Barbara A. Piperata

The nutrition transition in amazonia: Rapid economic change and its impact on growth and development in Ribeirinhos

The goal of this longitudinal study was to assess the impact of economic change and increased market integration on subsistence strategies, living conditions, growth, and nutritional status of Ribeirinhos living in the rural Amazon, Brazil. Data on weight, height, skinfolds, and circumferences, as well as data on economic strategies and living conditions were collected from 469 individuals in 2002 and 429 in 2009. Of these, 204 individuals were measured on both occasions. Independent and paired t-tests were used to identify changes in nutritional status over time in the larger sample and smaller, longitudinal subsample, respectively. Multiple linear regressions were used to examine the relationship between changes in economic/living conditions and nutritional status in the longitudinal subsample. Results indicate modest improvements in linear growth (HAZ) and among male children the observed increase was related to enrollment in the Brazilian conditional cash transfer program, Bolsa Família (P = 0.03). In terms of short-term measures of nutritional status, we found a significant increase in ZTSF and a reduction in ZUMA in most age/sex groups. Among subadults, there was a negative relationship between ZUMA and access to electricity (P = 0.01) and positive relationship between ZUMA and the sale of the açaí fruit (P = 0.04). Significant changes in weight and BMI (P < 0.01) were found among adult females and both were negatively related to household cash income (P = 0.02 and P = 0.03, respectively). Despite significant changes in economic strategies and lifestyle, changes in nutritional status were modest which may be explained by increased food insecurity documented during this early stage of transition.

Energy expenditure among farmers in developing countries: What do we know?

The trend toward overweight and obesity in developing countries is often assumed to be due, in part, to reductions in energy expenditure associated with the transition from agrarian to urban lifestyles. In this article we first review the published studies on energy expenditure in farming populations living in developing countries, populations generally assumed to have high levels of energy expenditure. To facilitate comparison we express energy expenditure as physical activity level (PAL), i.e. the ratio of total daily energy expenditure to basal metabolic rate. Then, with the goal of better understanding variability in energy expenditure between different human groups, we focus on case studies of women farmers in Colombia and Brazil for whom we have good ethnographic data. The published studies reviewed indicate that most farmers have PAL values in the moderate physical activity range, but toward the high end of that range. PAL values of male farmers tend to be higher than female, and show greater seasonal variation. The case studies illustrate that women farmers, living in broadly similar environments, and dependent on the cultivation of the same crop can have quite different patterns of physical activity and hence PAL values. These differences are a function of differences in behavior related to social and cultural variables like the organization of work at the household level and perceptions of how food crops should be processed, as well as micro‐level ecological factors. Am. J. Hum. Biol., 2008.

Nutrition in transition: Dietary patterns of rural Amazonian women during a period of economic change

The goal of this study was to understand the relationship between economic change (wage labor, retirement, and the Bolsa Família program) and dietary patterns in the rural Amazon and to determine the extent to which these changes followed the pattern of the nutrition transition.

Forty days and forty nights: a biocultural perspective on postpartum practices in the Amazon.

The immediate postpartum period is recognized as a special time in many societies and is commonly associated with food and work restrictions. The logic of food restrictions during a period of increased energy and protein needs has been challenged, but few data are available to test the impact of these practices on the diets of lactating women. In the eastern Amazon the immediate postpartum period is referred to as resguardo, lasts for 40-41 days and includes food taboos and work restrictions. Taking a biocultural perspective, this paper combines data on the beliefs and attitudes surrounding the practice of resguardo with quantitative data on the actual dietary intakes and activity patterns of a cohort of 23 lactating women followed from birth through 15 months postpartum. This paper addresses three topics: (1) shared ideals regarding resguardo; (2) adherence to food and work restrictions; and (3) the impact of these practices on womens dietary intakes and energy expenditure. The results show that the majority of women adhered to food taboos and work restrictions. During resguardo energy expenditure in physical activity was lower, reducing womens energy needs and allowing them to devote more time to infant care. However, energy intakes were also lower. The reduction in dietary intake was impacted more by work restrictions and the loss of women in subsistence tasks during resguardo than by adherence to food taboos. In addition to altering maternal energetic strategies, resguardo served an important social function by reinforcing bonds and, for young women, marking the transition to womanhood.

