Abstract

Considered an important public health problem among Indigenous peoples in Brazil, obesity is a risk factor for Noncommunicable Diseases (NCDs) and conditions. The present study aimed to describe the occurrence of excess weight, obesity, and associated factors in Xavante Indigenous adults, through a nutritional survey carried out in the population ≥ 15 years of age living in the Pimentel Barbosa and Wedezé Indigenous Lands, Mato Grosso, Central Brazil, during the period of June to August 2011. Eight of the 10 villages in the territory were investigated. Anthropometric, bioimpedance and socioeconomic data were collected. This study counted on 495 participants, corresponding to 94.1% of the target population. The prevalence of overweight and obesity was 65.9% (male: 63.2%; female: 68.6%) and 19.8% (male: 21.3%; female: 18.2%), respectively. In the multiple regression model, the prevalence of excess weight was higher among women, in higher age groups and education levels, in individuals living in group 2 of the villages, and in households with low consumption of farmed foods. An increase in the age group aged 20 to 49 years and in individuals living in households with a low consumption of food from hunting, fishing, and gathering presented the highest prevalence of obesity.

Key words:
Health of Indigenous peoples; Obesity; Epidemiology; Xavante

Introduction

In recent decades, changes in health standards of populations have been reported globally, defined by an expressive increase in Noncommunicable Diseases (NCDs) and their risk factors. To a great extent, these changes can be attributed to the processes of industrialization and urbanization, to population aging, to changes in behavior, as well as in means of subsistence. Such changes appear in various manners, and it is common to find, in developing countries and among populations in unfavorable economic conditions, the presence of a double burden of disease, defined by the persistence of infectious, parasitic, and deficiency diseases, along with the emergence of NCDs¹1 Omran AR. The epidemiologic transition: a theory of the epidemiology of population change. Milbank Q 2005; 83(4):731-757.^,22 Popkin BM, Adair LS, Ng SW. Global nutrition transition and the pandemic of obesity in developing countries. Nutr Rev 2012; 70(1):3-21.. Among these NCDs, excess weight and obesity emerge as important public health issues, since they are considered to be risk factors for other types of NCDs, such as diabetes, hypertension, and some kinds of cancer³3 Calle EE, Kaaks R. Overweight, obesity and cancer: epidemiological evidence and proposed mechanisms. Nat Rev Cancer 2004; 4(8):579-591.

4 Powell-Wiley TM, Poirier P, Burke LE, Després JP, Gordon-Larsen P, Lavie CJ, Lear SA , Ndumele CE, Neeland IJ, Sanders P, St-Onge MP, American Heart Association Council on Lifestyle and Cardiometabolic Health; Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; Council on Epidemiology and Prevention; and Stroke Council. Obesity and cardiovascular disease: a scientific statement from the American Heart Association. Circulation 2021; 143(21):e984-e1010.^-55 Savva SC, Lamnisos D, Kafatos AG. Predicting cardiometabolic risk: waist-to-height ratio or BMI. A meta-analysis. Diabetes Metab Syndr Obes 2013; 6:403-419..

In Brazil, studies show evidence of disparity in the distribution of excess weight, obesity, and other NCDs, something that has been associated with markers of social inequality, such as income, education, race, and ethnicity, for instance⁶6 Monteiro CA, D'A Benicio MH, Conde WL, Popkin BM. Shifting obesity trends in Brazil. Eur J Clin Nutr 2000; 54(4):342-346.. Among Indigenous populations, both in Brazil and internationally, excess weight and obesity are emerging illnesses. Such a profile is characterized by the history of contact of Indigenous peoples with the surrounding society, as well as by intrusion and loss of land, and is related to changes in the means of subsistence, together with dependency on the regional market⁷7 Coimbra Jr CEA, Tavares FG, Ferreira AA, Welch JR, Horta BL, Cardoso AM, Santos RV. Socioeconomic determinants of excess weight and obesity among Indigenous women: findings from the First National Survey of Indigenous People's Health and Nutrition in Brazil. Public Health Nutr 2021; 24(7):1941-1951.

8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002.

9 Lourenco AEP, Santos RV, Orellana JDY, Coimbra CEAJ. Nutrition transition in Amazonia: obesity and socioeconomic change in the Surui Indians from Brazil. Am J Hum Biol 2008; 20(5):564-571.

10 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.

11 Santos RV, Welch JR, Pontes AL, Garnelo L, Moreira Cardoso A, Coimbra Jr CEA. Health of Indigenous peoples in Brazil: inequities and the uneven trajectory of public policies. In: Oxford Research Encyclopedia of Global Public Health. Oxford: Oxford University Press; 2022. p. 1-33.^-1212 Cardoso AM, Tavares IN, Werneck GL. Indigenous health in Brazil: from vulnerable to protagonists. Lancet 2022; 400(10368):2011-2014..

