I don't mean be invidious, but being overweight is an actual medical problem, one that's been strongly linked[1][2][3] with susceptibility and severity of the disease.

I can't recommend reading the World Obesity Atlas pdf enough as it provides possible explanations for the disparities in cases and deaths we've seen in different societies.

[1] https://www.worldobesity.org/resources/resource-library/covi...

[2] https://www.gov.uk/government/publications/excess-weight-and...

[3] https://pubmed.ncbi.nlm.nih.gov/32788355/