COVID-19 may cause an anorexic situation. This in turn leads to underfeeding, puts the patient in an energy protein malnutrition state, develops the hyperinflammation, weakens the immunity, and makes COVID-19 conditions more dangerous. Meanwhile, the more severe inflammation conditions in the body, the more severe the anorexia, which in turn affect the disease severity. Studies evaluating appetite in COVID-19 patients are very rare; therefore, we evaluated anorexia and analyzed the related factors in patients with COVID-19.

In this cross sectional study, adult patients’ ≥18 years old with the positive real-time fluorescence polymerase chain reaction for COVID-19 were included. The patients were classified as mild, moderate, and severe based on the WHO classification. We measured the appetite score, weight, height, body mass index (BMI), depression and anxiety score, at admission for every patient.

A total of 301 patients participated in the study. The prevalence of admission anorexia was 58%, and this rate was significantly more in the severe group compared to the mild and moderate groups (P<0.001). Comorbidities, depression and anxiety were independently correlated with anorexia risk [(OR=3.6, 95% CI 1.68–7.70, P=0.001), (OR=1.23, 95% CI 1.16–1.30, P<0001), and (OR=1.24, 95% CI 1.17–1.31, P<0001)], respectively. This correlation was adherence to a U-shape association for BMI, which means BMI<18.5 (OR=3.35, 95% CI 1.8–10.42, P<0001) and BMI ≥30 (OR=2.45, 95% CI 1.02–6.53, P=0.048) were related to higher risk of anorexia.

We reported a high prevalence of anorexia (58%) in COVID-19 patients, which was positively correlated with disease severity. Furthermore, any factor worsening inflammatory state, including underweight, obesity, comorbidities, depression and anxiety can exacerbate anorexia in these patients.