what influences the red health bar and what influences their health state? I thought the bar and the state were related but some are healthy but the bar is not all the way up.

I thought it was food but that didn't seem to change it either...

The description you see (healthy, weakened, sick, elderly, etc.) is a general status indicator. The health bar indicates, essentially, how many "health points" a villager has. When a villager is sick, injured, starving, etc. they lose health points (you can see that kind of thing in the game log). If the bar goes down enough, their health status changes as their health deteriorates.

ok thanks, that does clarify part of it, but I tried making them eat repeatedly until it didn't say "villager feels better after eating" anymore and the bar didn't go up at all (these ones say "healthy" and the bar is about 3/4 full).

Is it just because it takes some time for the bar to move back up?

How many times did you make them eat? It can take up to 8 times to make a visible difference in the health bar.

oh ok. yeah it did work after about 9 or 10 times , i was trying max 4 times. thanks!