Nutritional anthropology in the world.

Nutritional anthropology is the study of human subsistence, diet and nutrition in comparative social and evolutionary perspective. Many factors influence the nutritional health and well-being of populations, including evolutionary, ecological, social, cultural and historical ones. Most usually, biocultural approaches are used in nutritional anthropology, incorporating methods and theory from social science as well as nutritional and evolutionary science. This review describes approaches used in the nutritional anthropology of past and present-day societies. Issues of concern for nutritional anthropology in the world now include: understanding how undernutrition and food insecurity are produced at local, regional and international levels; how food systems are constructed using social, biological and biocultural perspectives; and obesity from a biocultural viewpoint. By critiquing framings of present-day diet in an evolutionary context, nutritional anthropology asks 'what should be eaten?', rather than 'what can be eaten?', and 'how cheaply can people be fed?'.

Translating models of obesity to tackle common obesity.

Tackling common obesity rests on having models of obesity that can be effectively translated into models for intervention; are we nearly there yet?

Obesity and environments external to the body.

Studies of environment and obesity usually use epidemiologically tractable measures that are proxies for energy balance or macronutrient composition intake, mostly to identify individual behavioural changes for prevention or reduction of obesity, or inform policy. Of environments external to the body as they relate to obesity, the built environment and the food environment are considered among the most important. Incorporating human sociality into obesity and environments research enriches the field by offering possible ways for understanding obesity production via social stress, dietary preference, food consumption and physical activity. External environments are in flux, however, especially with changing urban form and social environmental hybridity since Web 2.0, with urban polycentricity and networked and online activity influencing obesity production in new ways. While the world's rural populations are experiencing the fastest increases in obesity, large urban populations benefit from scale in setting the physical conditions for physical activity and healthy food availability, with larger and polycentric cities having lower rates of obesity than smaller monocentric or dispersed cities. It is argued that built, food and social environments set the context for obesity production or its amelioration, with sociodemographic factors being more important than new phenomena such as digital and smart technologies. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.

Concealed pregnancy as an act of care? A qualitative analysis of motivations for concealing and non-disclosure of early pregnancy in The Gambia.

BACKGROUND: A barrier to achieving first trimester antenatal care (ANC) attendance in many countries has been the widespread cultural practice of not discussing pregnancies in the early stages. Motivations for concealing pregnancy bear further study, as the interventions necessary to encourage early ANC attendance may be more complicated than targeting infrastructural barriers to ANC attendance such as transportation, time, and cost. METHODS: Five focus groups with a total of 30 married, pregnant women were conducted to assess the feasibility of conducting a randomised controlled trial to evaluate the effectiveness of early initiation of physical activity and/or yoghurt consumption in reducing Gestational Diabetes Mellitus in pregnant women in The Gambia. Focus group transcripts were coded through a thematic analysis approach, assessing themes as they arose in relation to failure to attend early ANC. RESULTS: Two reasons for the concealment of pregnancies in the first trimester or ahead of a pregnancy's obvious visibility to others were given by focus group participants. These were 'pregnancy outside of marriage' and 'evil spirits and miscarriage.' Concealment on both grounds was motivated through specific worries and fears. In the case of a pregnancy outside of marriage, this was worry over social stigma and shame. Evil spirits were widely considered to be a cause of early miscarriage, and as such, women may choose to conceal their pregnancies in the early stages as a form of protection. CONCLUSION: Women's lived experiences of evil spirits have been under-explored in qualitative health research as they relate specifically to women's access to early antenatal care. Better understanding of how such sprits are experienced and why some women perceive themselves as vulnerable to related spiritual attacks may help healthcare workers or community health workers to identify in a timely manner the women most likely to fear such situations and spirits and subsequently conceal their pregnancies.

The social origins of obesity within and across generations.

We propose a model for obesity development that traces a considerable part of its origins to the social domain (mainly different forms of prolonged social adversity), both within and across generations, working in tandem with a genetic predisposition. To facilitate overview of social pathways, we place particular focus on three areas that form a cascading sequence: (A) social adversity within the family (parents having a low education, a low social position, poverty and financial insecurity; offspring being exposed to gestational stress, unmet social and emotional needs, abuse, maltreatment and other negative life events, social deprivation and relationship discord); (B) increasing levels of insecurity, negative emotions, chronic stress, and a disruption of energy homeostasis; and (C) weight gain and obesity, eliciting further social stress and weight stigma in both generations. Social adversity, when combined with genetic predisposition, thereby substantially contributes to highly effective transmission of obesity from parents to offspring, as well as to obesity development within current generations. Prevention efforts may benefit from mitigating multiple types of social adversity in individuals, families, and communities, notably poverty and financial strain, and by improving education levels.

How active can preschoolers be at home? Parents' and grandparents' perceptions of children's day-to-day activity, with implications for physical activity policy.