The impact of this interaction appears as changes in the lifestyle of Indigenous populations, such as modifications in food consumption patterns, an increase in the intake of ultra-processed foods that are rich in sodium, and a decrease in the practice of physical activities. Nationally, such patterns were documented in the First National Health and Nutrition Survey of Indigenous Peoples (1st NHNSIP), which estimated a prevalences of 46.2% for excess weight and 15.8% for obesity among Indigenous women of reproductive age, with considerable regional inequalities⁷7 Coimbra Jr CEA, Tavares FG, Ferreira AA, Welch JR, Horta BL, Cardoso AM, Santos RV. Socioeconomic determinants of excess weight and obesity among Indigenous women: findings from the First National Survey of Indigenous People's Health and Nutrition in Brazil. Public Health Nutr 2021; 24(7):1941-1951., given that the highest prevalence was found in the Midwest region (excess weight: 52.8%; obesity: 17.2%) and South/Southeast (excess weight: 54.7%; obesity: 22.6%), while the lowest prevalence was found in the North region (excess weight: 31.2%; obesity: 6.1%)⁷7 Coimbra Jr CEA, Tavares FG, Ferreira AA, Welch JR, Horta BL, Cardoso AM, Santos RV. Socioeconomic determinants of excess weight and obesity among Indigenous women: findings from the First National Survey of Indigenous People's Health and Nutrition in Brazil. Public Health Nutr 2021; 24(7):1941-1951.. Several studies conducted in specific Indigenous communities reinforce the existence of a high prevalence of excess weight and obesity in Indigenous populations throughout the country¹⁰10 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.^,1313 Baldoni NR, Aquino JA, Alves GCS, Sartorelli DS, Franco LJ, Madeira SP, Dal Fabbro AL. Prevalence of overweight and obesity in the adult indigenous population in Brazil: a systematic review with meta-analysis. Diabetes Metab Syndr 2019; 13(3):1705-1715.

14 Fávaro TR, Ferreira AA, Cunha GM, Coimbra CEA. Excess weight in Xukuru indigenous children in Ororubá, Pernambuco State, Brazil: magnitude and associated factors. Cad Saude Publica 2019; 35 (Suppl. 3):e00056619.^-1515 Fávaro TR, Santos RV, Cunha GM, Leite IC, Coimbra Jr CEA. Obesidade e excesso de peso em adultos indígenas Xukuru do Ororubá, Pernambuco, Brasil: magnitude, fatores socioeconômicos e demográficos associados. Cad Saude Publica 2015; 31(8):1685-1697..

The Xavante people, inhabiting areas of the state of Mato Grosso, in the Midwest region of Brazil, is one of the Indigenous populations in which studies have indicated the health effects caused by the invasion of their land by the demographic frontier since the middle of last century. Studies that indicated those transformations also verified an increase in NCDs⁸8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002.^,1010 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.^,1616 Carneiro O, Jardim PC. Blood pressure in a Xavante tribe. Comparison after 15 years. Arq Bras Cardiol 1993; 61(5):279-282.

17 Dal Fabbro AL, Franco LJ, Silva AS, Sartorelli DS, Soares LP, Franco LF, Kuhn PC, Moisés RS, Vieira-Filho JPB. High prevalence of type 2 diabetes mellitus in Xavante Indians from Mato Grosso, Brazil. Ethn Dis 2014; 24(1):35-40.^-1818 Welch JR, Ferreira AA, Tavares FG, Lucena JRM, Gomes de Oliveira MV, Santos RV, Coimbra Jr CEA. The Xavante Longitudinal Health Study in Brazil: objectives, design, and key results. Am J Hum Biol 2019; 32(2):e23339.. Considering the context of changes in health standards of the Xavante people, the present study investigated the prevalence of excess weight and obesity among individuals aged 15 years and older, who reside in the Indigenous lands of Pimentel Barbosa and Wedezé. This study also provides evidence of specific socioeconomic and demographic factors associated with these populations.

Population and methodology

This study is part of an inquiry about health and nutritional conditions conducted with the Xavante population of the Indigenous Lands (IL) of Pimentel Barbosa and Wedezé, in the state of Mato Grosso, Central Brazil, which took place from June to August 2011. The present analysis focused on the population segment of ≥ 15 years of age, residing in eight of the ten eligible villages - Pimentel Barbosa, Eténhiritipá, Caçula, Wedezé, Asereré, Canoa, Reata, and Tanguro, which have 82.4% of the population of the IL studied. The community leaders of two of the villages did not accept the participation of their communities in the inquiry.

