How breakfast changed

In the medieval period, breakfast included fish, beer and wine. Porridges were consumed across meals, not just at breakfast. But, during the Industrial Revolution, people began to spend less time around meals and started to eat light breakfasts.

In the 1920s, Beech-Nut Packing Company wanted to get more people to buy their bacon, so they hired a PR consultant that spread the message that a heavy breakfast would be healthier. And so the meal of bacon (and eggs) became a staple.