BACKGROUND: The importance of physical activity in early childhood for establishing long-term health is well understood, yet with the exception of recent WHO guidelines, public health initiatives rarely focus on children below school age. Moreover, little is known about how domestic spaces and day-to-day caring activities influence preschool-age children's physical activity. To examine this, we explore caregivers' perceptions of young children's activities within and outside the home, and we consider how lived experiences of caregiving align (or not) with current physical activity policy. METHODS: Semi-structured interviews with 49 parents and grandparents from 16 families were conducted in Oregon, USA; each family had a child aged 3-5 years. Questions focused on caregivers' perceptions of and involvement with children's body weights, activities, and food practices. The interviews were analysed using thematic analysis. Our analysis drew on a materialities framework, attending to relationships between children, caregivers, spaces in and around the home, and everyday activities. RESULTS: Four themes were developed: appropriateness of outside versus inside spaces for physical activity; making accommodations for physical activity in the home; active spaces of care, referring to relationships among space, activity type, and caregiver attention; and mundane movement, or the low-intensity movement of everyday life. Together, the results highlight that children's day-to-day activities cut across a spectrum of movement, mediated by available spaces and caregiving affordances. CONCLUSIONS: Attending to the full spectrum of children's movements highlights how children's activities interlink with family routines, available indoor and outdoor spaces, and the intended uses of these spaces. These interplays between space, care, and physical activity enacted at the household level should inform an integrated, systems-level public health approach to increasing health and well-being for preschool-age children. Suggestions for improvement include coordinating policy development across multiple fields (e.g., housing design, urban planning) that structure the activities of children and their caregivers across 'home' and 'outside' spaces.

Pregnancy-related interventions in mothers at risk for gestational diabetes in Asian India and low and middle-income countries (PRIMORDIAL study): protocol for a randomised controlled trial.

INTRODUCTION: Lifestyle modification is the mainstay of gestational diabetes mellitus (GDM) prevention. However, clinical trials evaluating the safety and efficacy of diet or physical activity (PA) in low-income and middle-income settings such as Africa and India are lacking. This trial aims to evaluate the efficacy of yoghurt consumption and increased PA (daily walking) in reducing GDM incidence in high-risk pregnant women. METHODS AND ANALYSIS: The study is a 2×2 factorial, open-labelled, multicentre randomised controlled trial to be conducted in Vellore, South India and The Gambia, West Africa. 'High-risk' pregnant women (n=1856) aged ≥18 years and ≤16 weeks of gestational age, with at least one risk factor for developing GDM, will be randomised to either (1) yoghurt (2) PA (3) yoghurt +PA or (4) standard antenatal care. Participants will be followed until 32 weeks of gestation with total active intervention lasting for a minimum of 16 weeks. The primary endpoint is GDM incidence at 26-28 weeks diagnosed using International Association of the Diabetes and Pregnancy Study Groups criteria or elevated fasting glucose (≥5.1 mmol/L) at 32 weeks. Secondary endpoints include absolute values of fasting plasma glucose concentration at 32 weeks gestation, maternal blood pressure, gestational weight gain, intrapartum and neonatal outcomes. Analysis will be both by intention to treat and per-protocol. Continuous outcome measurements will be analysed using multiple linear regression and binary variables by logistic regression. ETHICS AND DISSEMINATION: The study is approved by Oxford Tropical Research Ethics Committee (44-18), ethics committees of the Christian Medical College, Vellore (IRB 11367) and MRCG Scientific Coordinating Committee (SCC 1645) and The Gambia Government/MRCG joint ethics committee (L2020.E15). Findings of the study will be published in peer-reviewed scientific journals and presented in conferences. TRIAL REGISTRATION NUMBER: ISRCTN18467720.

Ecological Sensing Through Taste and Chemosensation Mediates Inflammation: A Biological Anthropological Approach.

Ecological sensing and inflammation have evolved to ensure optima between organism survival and reproductive success in different and changing environments. At the molecular level, ecological sensing consists of many types of receptors located in different tissues that orchestrate integrated responses (immune, neuroendocrine systems) to external and internal stimuli. This review describes emerging data on taste and chemosensory receptors, proposing them as broad ecological sensors and providing evidence that taste perception is shaped not only according to sense epitopes from nutrients but also in response to highly diverse external and internal stimuli. We apply a biological anthropological approach to examine how ecological sensing has been shaped by these stimuli through human evolution for complex interkingdom communication between a host and pathological and symbiotic bacteria, focusing on population-specific genetic diversity. We then focus on how these sensory receptors play a major role in inflammatory processes that form the basis of many modern common metabolic diseases such as obesity, type 2 diabetes, and aging. The impacts of human niche construction and cultural evolution in shaping environments are described with emphasis on consequent biological responsiveness.

