more poor on average than whites and asians.  Being poor means they rely more on public transit, live in closer quarters, work in "essential jobs" and so must continue to work around others while many stay home.  Etc.

I beleive blacks have a higher % of obesity as well.  That's another contributing factor.

I'm positive we will find that poor whites are also affected at a higher rate than the median household.

https://upload.wikimedia.org/wikipedia/commons/thumb/2/23/ObesitySexRace2016.png/1024px-ObesitySexRace2016.png