The sample began with 559 Indigenous individuals in the age group considered for the study. Among those, 33 women (7.8%) were pregnant or were unsure if they were pregnant, and were therefore excluded from the analyses. That resulted in a final contingent of 526 individuals who met the study’s inclusion criteria.

The team of field researchers had professionals in nursing, nutrition, and anthropology, trained and enabled to apply the questionnaire and to handle the instruments of the inquiry. The questionnaires were based on those used by the NHNSIP¹⁹19 Coimbra Jr CEA, Santos RV, Welch JR, Cardoso AM, Souza MC, Garnelo L, Rassi E, Follér ML, Horta BL. The First National Survey of Indigenous People's Health and Nutrition in Brazil: rationale, methodology, and overview of results. BMC Public Health 2013; 13:52., adapted for the cultural specificities of the Xavante and complemented by additional issues of interest, such as oral health. To do so, home interviews were conducted with heads of family or other adult representatives of the family, discussing the conditions of sanitation and housing, manners of food acquisition, and socioeconomic profile. The individual interviews covered education level, reproductive and health history, access to healthcare services, and current state of health. Anthropometric measurements of blood pressure, casual blood glucose and hemoglobin level were also taken.

Anthropometric and socioeconomic data

Height was measured in an erect position, with a portable Seca anthropometer, model 216 (Hamburg, Germany), and registered with 0.1 cm precision. Body weight was measured with a portable Seca digital scale, model 770 (Hamburg, Germany), with a maximum capacity of 150 kg and 100 g precision. Both measures, height and weight, were taken of all of the participants that were physically able, according to the recommendations by Lohman et al.²⁰20 Lohman TG, Roche AF, Martorell R. Anthropometric standartization reference manual. Champaign: Human Kinetics Books; 1988. To conduct the anthropometric measurements, the participants were asked to wear light clothes and to be barefoot.

The body mass index (BMI) was calculated based on the weight and height variables, by the formula weight/height²2 Popkin BM, Adair LS, Ng SW. Global nutrition transition and the pandemic of obesity in developing countries. Nutr Rev 2012; 70(1):3-21., and the cutoff points for normal weight, overweight, and obesity followed the guidelines set forth by the World Health Organization²¹21 World Health Organization (WHO). Obesity: preventing and managing the global epidemic - Report of a WHO consultation. World Health Organ Tech Rep Ser 2000; 894:i-xii, 1-253.. For the participants aged 14 to 19 years, the study adopted the cutoff points proposed by Onis²²22 Onis M, Onyango AW, Borghi E, Siyam A, Nishida C, Siekmann J. Development of a WHO growth reference for school-aged children and adolescents. Bull World Health Organ 2007; 85(9):660-667..

Socioeconomic indicators

The following demographic and socioeconomic indicators were used: sex, age (age group), household per capita income (calculated by dividing the total income by the number of residents in the household), education, owned household goods, and food consumption.

Education was measured in years of study, completed with approval, distributed in the following manner; Unschooled (never attended school), 1 to 8 years of Primary school, 1 to 3 years of High School and/or 1 to 5 periods in the Haiyô project (training of Indigenous teachers in High School - a partnership between the State Secretary of Education, the National Foundation for Indigenous peoples (FUNAI), and the National Health Foundation (Fundação Nacional de Saúde - FUNASA). However, the periods considered in that project were calculated with the equivalence of two periods of the Haiyô project, for one year of High School, since each period in the project lasts an average of 2 to 3 months. For analysis purposes, we used the indicator in a categorized manner (unschooled, 1st to 4th grade, 5th to 8th grade, and High School/Haiyô).

The indicator of owned goods (household goods) was calculated based on a report of durable goods present in the household, according to a list of goods based on previous studies¹⁰10 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.. The main components analysis was conducted with 20 goods in order to obtain an index of owned goods capable of discriminating the purchasing power of the families²³23 Vyas S, Kumaranayake L. Constructing socio-economic status indices: how to use principal components analysis. Health Policy Plan 2006; 21(6):459-468.. The values in the matrix, of the correlations between the variables, range from -0.133, for the correlation between car and gas stove, up to 0.896, for the correlation between television and DVD player. The Kaiser-Meyer-Olkin score reached 0.644, exceeding the minimum value of 0.60 recommended for the conduction of this type of analysis. The eingenvalue of the first component in the multivariate analysis was 4.316, representing 21.6% of the total variability of the data set. The second component had an eingenvalue of 54.0% lower than the first (11.8% of the total variability).

