1. A study by the Center for Clinical Sciences at the Japan Institute for Health Security found that underweight individuals are at a higher risk of developing severe COVID-19 symptoms compared to those with normal weight.

2. Underweight patients were 1.74 times more likely to require ventilators or ECMO machines, and this risk increased to 1.89 times when looking only at the likelihood of death.

3. The study particularly highlighted an increased risk among underweight individuals aged between 20 and 64 years old, with them being 2.37 times more likely to suffer severe symptoms and 5.75 times more likely to die than their counterparts with normal weight.