Most studies of Greco-Roman diet and nutrition have tended to be largely descriptive and to focus primarily on the rich and sophisticated diet of the wealthy, which is very well attested by a range of literary sources. Nutrition would depend upon social attitudes towards the entitlement of the poor to adequate wages and a healthy diet, and governmental provisions for social welfare and food supply. The good nutrition of the Romans compared to the nineteenth-century working classes is not only clear from the skeletal remains, it can also be corroborated by a comparison of the distribution of income, and of the wages and living standards of the poor and the middle classes in the two societies. Most economic historians, who have analysed Roman GDP, have tended to rely heavily upon conjecture and a number of conventional assumptions about the structure of Roman Society.