The items which stood out in the first component were television, DVD, parabolic antenna, digital cameras, generator, and loudspeakers. Only this component was used in the definition of socioeconomic indicator, because it showed more power of explanation of variability. The value of the index of owned goods for each family is the result of the sum of the contribution of each item (generated by the main components analysis) multiplied by the quantity of such goods present in the household. Next, the indicator was divided in tertiles, based on the distribution of the values among the households, resulting in the levels that were considered to classify each household as low, medium, or high. The values of this indicator ranged between -1.084 and 4.417 and had, as cutoff points, the values of -0.683 and 0.302, respectively.

The variable number of residents in the household was used as a characteristic of the household, classified in three categories: 1 to 9 residents, 10 to 19 residents, and 20 to 28 residents, given that 28 was the highest number found.

Household food consumption pattern

To estimate food consumption in the households, the study investigated frequency of consumption of foods acquired through the following categories of production: domestic agricultural and livestock farming; gathering, fishing and hunting; and goods purchased in a town. For each of the categories, the residents of the household were asked about their typical frequency of consumption throughout the year. This variable was used to characterize the economic insertion of the household in terms of the source of the food, and did not focus on the quantification of food consumption or individual nutrition. The foods detailed in the instrument contemplated all of the foods and food categories typically consumed by the Xavante from the villages that were part of the study. The instrument included 15 items from agriculture and livestock farming, such as wild rice, Xavante corn, etc., and 17 industrialized foods acquired by purchase, such as industrialized rice, coffee, sugar, cooking oil, among others. For each of the foods, the participants were asked about the frequency of consumption in the household, and the answers were classified as “never or rarely”, “only sometimes or only at specific times”, and “frequently or every day”. The main components analysis was conducted with each one of these groups of food frequency, which were denominated as “agriculture or livestock farming”, “hunting or gathering”, and “purchasing”.

The variable “group of villages” categorizes the participating villages in three groups, considering their territorial history, according to criteria proposed by Arantes et al.²⁴24 Arantes R, Welch JR, Tavares FG, Ferreira AA, Vettore MV, Coimbra CEA. Human ecological and social determinants of dental caries among the Xavante Indigenous people in Central Brazil. PLoS One 2018; 13(12):e0208312.. The first group included the villages of Pimentel Barbosa and Etênhiritipá, founded in 1970 and 2006, respectively. This group was more isolated and located in an area of preserved Cerrado. The second group was formed by the Caçula village, originated from the Pimentel Barbosa village in the 1980’s, and two small villages, originated from the Caçula village in the early 2000s (Canoa and Wedezé). This group inhabited a flooded area next to the Mortes river. The third group had the villages of Tanguro, separated from Pimentel Barbosa in the 1980’s, and two small villages originated from Tanguru in the early 2000s (Asereré and Reata). This group was located near a town, an interstate highway, and farms. To preserve confidentiality, we did not provide specific results for individual villages.

Statistical analysis

The descriptive analysis was conducted by the calculation of averages, of standard deviation, minimum and maximum values for anthropometric variables, socioeconomic scores, food consumption scores, and according to age group, sex, and group of villages. To evaluate the difference between proportions, the chi-square test was conducted. To verify differences in the averages of the anthropometric variables between sexes, the Student’s t test was used.

The correlation between variables was analyzed by means of the Pearson correlation coefficient in bivariate analyses, testing the statistical significance by using the two-tailed test. We also calculated the prevalence of excess weight and obesity, according to sex, age, and socioeconomic stratum and according to indicators of BMI.

Next, we analyzed the measures of association between each variable of interest and the excess weight and obesity outcomes, by means of crude prevalence, considering a 95% confidence interval (95%CI). Chi-square tests for linear trends were conducted to evaluate the differences between the proportions and between categories of the variables of interest. The prevalence of excess weight and of obesity was calculated by groups of villages, sex, age group, number of residents in the household, owned household goods, and frequencies of household food consumption.

The multivariate analysis followed a logistic regression with robust variance adjustment for dichotomous outcomes (yes and no) for excess weight and obesity. The initial step in the analysis was to select variables for inclusion in the multivariate regression. For that purpose, univariate regression was conducted for each investigated variable separately with one of the dependent variables (excess weight or obesity), considering a p-value of 0.20 for the selection of variables to be included in the following phase. Next, all of the variables selected in the previous phase were included in the multivariate logistic regression, once again selecting those that remained with a level of statistical significance p < 0.20 by mutual adjustment. The variables selected in the previous phase were part of the procedure of logistic regression, by using the stepwise backward method for selection of variables in the final model, maintaining only those with adjusted OR and respective 95%CI with a significance level of a p < 0.05.