How does psychosocial stress affect the relationship between socioeconomic disadvantage and overweight and obesity? Examining Hemmingsson's model with data from a Danish longitudinal study.

BACKGROUND: Chronic stress in childhood may increase the risk of overweight and obesity in young people. Erik Hemmingsson has suggested a new obesity causation model which focuses on psychosocial stress. The aim was to examine the associations between socioeconomic disadvantage and overweight and obesity and examine if these associations attenuate, when the effect of the different domains from Eric Hemmingsson's obesity causation model were taken into account. METHODS: A longitudinal study using data from The West Jutland Cohort Study (N = 2879). Outcome was overweight and obesity combined derived from self-reported weight and height at age 15, 18, 21 and 28 years. Exposure variables were equivalised household income, educational level and labour market participation of the mother derived from registers and psychosocial variables derived from questionnaires. A three-step adjustment model using logistic regression and stratified by gender was applied. RESULTS: Mother's low educational level was associated with a 3-fold increased odds of obesity in 18 year-old-girls, which attenuated when adjusting for the domains adult distress, disharmonious family environment and offspring distress. In 28 year-old girls, a 2.5-fold increased odds of obesity was observed, which attenuated when mutual adjusted for other socioeconomic variables and attenuated even further when adjusting for all the domains. In 18-year-old boys, a 3-fold increased odds of obesity was observed which attenuated after adjustments for adult distress, disharmonious family environment and offspring distress. In 21-year old boys, a four-fold increased odds of obesity was observed that attenuated after adjustments. At age 28 years, a three-fold increased odds of obesity was observed, which vanished in the fully adjusted model. CONCLUSIONS: Our study confirms to some extent that the associations between socioeconomic disadvantage and overweight and obesity can be explained by the domains included in Erik Hemmingsson's model, although our results should be interpreted with caution. Adult distress, disharmonious family environment and offspring distress accounted for some of the association in girls, whereas in boys it was primarily offspring distress, which had the greatest impact. Young people's educational attainment can act as a buffer in the relationship between mother's lower educational level and obesity at age 28 years.

Identifying notions of environment in obesity research using a mixed-methods approach.

The recent rise of computation-based methods in social science has opened new opportunities for exploring qualitative questions through analysis of large amounts of text. This article uses a mixed-methods design that incorporates machine reading, network analysis, semantic analysis, and qualitative analysis of 414 highly cited publications on obesogenic environments between 2001 and 2015. The method produces an elaborate network map exhibiting five distinct notions of environment, all of which are currently active in the field of obesity research. The five notions are institutional, built, food, family, and bodily environments. The network map is proposed as a navigational tool both for policy actors who wish to coordinate efforts between a variety of stakeholders and for researchers who wish to understand their own research and research plans in light of different positions in the field. The final part of the article explores how the network map may also initiate a broader set of reflections on the configuration, differentiation, and coherence of the field of obesity research.

The 'who' and 'what' of #diabetes on Twitter.

Social media are being increasingly used for health promotion, yet the landscape of users, messages and interactions in such fora is poorly understood. Studies of social media and diabetes have focused mostly on patients, or public agencies addressing it, but have not looked broadly at all of the participants or the diversity of content they contribute. We study Twitter conversations about diabetes through the systematic analysis of 2.5 million tweets collected over 8 months and the interactions between their authors. We address three questions. (1) What themes arise in these tweets? (2) Who are the most influential users? (3) Which type of users contribute to which themes? We answer these questions using a mixed-methods approach, integrating techniques from anthropology, network science and information retrieval such as thematic coding, temporal network analysis and community and topic detection. Diabetes-related tweets fall within broad thematic groups: health information, news, social interaction and commercial. At the same time, humorous messages and references to popular culture appear consistently, more than any other type of tweet. We classify authors according to their temporal 'hub' and 'authority' scores. Whereas the hub landscape is diffuse and fluid over time, top authorities are highly persistent across time and comprise bloggers, advocacy groups and NGOs related to diabetes, as well as for-profit entities without specific diabetes expertise. Top authorities fall into seven interest communities as derived from their Twitter follower network. Our findings have implications for public health professionals and policy makers who seek to use social media as an engagement tool and to inform policy design.

Framing obesity in UK policy from the Blair years, 1997-2015: the persistence of individualistic approaches despite overwhelming evidence of societal and economic factors, and the need for collective responsibility.

