For all you vegetarians out there...
By 1776 the average American soldier stood nearly three inches taller than the redcoat sent to put him down.
They were the same people. Same villages, same surnames, same blood, separated by three or four generations and one ocean.
The Englishman had grown up on bread and the game laws. His deer belonged to the king, his rabbits to the squire, and his common had been fenced.
The American had grown up in a country with no lord, no keeper and no forest law. William Penn wrote the right to hunt and fish into Pennsylvania's founding charter. Vermont put it in its constitution.
Colonial Americans ate somewhere between 150 and 200lb of meat a year each. Emigrants wrote the same line home for 200 years: we have meat three times a day.
Height is what a childhood of meat looks like from the outside.
England proves it from the other direction. In 1800 a 14 year old cadet at Sandhurst, raised on beef and mutton, stood about eight inches taller than a 14 year old from the London slums recruited for the navy.
So the English ruling class knew perfectly well what meat does to a child. They had the evidence at their own dinner table.
They simply kept it there. The ones who got away grew three inches and then beat them in a war.