The statistical analyses were conducted using the IBM SPSS Statistics for Windows program, version 20.0. (Armonk, NY, USA).

Ethical considerations

The study conducted with the Xavante population followed all of the norms for research established by the Declaration of Helsinki and by the International Ethical Directives from the CIOMS. The protocol of the study was approved by the research ethic committee of the Escola Nacional de Saúde Pública and by the National Research Ethics commission (protocol no. 2500202987/2010-14). The National Indigenous Foundation (Fundação Nacional do Índio - FUNAI) granted permission to conduct field research in federal Indigenous lands. All of the participants or their guardians were allowed to withdraw from participation at any moment. The analyses presented here are part of the doctoral dissertation of the main author of the article (FGT).

Results

Of the 526 Indigenous individuals eligible for this study, 31 were absent from the villages when measures were taken for weight and height. Therefore, our analysis was based on data from 495 individuals (Male: 253, 51.1%; Female: 242, 48.9%), corresponding to 94.1% of the population ≥ 15 years of age and of both sexes.

Table 1 presents the descriptive statistics of the anthropometric variables and socioeconomic indicators. The average age of the population was 34.3 years (SD:18.8), being 33.1 years (SD:18.1) for men and 35.5 years (SD:19.5) for women, with no significant statistical difference between the sexes. The weight and height averages presented statistical significance for the t test of difference in averages between the sexes, showing higher weight and height for men.

Among the villages that participated in the study, those with the highest number of individuals were Pimentel Barbosa (30.5%), Etênhiritipá (26.1%), and Caçula (21.0%). A higher proportion of female individuals was found in the unschooled stratum (39.3%) and in the 1^st to 4^th grade stratum (36.,0%), meanwhile the frequency of males is higher in the stratum with an education level of 5th to 8th grade (50.0%). In relation to household per capita income, most individuals earned between R$ 55.00 and R$ 109.99 (45.9%), with similar values for both sexes (Table 2).

Table 3 presents the prevalence of excess weight and of obesity according to socio-demographic and economic variables. There are statistically significant differences in the prevalence of excess weight between the categories of age group and frequency of consumption of foods produced by hunting/gathering and agriculture and livestock farming, given that the prevalence was higher for the intermediate age group and for the lower levels of food consumption in these standards. There were statistically significant differences in the prevalence of obesity among the categories of the variables of age group, education, owned household goods and frequency of consumption of foods from hunting/gathering, with a higher prevalence found in the intermediate age group, in the higher levels of education, in the higher levels of owned household goods, and in the low level of consumption of foods from hunting/gathering.

In the final multiple regression model, excess weight remained associated, with statistical significance, with sex, group of villages, age group, education, and agriculture/livestock farming. The chances of being excess weight were 63% higher among women when compared to men. The age groups 20 to 49 years and 50 years of age and older had 4.9-fold and 2.7-fold higher chances of being excess weight, when compared to the age group of 15 to 19 years. The categories of 1^st to 4^th grade and High School education or Haiyô presented an adjusted OR of 2.63 and 3.15, respectively, when compared to the unschooled individuals. Residing in the second group of villages resulted in a 42% lower chance of being excess weight as compared to residing in the first group of villages.

In the final multiple regression model, obesity only remained associated with statistical significance in the variables of age group and hunting/gathering. Being 20 to 49 years of age corresponded to a 11.1% higher chance of having obesity than that of individuals aged 15 to 20 years. Residing in a household that presents a medium frequency of hunting/gathering resulted in a 52% lower chance of having obesity when compared with those with a low level of consumption of foods produced by hunting/gathering (Table 4).

Discussion

The health of the Xavante has been the object of investigations conducted since the 1960’s with the purpose of characterizing their profile of health and morbidity-mortality. Since then, studies have investigated aspects that are connected directly or indirectly with health, such as genetic, demographic, anthropological, and epidemiological studies⁸8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002.^,1616 Carneiro O, Jardim PC. Blood pressure in a Xavante tribe. Comparison after 15 years. Arq Bras Cardiol 1993; 61(5):279-282.

17 Dal Fabbro AL, Franco LJ, Silva AS, Sartorelli DS, Soares LP, Franco LF, Kuhn PC, Moisés RS, Vieira-Filho JPB. High prevalence of type 2 diabetes mellitus in Xavante Indians from Mato Grosso, Brazil. Ethn Dis 2014; 24(1):35-40.^-1818 Welch JR, Ferreira AA, Tavares FG, Lucena JRM, Gomes de Oliveira MV, Santos RV, Coimbra Jr CEA. The Xavante Longitudinal Health Study in Brazil: objectives, design, and key results. Am J Hum Biol 2019; 32(2):e23339.^,2525 Arantes R, Santos RV, Coimbra Jr CEA. Saúde bucal na população indígena Xavánte de Pimentel Barbosa, Mato Grosso, Brasil. Cad Saude Publica 2001; 17(2):375-384.

