In the mid-1800s, the average Dutch man was 5'4". Shorter than the average American. Shorter than most of their European neighbours. Today the average Dutch man is 6'0". The tallest national population on earth. That is a 20-centimetre transformation in about 150 years. One of the fastest documented height increases in human history. What drove it? Researchers are consistent: dairy. Meat. High-quality animal protein at scale, democratised across the population as prosperity spread. The Netherlands is a dairy farming country. It always was. What changed was that ordinary people, not just the wealthy, could access what the land produced. The Dutch didn't get taller because of a new crop. They got taller because of a cow.