"Stable carbon and nitrogen isotopes of human dental calculus: a potentially new non-destructive proxy for paleodietary analysis":

Abstract
Fifty-eight dental calculus samples from medieval and post-medieval skeletons from Vitoria, Spain, and a single sample from an Alaskan Inuit were tested for stable carbon and nitrogen isotope compositions. There was sufficient carbon and nitrogen concentrations to obtain δ13C and δ15N values, and the samples from Spain produced results that were replicable and comparable to European isotope values based on bone collagen collected from literature sources. The Alaskan Inuit calculus sample yielded a δ15N value of +17.5‰, well beyond the range of the Spanish samples, but consistent with literature data for modern Greenlandic Inuit consuming a diet rich in marine food. There are several potential sources for carbon and nitrogen in calculus. The results of this study yield stable isotope values consistent with those obtained from other biomaterials used as isotope proxies for paleodietary research, including bone collagen, hair, and fingernails, although further work is necessary to verify the fidelity of calculus as an isotope proxy. Many studies in bioarchaeology are precluded by curatorial concerns regarding the destructive analysis of primary biomaterials. However, calculus is an “add-on”, or secondary biomaterial, that is not an integral part of the dental or skeletal system. Hence, its consumption during analysis is technically not destructive. Therefore, isotope analysis of dental calculus may provide a potential new avenue for paleodietary analysis where the use of other primary biomaterials is precluded
ScienceDirect.com - Journal of Archaeological Science - Stable carbon and nitrogen isotopes of human dental calculus: a potentially new non-destructive proxy for paleodietary analysis



Also, isn't this interesting?

A regional investigation of subadult dietary patterns and health in late Iron Age and Roman Dorset, England

Abstract
This is the first regional analysis of the impact of Romanisation on subadult dietary patterns and related health parameters in Britain. A sample of 200 subadults from late Iron Age (LIA) and Romano-British (RB) Dorset were examined for dental health and specific metabolic diseases, and a sub-sample of 29 individuals were selected for nitrogen and carbon isotope analysis. The results showed that dental health declined in the Romano-British period and the incidence of scurvy and rickets rose. Increased consumption of marine foods in the RB period is indicated by an increase in δ13C between the LIA and RB subadults. After early childhood, there was no age-dependent variation in dietary protein in the RB and LIA populations from Dorset. We propose that these changes related to the introduction of urban living, Romanised diets and population migration.
http://www.sciencedirect.com/science...05440311004705

It sounds like the "Romanised diet" may have been something of the Iron Age equivalent of what Weston Price called "the displacing foods of modern commerce" in the 19th and 20th centuries. Empire bringing worse nutrition in its wake.

Maybe Monty Python had it wrong and the answer to "What did the Romans do for us?" should be the less positive answer: "Rot our teeth and cause scurvy and rickets."