26 Flowers N. Demographic crisis and recovery: a case study of the Xavante of Pimentel Barbosa. South Am Indian Stud 1994; 4:18-36.

27 Gugelmin SA, Santos RV. Human ecology and nutritional anthropometry of adult Xavánte Indians in Mato Grosso, Brazil. Cad Saude Publica 2001; 17(2):313-322.

28 Neel JV, Salzano FM, Junqueira PC, Keiter F, Maybury-Lewis D. Studies on the Xavante Indians of the Brazilian Mato Grosso. Am J Hum Genet 1964; 16(1):52-140.^-2929 Neel JV, Ward RH. The genetic structure of a tribal population, the Yanomama Indians. VI. Analysis by F-statistics (including a comparison with the Makiritare and Xavante). Genetics 1972; 72(4):639-666.. The Pimentel Barbosa and Etênhiritipá villages were the objective of many of those studies⁸8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002.^,1818 Welch JR, Ferreira AA, Tavares FG, Lucena JRM, Gomes de Oliveira MV, Santos RV, Coimbra Jr CEA. The Xavante Longitudinal Health Study in Brazil: objectives, design, and key results. Am J Hum Biol 2019; 32(2):e23339., but the other villages belonging to the Pimentel Barbosa IL have rarely been investigated. Our study was the first of its kind to report epidemiological data related to health from nearly all of the individuals residing in the IL of Pimentel Barbosa and Wedezé, the latter having only recently been established³⁰30 Welch JR, Santos RV, Flowers NM, Coimbra Jr CEA. Na primeira margem do rio: território e ecologia humana do povo Xavante de Wedezé. Rio de Janeiro: Museu do Índio; 2013..

The averages of height and weight obtained in this study are comparable to those verified in the previous survey conducted with the Xavante from the Pimentel Barbosa and Etênhiritipá villages in 2006. The same happened in relation to the values of Body Mass Index (BMI), given that the averages for men and women corresponded to 27.8 Kg/m² and 27.9 Kg/m², respectively in 2006¹⁰10 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.. In that study, Welch and collaborators conducted a temporal analysis of the nutritional state of the Xavante, revealing an average weight gain when comparing the findings of studies conducted in the 1960s by Neel²⁸28 Neel JV, Salzano FM, Junqueira PC, Keiter F, Maybury-Lewis D. Studies on the Xavante Indians of the Brazilian Mato Grosso. Am J Hum Genet 1964; 16(1):52-140. and Niswander³¹31 Niswander JD, Keiter F, Neel JV. Further studies on the Xavante Indians. II. Some anthropometric, dermatoglyphic, and nonquantitative morphological traits of the Xavantes of Simões Lopes. Am J Hum Genet 1967; 19(4):490-501., with later studies. The anthropometric surveys conducted with the Xavante from São Domingos and Simões Lopes, in the 1960’s, showed weight averages of 67.2 Kg for men and 54.0 Kg for women in São Domingos, and 69.8 Kg for men and 57.9 kg for women in Simões Lopes. The height averages were 168.1cm and 170.2cm for men and 154.7 cm and 156.3 cm for women, respectively, in the same villages.

An increase was noticeable in weight averages among the Xavante, when we compare the results of surveys conducted in 1977³²32 Flowers NM. Forager-farmers: the Xavante Indians of Central Brazil. New York: City University of New York; 1983. and in the 1990s²⁷27 Gugelmin SA, Santos RV. Human ecology and nutritional anthropometry of adult Xavánte Indians in Mato Grosso, Brazil. Cad Saude Publica 2001; 17(2):313-322.. In that study, the authors documented an increase in weight averages of 4.4 kg for men and 1.3 kg for women. Besides the high averages of BMI, our study also revealed a high prevalence of overweight and obesity, of 46.1% and 19.8%, respectively, which were 50.4% and 18.2% for women and 41.9% and 21.3% for men, respectively. This shows that only 34.1% of the Xavante population (36.8% of men and 31.4% of women), aged 15 years and older, residing in the studied IL, had a BMI within the standards of normality recommended by the WHO³³33 World Health Organization (WHO). A global brief on hypertension: silent killer, global public health crisis. Geneva: WHO; 2013.. In the general Brazilian population, in 2008-2009, the prevalence of excess weight reached 50.1% and 48.0% of adult men and women, respectively³⁴34 Conde WL, Monteiro CA. Nutrition transition and double burden of undernutrition and excess of weight in Brazil. Am J Clin Nutr 2014; 100(6):1617S-1622S..

