Human biology of poverty

Human biology of povert

The Maya Project: a mirror for human growth in biocultural perspective

Our purpose in this chapter is to explain how human physical growth reflects the biocultural environment in which groups of people live. We do this in the context of our research on the physical growth and health of Maya children and adults. The Maya are one of the native peoples of the Americas. There are an estimated 7-8 million Maya living in Guatemala, the Yucatan Peninsula and a few other areas of southern Mexico, Belize, El Salvador, and western Honduras (Figure 1.1). The majority, about 6.5 million live in the highlands of Guatemala (Bogin, 2012). These demographic statistics make the Maya the most populous Native American ethnic group. To better understand the Maya people we created the Maya Project, a blend of art and science portraying the biocultural realities of the Maya in Mesoamerica. One aspect of the Maya Project is a web site – http://mayaproject.org.uk. We will highlight some aspects of the Maya Project web site in later sections of this chapter. First we offer some explanation of the biocultural perspective of human growth

Leg length, body proportion, and health: a review with a note on beauty

Decomposing stature into its major components is proving to be a useful strategy to assess the antecedents of disease, morbidity and death in adulthood. Human leg length (femur + tibia), sitting height (trunk length + head length) and their proportions, for example, (leg length/stature), or the sitting height ratio (sitting height/stature × 100), among others) are associated with epidemiological risk for overweight (fatness), coronary heart disease, diabetes, liver dysfunction and certain cancers. There is also wide support for the use of relative leg length as an indicator of the quality of the environment for growth during infancy, childhood and the juvenile years of development. Human beings follow a cephalo-caudal gradient of growth, the pattern of growth common to all mammals. A special feature of the human pattern is that between birth and puberty the legs grow relatively faster than other post-cranial body segments. For groups of children and youth, short stature due to relatively short legs (i.e., a high sitting height ratio) is generally a marker of an adverse environment. The development of human body proportions is the product of environmental x genomic interactions, although few if any specific genes are known. The HOXd and the short stature homeobox-containing gene (SHOX) are genomic regions that may be relevant to human body proportions. For example, one of the SHOX related disorders is Turner syndrome. However, research with non-pathological populations indicates that the environment is a more powerful force influencing leg length and body proportions than genes. Leg length and proportion are important in the perception of human beauty, which is often considered a sign of health and fertility. © 2010 by the author

The Body Mass Index: the good, the bad, and the horrid

The Body Mass Index (BMI) was developed to estimate the risk for overweight in large samples of people from the wealthy, heavily industrialized nations of Western Europe and North America. When used for this purpose the BMI is, generally, a good tool to estimate overweight. The BMI is a bad tool when used to estimate fatness prior to the onset of the obesity epidemic in 1980 because BMI cannot distinguish between fat and lean tissue and there was, generally, lower levels of fatness in the general population before that date. The BMI is also a bad tool when used to estimate fatness for individuals in any nation or in any group of people. The BMI was never intended to be used for individual diagnosis. The BMI becomes a horrid tool to estimate fatness or health risk when used in some groups of people, such as high-level athletes, body building enthusiasts, people engaged in jobs with strenuous physical activity, and in groups suffering from the nutritional double-burden of very short stature with high body fatness

Associations between anthropometric indicators of adiposity and body fat percentage in normal weight young adults

The purpose of this cross-sectional study was to determine the associations between various anthropometric adiposity screening indices and body fat percentage estimated by bioelectrical impedance analysis (BIA). A total of 186 (95 male and 91 female) normal weight (body mass index [BMI] = 18.5-24.9 kg/m2) young adults (mean age= 20.96 ± 2.03 years) were measured on body fat percentage, body height, body mass, waist and hip circumferences. Abdominal volume index, body adiposity index, BMI, body roundness index, conicity index, reciprocal ponderal index, waist to height ratio, waist to height 0.5 ratio, and waist to hip ratio were calculated accordingly. Results revealed significant gender effects in all main anthropometric measurements. Except for waist to hip ratio, results indicated significant associations between anthropometric indices and BIA in both male and female participants. BIA results were found to be largely associated with BMI and abdominal volume index in both genders. BlandAltman analysis showed good agreements between these indices and BIA. Considerable associations and agreements highlight the potential importance and the use of several anthropometric proxies to estimate body adiposity among male and female non-overweight/obese young adults. Despite continuing discussion regarding its accuracy, BMI seems to be useful for monitoring body adiposity within this cohort

Logistics of using the Actiheart physical activity monitors in urban Mexico among 7- to 9-year-old children

