A study found that inner-city kids living in neighborhoods with more green space gained about 13% less weight over a two-year period than kids living where there were less trees and more pavement. It seems that although the size of Americans have changed over the years i.e. Marilyn Monroe was a size 14 and very desirable whereas that is now considered a plus (or close to it) size the real problems began in the 1980s.
Kids grew up in the 80s and are thin so as we are all a product of nature and nuture. In any case those who eat Whoppers and watch much too much television will get fat.
However, "Most experts agree that the changes were related to something in the environment," says social epidemiologist Thomas Glass of the Johns Hopkins Bloomberg School of Public Health. That something could be a shrinking of the green." Interesting!