Exploring the multidimensionality of stature variation in the past through comparisons of archaeological and living populations

Adult stature variation is commonly attributed to differential stress-levels during development. However, due to selective mortality and heterogeneous frailty, a populations tall stature may be more indicative of high selective pressures than of positive life conditions. This article examines stature in a biocultural context and draws parallels between bioarchaeological and living populations to explore the multidimensionality of stature variation in the past. This study investigates: 1) stature differences between archaeological populations exposed to low or high stress (inferred from skeletal indicators); 2) similarities in growth retardation patterns between archaeological and living groups; and 3) the apportionment of variance in growth outcomes at the regional level in archaeological and living populations. Anatomical stature estimates were examined in relation to skeletal stress indicators (cribra orbitalia, porotic hyperostosis, linear enamel hypoplasia) in two medieval bioarchaeological populations. Stature and biocultural information were gathered for comparative living samples from South America. Results indicate 1) significant (P < 0.01) differences in stature between groups exposed to different levels of skeletal stress; 2) greater prevalence of stunting among living groups, with similar patterns in socially stratified archaeological and modern groups; and 3) a degree of regional variance in growth outcomes consistent with that observed for highly selected traits. The relationship between early stress and growth is confounded by several factors-including catch-up growth, cultural buffering, and social inequality. The interpretations of early life conditions based on the relationship between stress and stature should be advanced with caution.

Variation in maternal strategies during lactation: the role of the biosocial context.

Compared to other mammals, human milk is dilute which lowers the relative daily cost of lactation allowing women greater flexibility in the strategies they use to meet the energy demands of lactation. These strategies include increasing dietary intake, reducing energy expenditure, and drawing on energy stores. Women are affected by the biosocial context in which they live, including norms regarding the sexual division of labor and diet and activity patterns during lactation, as well as household‐level factors such as economic strategy and the availability of social support. This paper combines longitudinal data on dietary intake, energy expenditure, and body weight of 23 lactating Amazonian women living in a subsistence‐based economy with detailed ethnographic data and considers how adherence to the cultural norms and the availability of social support contributed to intra‐population variation in maternal energetic strategies. Dietary intake was found to vary more than energy expenditure. Adherence to dietary restrictions during the postpartum period of resguardo significantly reduced intra‐population variation in energy intake. Women with social support came closer to achieving energy balance during resguardo (t = 2.8; P = 0.01) and peak lactation (t = 2.7; P = 0.02) and lost less weight (t = 3.6; P = 0.002) than those without such support. Those with social support had higher energy (t = 2.1; P = 0.05) and carbohydrate (t = 2.1, P = 0.05) intakes during resguardo and spent significantly less time in subsistence work during peak (t = 2.6, P = 0.03) and late lactation(t = 2.4, P = 0.03). Case studies are used to place these finding in context. Am. J. Hum. Biol. 2009.

Intra-population variation in anemia status and its relationship to economic status and self-perceived health in the Mexican Family Life Survey: implications for bioarchaeology.

Recently scholars have advocated for the use of a critical biocultural approach in bioarchaeology, where osteological and dental markers of stress are used to understand the broader biosocial context of past populations. However, the ability to accomplish this task rests on the assumption that ultimate-level environmental stressors and well-being in the past can be reconstructed from the prevalence of pathologies in skeletal collections. Here we test this assumption using anemia prevalence in the Mexican Family Life Survey. Specifically we test three hypotheses: (1) that individuals sharing the same household are more likely to share anemia status; (2) anemia status is a predictor of economic status (a common proxy for broader environmental context); and (3) anemia status is related to self-rated health. Results demonstrate that: anemia status was not commonly shared between household members; there was a significant overlap in economic status between anemic and nonanemic individuals (i.e., anemia poorly predicted economic status) and; while anemia status was associated with self-perceived health, the majority of those who reported poor health were nonanemic while a significant number of those who reported very good health were anemic. We argue that these findings are likely related to variation in individual frailty, which is shaped by biological and cultural risk factors. Therefore, we advocate for greater incorporation of individual frailty into bioarchaeological investigations, and, in effort to overcome some of the difficulties associated with this task, increased use of data from living populations and greater collaboration between bioarchaeologists and human biologists.

