We’ve known this about respiratory viruses and vitamin D3 blood serum levels for a long time.
Obese people have lower blood levels of vitamin D, since it is fat soluble. There is more storage area for vitamin D, so less circulates.
Obesity is also connected with blood sugar issues and diabetes, all of which are connected to covid risks.
I’ve read that an increase in adipose tissue is an increase in ACE2 receptors which the virus needs to replicate.
Kids have very few ACE2 receptors.
Average BMI for hospitalized COVID patients was found to be over 43 in one study. That’s remarkably overweight.