This is still the view in much scholarly writing on the Roman Empire. Yet it is inconsistent with what physical anthropologists are discovering through analysis of skeletal remains. The latest of these studies concerns child burials from 3rd to 5th century Roman Dorchester, in southern England. The children show high levels of malnutrition and trauma: 38.5% had cribra orbitalia—a sign of iron or vitamin B12 deficiency; 12.5% had rickets—a sign of vitamin D deficiency; 4.8% had scurvy—a sign of vitamin C deficiency; and 5.4% had broken ribs (Lewis, 2010).
These rates are much higher than those for medieval England and point to a very poor diet. The incidence of rickets is interesting, since we see a similar high prevalence in industrial England (18th – early 20th centuries). The latter rickets epidemic is usually attributed to industrial smog that blocked UVB radiation and thus impaired vitamin-D synthesis in the skin. A likelier culprit is a diet made up almost wholly of bread, whose high content of phytic acid increases vitamin-D requirements by binding to calcium and phosphorus in the body, thus making these elements unusable (Lindeberg, 1997). This is also probably the cause of Roman-era rickets.
Lewis (2010) cites similar findings from other Roman sites:
Many questions remain about what impact the introduction of urban centers and the gradual economic decline at the end of the Roman Empire had on the local population. Some Roman scholars argue that “Romanization” brought about improvements to the health of the people (Mattingly, 2006, p. 323), with the writing of Roman architects such as Vitruvius conjuring up images of planned Roman cities, with marbled surfaces and flowing water, providing extensive facilities for the comfort and health of the inhabitants (Morley, 2005). Diametrically opposed is the argument that urbanization widened the divide between the rich and the poor, with many suffering hardships of poverty, social unrest, and subservience to the conquering population. The city of Rome itself is seen as overcrowded and filthy, with dogs and muggers prowling the streets, whereas the archaeological evidence calls into question the organization of the water supply and levels of sanitation, with latrines discovered near kitchen areas (Laurence, 1997; Morley, 2005). Garnsey (1999) has hypothesized that undernutrition was endemic in the urban communities of the Greco-Roman world …
Although the Roman Empire brought about an increase in economic wealth, much of this increase seems to have been either siphoned off by the elite or consumed by the large standing army. There is very little evidence that the average citizens were better off under imperial rule, and much suggests that they were worse off.
Why? One reason may be ‘diseconomies of scale.’ Empires tend to liquidate smaller communal entities that more efficiently deliver collective goods, such as community policing, high-trust social networks (for exchange of services and sharing of scarce goods), and support for family formation and child care. This is particularly evident in the Roman Empire’s high infantile mortality rate and low birth rate, with the result that natural increase became negative in late imperial times.
These smaller communal entities were liquidated by the tendency of individuals to migrate from one part of the Empire to another, either on their own or through resettlement of legionnaire veterans. This process of liquidation was also assisted by the State itself, which saw private collectivities as sources of conspiracy or rebellion. In fact, only a limited number of non-State associations were allowed, such as guilds, burial clubs, and officially recognized religions. The persecution of Christians was part of this tendency to see smaller collectivities as threats to the Empire.
Many of us, living in countries where for several centuries we have had fair liberty of association, may not realize just how recent such freedom is but realize that a civilization in which states fear their own citizens is one that recognizes its own inhumanity. Thus it cannot surprise us that in Antiquity most noncommercial associations were forbidden: the authorities realized that any social club might be a center for opposition to the régime. (source)
Empires also make life worse for the average person by fostering dependence on long-distance economic relationships that may collapse if one link in the supply chain disappears. When barbarian invasion disrupted grain shipments between North Africa and Italy in the 5th century, urban populations were suddenly without food. In general, empires create relationships between people who have no commitment to each other beyond short-term economic interest. When a crisis happens, these same people will give priority to their kinfolk … thus leaving in the cold any atomized individuals with no kinship networks to fall back on. When the Roman Empire collapsed, the latter were the ones who suffered the most.
References
Lewis, M.E. (2010). Life and death in a civitas capital: metabolic disease and trauma in the children from late Roman Dorchester, Dorset, American Journal of Physical Anthropology, early view.
Lindeberg, S. (1997), Cereal grains, Paleolithic Diet Symposium List, http://www.paleodiet.com/phytic.txt