Much has been written about the spread of Old World crops and livestock in the Americas. However, very little is known, except in very general terms, about the availability of different foods, diets and nutrition, particularly among the common people, in different regions of Spanish America in the early colonial period. This derives in part from the shortage of evidence, but it also reflects the difficulties of researching these complex issues, where environmental conditions, access to land and labor, income distribution, regulation of food supplies and prices, as well as food traditions, all interact.