In 1776, when the American colonies broke from the British Empire, the average American man was 5’9″.

This was three inches taller than the average Englishman. It was taller than the Dutch, taller than the French, taller than the Swedes. George Washington, at 6’2″, was tall by any standard, but his soldiers were not the Lilliputians the popular image suggests. At 5’7″ the average Continental Army private was significantly taller than a typical European soldier, because he had grown up on a diet that the typical European soldier had not.

The American military has been measuring its recruits since the Revolutionary War.

In 1776, the average Continental soldier was taller than the average European soldier.
In 1950, the average American draftee was taller than any European conscript.
In 2026, the US military has a recruitment crisis partly attributed to the physical condition of the available pool.

The diet changed in between.

The records are public.

Nobody is connecting the columns.

The diet was meat. Dairy. Eggs from the back garden. Game from the woods that belonged to nobody. The abundance of colonial America, where the protein was not controlled by a landlord or rationed by a church or restricted by a forest law, had produced a population that was, by the skeletal standards of the eighteenth century, the tallest on earth.

Americans stayed the tallest people in the world for nearly two hundred years.

Then they stopped.

American height plateaued in the 1950s. It has not meaningfully increased since. The average American man born in 1996 is approximately 5’9″, which is the same height as the average American man born in 1950, and roughly the same height as the average American man in 1776.

In the same period, the Dutch grew six inches. The Scandinavians grew five. The Germans grew four. The South Koreans grew nearly four. One by one, the European populations that had been shorter than Americans in 1900 overtook them. The Dutch, who had been among the shortest Europeans in 1860, are now the tallest people on earth at an average of 6 foot for men. Americans have dropped to 37th.

Thirty-seventh.

The richest country in the history of the world, spending more per capita on food than almost any other nation, is now shorter than the Dutch, the Danes, the Norwegians, the Swedes, the Germans, the Croatians, the Czechs, the Estonians, the Latvians, the Lithuanians, the Slovenians, the Montenegrins, the Bosnians, the Serbs, the Icelanders, the Belgians, the Austrians, the Swiss, the Australians, the New Zealanders, the Canadians, the Bermudans, and the Finns.

The conventional explanation blames inequality. Healthcare access. Poverty. These are real factors. They are also downstream of something more fundamental.
The American diet changed.

In the 1950s, the average American ate butter, whole milk, eggs, and red meat as the nutritional backbone of the diet. By the 1990s, the average American was eating margarine, skimmed milk, egg whites, chicken breast, and a long list of processed foods that had been reformulated to remove animal fat and replace it with sugar and seed oil, because the dietary guidelines had told them to.

The Dutch, in the same period, continued eating dairy. Full-fat dairy. Roughly a kilogram per person per day. Cheese for breakfast. Cheese for lunch. Milk with dinner. Butter on everything. The Dutch ignored the American dietary guidelines and kept eating the food that was making them tall.

The Americans followed the guidelines and stopped growing.

The Dutch ignored the guidelines and became the tallest people on earth.

The experiment has been running for fifty years. It is running in real time. The results are in the conscription records and the school growth charts and the anthropometric surveys that are published every year and that nobody in a position to update the dietary guidance appears to be reading.

America was the tallest country on earth when it was eating butter.

America is the 37th tallest country on earth now that it is eating the guidelines.

The guidelines have not been updated.

The Dutch are still eating the cheese.