The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. 
The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. 
The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. 
The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

Obesity is a rapidly increasing public health problem, with surveillance most often based on self-reported values of height and weight. We conducted a systematic review to determine what empirical evidence exists regarding the agreement between objective (measured) and subjective (reported) measures in assessing height, weight and body mass index (BMI). Five electronic databases were searched to identify observational and experimental studies on adult populations over the age of 18. Searching identified 64 citations that met the eligibility criteria and examined the relationship between self-reported and directly measured height or weight. Overall, the data show trends of under-reporting for weight and BMI and over-reporting for height, although the degree of the trend varies for men and women and the characteristics of the population being examined. Standard deviations were large indicating that there is a great deal of individual variability in reporting of results. Combining the results quantitatively was not possible because of the poor reporting of outcomes of interest. Accurate estimation of these variables is important as data from population studies such as those included in this review are often used to generate regional and national estimates of overweight and obesity and are in turn used by decision makers to allocate resources and set priorities in health.

A comparison of direct vs. self-report measures for assessing height, weight and body mass index: a systematic review

https://www.healio.com/psychiatry/journals/psycann/1976-12-6-12/{806b8887-c02e-40c8-a228-57f1cdb2bdba}/the-stress-of-life.pdf

The stress of life

Objective: To assess the validity of self-reported height and weight by comparison with measured height and weight in a sample of middle-aged men and women, and to determine the extent of misclassification of body mass index (BMI) arising from differences between self-reported and measured values. Design: Analysis of self-reported and measured height and weight data from participants in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). Subjects: Four thousand eight hundred and eight British men and women aged 35-76 years. Results: Spearman rank correlations between self-reported and measured height, weight and BMI were high (r > 0.9, P < 0.0001). Height was overestimated by a mean of 1.23 (95% confidence interval (CI) 1.11-1.34) cm in men and 0.60 (0.51-0.70) cm in women; the extent of overestimation was greater in older men and women, shorter men and heavier women. Weight was underestimated by a mean of 1.85 (1.72-1.99) kg in men and 1.40 (1.31-1.49) kg in women; the extent of underestimation was greater in heavier men and women, but did not vary with age or height. Using standard categories of BMI, 22.4% of men and 18.0% of women were classified incorrectly based on self-reported height and weight. After correcting the self-reported values using predictive equations derived from a 10% sample of subjects, misclassification decreased to 15.2% in men and 13.8% in women. Conclusions: Self-reported height and weight data are valid for identifying relationships in epidemiological studies. In analyses where anthropometric factors are the primary variables of interest, measurements in a representative sample of the study population can be used to improve the accuracy of estimates of height, weight and BMI.

/pdf/validity-of-self-reported-height-and-weight-in-4808-epic-31r6o4zalr.pdf

Validity of self-reported height and weight in 4808 EPIC-Oxford participants.

Dental enamel hypoplasias are deficiencies in enamel thickness resulting from physiological perturbations (stress) during the secretory phase of amelogenesis. The results of a wide variety of experimental, clinical, and epidemiological studies strongly suggest that these defects and their associated histological abnormalities (such as accentuated stria of Retzius and Wilson bands) are relatively sensitive and nonspecific indicators of stress. Because of the inability of enamel to remodel, and the regular and ring-like nature of their development, these defects can provide an indelible, chronological record of stress during tooth crown formation. For these reasons, along with the ease with which they are studied, enamel hypoplasias have been increasingly employed as indicators of nutritional and disease status in paleopathology, and their study has begun to extend into other subdisciplines of physical anthropology.



In order to provide the reader with a better understanding of the current issues in this field, we first review normal enamel development, historical advances in the study of enamel developmental abnormalities, and provide a threshold model to help conceptualize the etiology of enamel developmental defects. Specific attention is then centered on extant, fundamental issues in the use of enamel hypoplasias and histological structures as epidemiological indicators of nonspecific stress.



