathophysiology of metabolic syndrome is insulin resistance,6 defined as an impaired biological response to insulin, the hormone that regulates …