In brief, a study was conducted which found that even though Americans spend on average twice as much per person on healthcare than their counterparts in the UK, they are far less healthy. While being richer did tend to correspond with better health, the richest Americans ranked right around the poorest Brits.
Several possible factors and explanations were looked at, such as taking minorities out of the equation and factoring in what would happen if the average Brit weighed as much as the average American (the standard obesity crisis theory). None explained the gap in health. Of course, this excerpt:
taken from this article might offer an insight to certain, let's call them, "environmental factors" which might have an effect on one's health, over time.
Statutory minimum annual leave plus public holidays UK: 28 days (four weeks + public holidays) US: 10 days (0 weeks + public holidays)