Most enamel hypoplasias are associated with abnormal histological changes (accentuated stria of Retzius or “Wilson” and “Cluster” bands). However, the lack of association of some mild surface irregularities, characteristically seen as thin, perikymata-like surface depressions, with abnormal prism morphology suggests that these surface features may not be evidence of physiological perturbation.



Methods now exist to reliably identify both histological and enamel surface defects. However, further research is needed on methods for determining the size of defects and the epidemiological significance of defect widths and depths. Similarly, the general relationship between the location of enamel hypoplasias and associated histological structures on the one hand, and an individual's age at the time of their development on the other hand, is also well understood. However, better estimates of intra- and inter-population variation in the timing of enamel matrix formation are needed before these defects can reach their full potential as chronometric measures of stresses.



Lack of understanding patterns of differential susceptibility of enamekl to developmental disruption has likely hindered interpretations of the results of a number of past experiments. The seemingly strong pattern of differential suscetibility of enamel to disruption-within teeth and across tooth classes, dentitions, and taxa-may yield a number of significant clues to understanding basic issues in enamel development.



Populations that are exposed to a high degree of undernutrition and disease, from prehistoric to contemporary times, share high rates of linear enamel hypoplasias. While these defects seem to relate to bouts of undernutrition and infection, their specific etiology is still unknown. In the next decade we expect to develop more precise information on the specificity and sensitivity of secretory ameloblaste to disruption. A variety of research directions are suggested for further anthropological study.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/ajpa.1330330506

Assessment of systemic physiological perturbations from dental enamel hypoplasias and associated histological structures

The Osteological Paradox: Problems of Inferring Prehistoric Health from Skeletal Samples [and Comments and Reply]

Prevalence and the duration of linear enamel hypoplasia: a comparative study of Neandertals and Inuit foragers.

Hacking trauma is often encountered in forensic cases, but little experimental research has been conducted that would allow for the recognition of wounds caused by specific weapon types. In this paper, we report the results of a hacking trauma caused by machete, cleaver, and axe weapons and the characteristics of each weapon type on bone. Each weapon type was employed in multiple trials on pig (Sus scrofa) bones and then the wounds were examined macroscopically for several characteristics that serve to differentiate the weapons.

Macroscopic characteristics of hacking trauma.

The arrival of Europeans in the New World had profound and long-lasting results for the native peoples. The record for the impact of this fundamental change in culture, society, and biology of Native Americans is well documented historically. This paper reviews the biological impact of the arrival of Europeans on native populations via the study of pre- and postcontact skeletal remains in Spanish Florida, the region today represented by coastal Georgia and northern Florida. The postcontact skeletal series, mostly drawn from Roman Catholic mission sites, are among the most comprehensive in the Americas, providing a compelling picture of adaptation and stress in this setting. Study of paleopathology, dental and skeletal indicators of physiological stress, stable isotope (carbon and nitrogen) analysis, tooth microwear, and skeletal morphology (cross-sectional geometry) reveals major alterations in quality of life and lifestyle. The bioarchaeological record indicates a general deterioration in health, declining dietary diversity and nutritional quality, and increasing workload in the contact period. The impact of contact in Spanish Florida appears to have been more dramatic in comparison with other regions, which likely reflects the different nature of contact relations in this setting versus other areas (e.g., New England, New France). The bioarchaeological record represents an important information source for understanding the dynamics of biocultural change resulting from colonization and conquest.

/pdf/frontiers-of-contact-bioarchaeology-of-spanish-florida-32vxf3ewde.pdf

Dale L. Hutchinson

Papers

The Osteological Paradox: Problems of Inferring Prehistoric Health from Skeletal Samples [and Comments and Reply]

Prevalence and the duration of linear enamel hypoplasia: a comparative study of Neandertals and Inuit foragers.

Macroscopic characteristics of hacking trauma.

Frontiers of contact: Bioarchaeology of Spanish Florida

Determination of stress episode duration from linear enamel hypoplasias: a case study from St. Catherines Island, Georgia.