When the results of this study are compared with the findings of the 1st National Health and Nutrition Survey of Indigenous Peoples (NHNSIP), conducted between 2008-2009, and based on a representative sample of Indigenous females residing in villages in the entire national territory, 14 to 49 years of age¹⁹19 Coimbra Jr CEA, Santos RV, Welch JR, Cardoso AM, Souza MC, Garnelo L, Rassi E, Follér ML, Horta BL. The First National Survey of Indigenous People's Health and Nutrition in Brazil: rationale, methodology, and overview of results. BMC Public Health 2013; 13:52., we noticed that the values found for Xavante women surpass the proportions observed in a national scale for excess weight and obesity, reaching 46.2% and 15.8%, respectively. The same conclusion applies to the comparison of the prevalence reported for Indigenous women from the Midwest region, where the population of the current study lives (52.8% and 17.2%)⁷7 Coimbra Jr CEA, Tavares FG, Ferreira AA, Welch JR, Horta BL, Cardoso AM, Santos RV. Socioeconomic determinants of excess weight and obesity among Indigenous women: findings from the First National Survey of Indigenous People's Health and Nutrition in Brazil. Public Health Nutr 2021; 24(7):1941-1951.. When we use the same age group from the national survey in the verification of prevalence, the levels of excess weight and obesity among Xavante women were even more pronounced, reaching 69.9% and 20.4%, respectively.

Sadly, this kind of result has been seen increasingly more often in the Brazilian Indigenous context. A high prevalence of overweight and obesity are recurring findings in studies conducted throughout the country. In many of those investigations, this kind of prevalence surpasses the 60% mark, as in the case of studies conducted with the Parkatêjê people, which verified excess weight prevalence of 62.5% among women³⁵35 Capelli JCS, Koifman S. Evaluation of the nutritional status of the Parkatêjê indigenous community in Bom Jesus do Tocantins, Pará, Brazil. Cad Saude Publica 2001; 17(2):433-437. and 67.8% and 14.4% of excess weight and obesity for both sexes, respectively³⁶36 Tavares EF, Vieira-Filho JPB, Andriolo A, Sañudo A, Gimeno SGA, Franco LJ. Metabolic profile and cardiovascular risk patterns of an Indian tribe living in the Amazon Region of Brazil. Hum Biol 2003; 75(1):31-46.. In the Amazon region, a study conducted by Lourenço and collaborators⁹9 Lourenco AEP, Santos RV, Orellana JDY, Coimbra CEAJ. Nutrition transition in Amazonia: obesity and socioeconomic change in the Surui Indians from Brazil. Am J Hum Biol 2008; 20(5):564-571. also revealed a significant prevalence, of 42.3% for overweight and 18.2% for obesity for both sexes. In addition to these studies, others, which focused on specific Indigenous populations from different regions, also found a high prevalence of overweight and obesity¹³13 Baldoni NR, Aquino JA, Alves GCS, Sartorelli DS, Franco LJ, Madeira SP, Dal Fabbro AL. Prevalence of overweight and obesity in the adult indigenous population in Brazil: a systematic review with meta-analysis. Diabetes Metab Syndr 2019; 13(3):1705-1715.^,1515 Fávaro TR, Santos RV, Cunha GM, Leite IC, Coimbra Jr CEA. Obesidade e excesso de peso em adultos indígenas Xukuru do Ororubá, Pernambuco, Brasil: magnitude, fatores socioeconômicos e demográficos associados. Cad Saude Publica 2015; 31(8):1685-1697.^,2727 Gugelmin SA, Santos RV. Human ecology and nutritional anthropometry of adult Xavánte Indians in Mato Grosso, Brazil. Cad Saude Publica 2001; 17(2):313-322.^,3737 Cardoso AM, Mattos IE, Koifman RJ. Prevalence of risk factors for cardiovascular disease in the Guaraní-Mbyá population of the State of Rio de Janeiro. Cad Saude Publica 2001; 17(2):345-354.

38 Leite MS, Santos RV, Coimbra CEA. Seasonality and nutritional status of indigenous peoples: the case of Wari' in Rondônia State, Brazil. Cad Saude Publica 2007; 23(11):2631-2642.^-3939 Oliveira GF, Oliveira TRR, Ikejiri AT, Galvao TF, Silva MT, Pereira MG. Prevalence of obesity and overweight in an Indigenous population in Central Brazil: a population-based cross-sectional study. Obes Facts 2015; 8(5):302-310..

