The Maya and Aztec diets were actually very balanced, and people were generally healthy. They mainly ate maize, beans and squash and drank chocolate, as well as catching fish and animals.
The Spanish brought cows and pigs, and these took up a large amount of the farmland that the Maya and Aztec had previously used to grow their food.
As a result, after the Spanish conquest food was in short supply, and much less varied. Eventually, the native farming systems collapsed. This led to poor health and many people died.