Since 1997, and despite several political changes, obesity policy in the UK has overwhelmingly framed obesity as a problem of individual responsibility. Reports, policies and interventions have emphasized that it is the responsibility of individual consumers to make personal changes to reduce obesity. The Foresight Report 'Tackling Obesities: Future Choices' (2007) attempted to reframe obesity as a complex problem that required multiple sites of intervention well beyond the range of personal responsibility. This framing formed the basis for policy and coincided with increasing acknowledgement of the complex nature of obesity in obesity research. Yet policy and interventions developed following Foresight, such as the Change4Life social marketing campaign, targeted individual consumer behaviour. With the Conservative-Liberal Democrat government of 2011, intervention shifted to corporate and individual responsibility, making corporations voluntarily responsible for motivating individual consumers to change. This article examines shifts in the framing of obesity from a problem of individual responsibility, towards collective responsibility, and back to the individual in UK government reports, policies and interventions between 1997 and 2015. We show that UK obesity policies reflect the landscape of policymakers, advisors, political pressures and values, as much as, if not more than, the landscape of evidence. The view that the individual should be the central site for obesity prevention and intervention has remained central to the political framing of population-level obesity, despite strong evidence contrary to this. Power dynamics in obesity governance processes have remained unchallenged by the UK government, and individualistic framing of obesity policy continues to offer the path of least resistance.

Obesity emergence in the Pacific islands: why understanding colonial history and social change is important.

OBJECTIVE: Between 1980 and 2008, two Pacific island nations - Nauru and the Cook Islands - experienced the fastest rates of increasing BMI in the world. Rates were over four times higher than the mean global BMI increase. The aim of the present paper is to examine why these populations have been so prone to obesity increases in recent times. DESIGN: Three explanatory frames that apply to both countries are presented: (i) geographic isolation and genetic predisposition; (ii) small population and low food production capacity; and (iii) social change under colonial influence. These are compared with social changes documented by anthropologists during the colonial and post-colonial periods. SETTING: Nauru and the Cook Islands. RESULTS: While islands are isolated, islanders are interconnected. Similarly, islands are small, but land use is socially determined. While obesity affects individuals, islanders are interdependent. New social values, which were rapidly propagated through institutions such as the colonial system of education and the cash economy, are today reflected in all aspects of islander life, including diet. Such historical social changes may predispose societies to obesity. CONCLUSIONS: Colonial processes may have put in place the conditions for subsequent rapidly escalating obesity. Of the three frameworks discussed, social change under colonial influence is not immutable to further change in the future and could take place rapidly. In theorising obesity emergence in the Pacific islands, there is a need to incorporate the idea of obesity being a product of interdependence and interconnectedness, rather than independence and individual choice.

Do adult obesity rates in England vary by insecurity as well as by inequality? An ecological cross-sectional study.

OBJECTIVE: Geographical variations in adult obesity rates have been attributed in part to variations in social and economic inequalities. Insecurity is associated with obesity at the cross-national level, but there is little empirical evidence to show that insecurity contributes to the structuring of adult obesity rates at the subnational level. This is examined in this study across local authorities in England, using a recently developed social classification for the British population. SETTING: Modelled obesity rates from the Health Survey for England 2006-2008 were related to social class (as estimated from the BBC's Great British Class Survey of 2011 and a nationally representative sample survey), across 320 local authorities in England. PRIMARY AND SECONDARY OUTCOME MEASURES: Comparisons of mean obesity rates across Z score categories for seven latent social classes were carried out using one-way analysis of variance. Pooled ordinary least square regression analyses of obesity rates by local authorities according to the proportion of different social classes within each of them were performed to determine the extent of geographical variations in obesity rates among the classes that were more greatly based on insecurity (emergent service workers, precariat), and those more closely based on inequality (elite, established middle class, technical middle class, new affluent workers, traditional working class). RESULTS: Adult obesity rates vary negatively across local authorities according to the proportion of people in the elite (F=39.06, p<0.001) and technical middle class (F=8.10, p<0.001) and positively with respect to the proportion of people of the established middle class (F=26.36, p<0.001), new affluent workers (F=73.03, p<0.001), traditional working class (F=23.00, p<0.001) and precariat (F=13.13, p<0.001). Social classes more closely based on inequality show greater association with adult obesity rates across local authorities than social classes more closely based on insecurity. CONCLUSIONS: Both insecurity and inequality are associated with the geographical patterning of adult obesity rates across England.

Variation in height and BMI of adult Indians.

It is well known that height and weight are interrelated, and that both are related to socioeconomic variables. The objective of this study was to assess the effect of socioeconomic variables on the heights and weights of different groups of people, formed according to different levels of heights and weights, and to see whether there are sex differences in the variations in heights and weights. Data for adults aged 15-49 years were taken from the India National Family Health Survey-3 and descriptive studies and multiple linear regression analyses carried out. A clear positive association was found for height and BMI with economic level (except for overweight females in the case of BMI). In the case of BMI, it is age that seems to be the most influential factor. Surprisingly, the observed changes in height and BMI are not as expected for short and tall or underweight and overweight people; these sometimes behave in the opposite directions to that of normal height and weight people. The basic assumption of multivariate normality is not valid due to changing relations at different height and BMI levels.