Longitudinal study of breastfeeding structure and women's work in the Brazilian Amazon

It is well established that breast milk is the ideal food for infants and that breastfeeding has short- and long-term health benefits for the mother and child. However, there is variation in breastfeeding patterns between populations. Womens work is thought to influence breastfeeding patterns and timing of supplementation and it is often assumed that women in subsistence-oriented societies can more easily integrate their productive and reproductive activities. This article reports longitudinal data, collected in three rounds (resguardo [<40 days], peak [2-4 months], and late [14-16 months] lactation), on breastfeeding structure, infant care, and work patterns of 17 rural Amazonian women in an effort to understand how breastfeeding structure and maternal time allocation changed over time, as well as the strategies women used to integrate their productive and reproductive roles. Women breastfed 10.6 ± 3.1, 9.4 ± 3.4, and 9.6 ± 5.5 times per 9-h period in the three rounds, respectively. Breastfeeding structure, specifically session duration, changed over time (P < 0.05). As lactation progressed, women spent less time breastfeeding and in infant care and more time in subsistence work. In peak lactation, subsistence work was negatively correlated with infant care (r = -0.4, P = 0.01), breastfeeding (r = -0.29, P = 0.05) and session duration (r = -0.39, P < 0.01) and in late lactation was negatively correlated with time spent breastfeeding (r = -0.39, P < 0.01) and in infant care (r = -0.50, P < 0.01) and positively correlated with inter-session interval (r = 0.40, P < 0.01). Generally, women reduced time in subsistence work when breastfeeding was more intense and returned to normal activity patterns once infants were being supplemented. The costs and benefits associated with womens strategies are discussed.

Conditional Cash Transfers, Food Security, and Health: Biocultural Insights for Poverty-Alleviation Policy from the Brazilian Amazon

Conditional cash transfer (CCT) programs have become an increasingly popular component of poverty-alleviation policies worldwide. The highly publicized success of Brazil’s Bolsa Família program (BFP), the largest such program in the world, has become a model for CCT programs elsewhere, including in highly rural African nations. This is despite the dearth of information on the impact of the program in rural contexts. Drawing on a unique natural experiment and using detailed anthropometric and dietary data collected in rural Amazonian subsistence-based communities, we analyze the impact of this critical policy on programmatic goals among the rural poor. Our data demonstrate the urgent need for more fine-grained biocultural research on this and similar policies. We show that despite close adherence to programmatic conditionalities, recipient households’ food security was measurably worse off and children’s poor nutritional status was virtually unchanged 4 years into the program. Using detailed ethnographic insights, we discuss the mechanisms that may explain these disappointing results in this rural zone and raise broader questions about the role of CCT programs for breaking the cycle of poverty in subsistence-based communities worldwide, especially without concomitant investment in public health and sanitation infrastructure.

The use of biocultural data in interpreting sex differences in body proportions among rural Amazonians

Variation in height and body proportions is relatively well-understood at the inter-population level, but less is known about intra-population variation. This study explores intra-population variation in body proportions among 172 (88 female; 84 male) adult rural Amazonians. We test the hypotheses that: (1) stunting is associated with changes in proportions and fatness; (2) the sexes express different proportions in response to similar environmental stress; and (3) female growth is negatively affected by the costs of reproduction. We examined height, sitting height, and total leg length in subsamples based on sex and nutritional status (stunted/nonstunted) in relation to biocultural factors including access to food and healthcare and female reproductive history parameters. Differences in proportions were examined using the Quick-Test (Tsutakawa and Hewett: Biometrics 33 (1977) 215-219); correlation analyses were used to detect associations between anthropometric data and body fatness, and female reproductive history parameters. We found significantly higher rates of stunting among females (X(2) = 5.31; P = 0.02; RR = 1.4). Stunted individuals exhibited relatively shorter legs than nonstunted individuals (P = 0.02), although this was not found in within-sex analyses. A significant negative correlation was found between leg length index and fatness (P < 0.01). Lastly, females exhibited relatively shorter legs than males (P = 0.0003) and, among females, height and leg length were significantly positively correlated with age-at-first-birth (P < 0.02) suggesting that adolescent pregnancy may negatively affect growth in this population. Our findings provide insights for the study of intra-population variation in body proportions and highlight the importance of biocultural data in interpreting the pattern of variation observed in living and past populations.