Coronavirus disease 2019 pandemic and alterations of body composition

Purpose of review This manuscript reviews evidence collected during COVID-19 pandemic and provides information on the impact of body composition on severity and outcomes of the disease, analysing methods used for body composition assessment. Malnutrition-screening tools will also be discussed to screen and diagnose the patients at higher risk of COVID-19 severity and related worse outcomes. Recent findings COVID-19 can occur in a wide range of presentation, from asymptomatic to severe forms. Among the major risk factors for worse severity, overnutrition, undernutrition and body composition play a role in the ability to respond to SARS-CoV-2 infection. Excess fat accumulation (i.e. obesity) or lean mass loss and functionality (i.e. sarcopenia) or a combination of both (i.e. sarcopenic obesity) can affect whole-body functioning. These body composition alterations in the short-term can influence susceptibility and immunological responses to the virus, inflammatory reaction, metabolic and respiratory distress, while in the long-term can modulate disease outcomes, namely length of stay, time required for recovery, risk of ICU-acquired weakness and long-term disabilities, and potentially increase the risk of death. Individuals with malnutrition, sarcopenia, obesity, sarcopenic obesity and older adults with abnormal body composition or malnutrition risk may require tailored medical nutrition therapy to improve short and long-term COVID-19 outcomes.