This fact comes from the 2016 book “American Amnesia: How the War on Government Led Us to Forget What Made America Prosper” by Paul Pierson and Jacob Hacker.
Not to keep you in suspense any longer but the shocking fact is,
Americans are no longer the tallest people in the world.
Because the richest country in the world decided about 40 years ago that government would focus the country's wealth on further enriching the wealthy and further empowering the powerful.
Everyone was supposed to be better off according to the psuedo-science/propaganda of - the trickle down theory, voodoo economics and or the Laffer curve. That was a fantastic lie and a fantastic failure - but not so much so that people aren't convinced to keep falling for it (over and over).
The next time you hear some Republican (or Democrat) pledge not to raise taxes - understand what they really mean,
"Lets keep cutting taxes on the wealthy and raising taxes and fees for the middle class." That way the middle class will be angry because they are paying a lot in taxes and fees but not seeing any benefit because their taxes are used for corporate and other forms of rich-person welfare.
You can come up with some alternate explanation but I'd read the book by Pierson and Hacker before you spend too much time doing your own research or listening to what some talking head on TV or the radio, with a vested interest, wants you to believe.