shorty Americans

I read a short article in the December issue of National Geographic Magazine about a study published in Social Science Quarterly which reports that American's height began to level off in the 1950's while Europe saw a steady spurt. The article features a Dutch man who is 6'9.9" tall.  Here's a quote:
         "Komlos's explanation: Europe's universal health care system.  Height  stems from genetics, diet,and  health; good prenatal care and nutrition in early childhood yields taller, healthier adults."  Environment can cause differences of five or six inches," says Ohio State University economist Richard  Steckel.  "That's huge."
Apparently the Netherlands are ranked at the top for child well-being among 21 wealthy nations, while the U.S. ranks in the bottom third.  The average man's height in the Netherlands? born in1910: 5'7.7"  1976: 6'0.4"  And in America? born in 1910: 5'8.1" 1975: 5'10.5"