If you are talking about human health, it might be that any gravity bellow 0.8g is almost as bad for human health as microgravity. It could be that any gravity above 0.1g is as good as 1g for human health. We simply don't know the format of that curve. We have no data on it even on rodents (the ISS module for that was scrapped). We only know that 1g is good and microgravity is bad. And that very high g is bad too.