The other days I was thinking; if the dawn of agriculture 10,000 years ago resulted in a 4" decrease to our height, isn't it possible the processed food era is doing the same?

Here is an article from 2004 that says height in the US is decreasing, while height in Europe is on the rise...

"America has eight million people with no job, 40 million individuals with no health insurance, 35 million living below the poverty line, and a population that exists mainly on junk food. There, the rise in average height that marked its progress as a nation through the 19th and 20th centuries has stopped and has actually reversed - albeit very slightly - in recent years. Many Americans are rich and do well anatomically as a result, but there is a large underclass that is starting to drag the country down the stature charts."

Americans shrinking as junk food takes its toll