Logistics of using new measurement devices are important to understand when developing protocols. This paper discusses the logistics of using Actiheart physical activity monitors on children in an urban, tropical environment in a developing country. Actiheart monitoring of 36 children aged 7-9 years old was undertaken for 7 days in the city of Mérida, Yucatán, Mexico. The Actiheart proved fragile for children and difficult to mend in the field. The excessive sweating due to the tropical climate caused poor adherence of the electrode pads, requiring a pad change midway through and extra pads to be provided. Also extra time was needed to be allotted for increased instructions to participants and their mothers and for individual calibration. When collecting objectively measured physical activity data under harsh conditions, the protocol must accommodate local conditions and device limitations and allow increased time with participants to obtain good quality data. © 2011 Wiley-Liss, Inc

Growing up in Portugal: Cape Verdean ancestry children exhibit low overweight and obesity compared to Portuguese in urban Lisbon

Portugal has one of the highest rates of childhood overweight and obesity (OW/OB) in Europe. However little is known about the health of ethnic minorities living in its capital city, Lisbon. The Cape Verdean community in Lisbon tend to have low educational levels, material deprivation and they struggle with discrimination and racism, factors that would likely be associated with a higher prevalence of OW/OB. Data for the Cape Verdean population were collected in three different time periods by three different research teams in 1993, 2009 and 2013 and included children from 6 to 12 years living in Cova da Moura neighbourhood, Great Lisbon Metro Area (GLMA). The Portuguese national survey was collected between 2009/2010 at public and private schools in mainland Portugal and included height, weight, skinfolds, arm, and waist circumferences. From these survey data body mass index (BMI) and the prevalence of stunting, (chronic malnutrition - low height-for-age) and underweight (low-weight-for-age) were calculated according to reference values proposed by Frisancho (2008). Overweight and obesity values were defined based on the references established by the International Obesity Task Force (IOTF). Results show that there are significant differences in height for boys and girls between Cape Verdean and Portuguese children. Generally, Cape Verdeans’ growth falls within the healthy range of International growth references across all of the survey data collected. Cape Verdean rates for combined overnutrition (overweight and obesity) in 2013 (9.8% for boys and 16.7% for girls) are lower than the Portuguese (33% for boys and 31.7% for girls). Logistic regression models showed that Cape Verdean children have a lower risk of being OW/OB when accounting for breastfeeding,birthweight,maternal education and occupation. Despite living in a deprived neighbourhood these Cape Verdean children seem to have grown more healthily than Portuguese ancestry children. The challenge for policy makers will be to support improvement of the poverty related living conditions of this community without creating a risky environment for increasing prevalence of overweight and obesity

Caesarean birth and adiposity parameters in 6‐to 8 year‐old urban Maya children from two cities of Yucatan, Mexico [Abstract]

Caesarean birth and adiposity parameters in 6‐to 8 year‐old urban Maya children from two cities of Yucatan, Mexico [Abstract

Fat free mass explains the relationship between stunting and energy expenditure in urban Mexican Maya children

Background: Childhood stunting has been associated with an increased risk of obesity in adulthood, but the causes are unclear. This study hypothesizes that stunting significantly reduces both resting and activity energy expenditure. Aim: To assess and describe energy expenditure of low socio-economic Maya children and to determine whether stunting is independently related to energy expenditure after controlling for lean mass. Subjects and methods: Thirty-three urban Maya children, 17 boys, aged 7–9 years, living in Merida, Mexico, were measured for height, weight and bioelectrical impedance analysis (BIA). Body composition was estimated from BIA. Energy expenditure was measured for one week using the Actiheart (combined heart rate and accelerometer). Results: Stunting (height-for-age below the 5th percentile of NHANES III based references) affected 35% of these physically active children. Using multiple linear regression analysis, greater lean body mass predicted higher resting and activity energy expenditure. Stature was not a significant predictor of resting energy expenditure. A lower height-for-age z-score, but not stunting as a categorical variable, significantly predicted lower activity energy expenditure. Conclusion: The hypothesis that stunting reduces total energy expenditure (resting + active) in children is not supported. Rather, children with shorter stature and less lean body mass have lower total energy expenditure. Complex interactions between body size, body composition, and metabolic activity appear to elevate the risk for later life obesity in these Maya children

Effects of stunting on body composition, biological age, and muscle strength of Maya and Ladino children in Guatemala [Abstract]

Effects of stunting on body composition, biological age, and muscle strength of Maya and Ladino children in Guatemala [Abstract