In the United States, about $5,200 per person per year is spent on health care, while in Britain the amount is about half that. A recent study indicated that middle-aged white Americans have a significantly higher rate of diabetes and heart disease than do middle-aged white Britons. Even after eliminating from the study the lifestyle differences of diet, exercise, smoking, and drinking, the data showed that the Americans have poorer health than their British counterparts.
The statements above, if true, best support which of the following assertions?