When we compare the results of our study with those of other surveys conducted with the Xavante people, some differences are relevant. When we contrast the prevalence of excess weight and obesity in our study, with what was found by the study of the Xavante from Pimentel Barbosa/Etênhiritipá (66.7% and 20.8% for men and 55.6% and 17.3% for women, respectively), we can notice similarities, except for a smaller difference in the prevalence of excess weight among women, found by the work of Welch et al.¹⁰10 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26. Likewise the results found for obesity among the Xavante people from the villages of Sangradouro-Volta Grande and Pimentel Barbosa (24.6% of the men and 41.3% of the women) showed lower prevalences in the present study²⁷27 Gugelmin SA, Santos RV. Human ecology and nutritional anthropometry of adult Xavánte Indians in Mato Grosso, Brazil. Cad Saude Publica 2001; 17(2):313-322..

Given this scenario, we consider the continuous investigation on the health of specific Indigenous communities, with the analysis of their anthropometric profile in different moments, as something fundamental for the verification of secular tendencies of prevalence of nutritional deficiencies. Moreover, such an approach enables the observation of associations between nutritional state and the socioeconomic changes that those communities have endured, with the monetization of Indigenous economy and a decrease in the frequency of physical activities⁸8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002.^,99 Lourenco AEP, Santos RV, Orellana JDY, Coimbra CEAJ. Nutrition transition in Amazonia: obesity and socioeconomic change in the Surui Indians from Brazil. Am J Hum Biol 2008; 20(5):564-571.^,2727 Gugelmin SA, Santos RV. Human ecology and nutritional anthropometry of adult Xavánte Indians in Mato Grosso, Brazil. Cad Saude Publica 2001; 17(2):313-322.^,4040 Sampei MA, Canó EN, Fagundes U, Lima EES, Rodrigues D, Sigulem DM, Baruzzi RG. Anthropometric assessment of Kamayurá adolescents in the Upper Xingu, Central Brazil (2000-2001). Cad Saude Publica 2007; 23(6):1443-1453..

In the context of the Xavante, the expansion of the demographic and economic frontiers have, historically, impacted their territories, resulting in a loss of lands, environmental degradation, and an introduction of new economic relationships⁸8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002.^,2828 Neel JV, Salzano FM, Junqueira PC, Keiter F, Maybury-Lewis D. Studies on the Xavante Indians of the Brazilian Mato Grosso. Am J Hum Genet 1964; 16(1):52-140.. Traditional economy, based on subsistence farming, hunting, fishing, and gathering, has been substituted for outside economic relationships, compromising their autonomy and food source sustainability and leading to a dependence on industrialized foods⁸8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002..

Such foods, which are rich in carbohydrates and fats, have contributed for an increase in caloric intake, and the lack of physical activity resulting from factors like the decline in traditional practices that demanded physical effort and considering the mechanization of agriculture, leading to a sedentary way of life (with more time in front of the TV and doing other leisure activities), which resulted in less energy being spending¹⁰10 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.^,4141 Lucena JRM, Coimbra CEA, Silva CMFP, Welch JR. Prevalence of physical inactivity and associated socioeconomic indicators in indigenous Xavante communities in Central Brazil. BMC Nutrition 2016; 2(1):37.^,4242 Welch JR. Xavante ritual hunting: anthropogenic fire, reciprocity, and collective landscape management in the Brazilian Cerrado. Hum Ecol 2014; 42(1):47-59.. This shows how historical and socioeconomic determinants have influenced patterns of eating and of physical activity, thus contributing to an increasing prevalence of excess weight and obesity, as well as for other health illnesses, such as diabetes and hypertension¹⁷17 Dal Fabbro AL, Franco LJ, Silva AS, Sartorelli DS, Soares LP, Franco LF, Kuhn PC, Moisés RS, Vieira-Filho JPB. High prevalence of type 2 diabetes mellitus in Xavante Indians from Mato Grosso, Brazil. Ethn Dis 2014; 24(1):35-40..

When we examine the prevalence of excess weight and obesity in relation to the patterns of food consumption, we can notice that the highest prevalence occurred in the low levels of the frequency of the consumption of foods from hunting, fishing, and gathering, as well as from agriculture and livestock farming. For this last category, the difference observed proved only to be statistically significant for the excess weight outcome (p < 0.05). This pattern suggests that the Indigenous individuals residing in households with less practice of traditional means of subsistence had higher frequencies of excess weight and obesity, a result analogous to what is found for Indigenous populations throughout the country⁷7 Coimbra Jr CEA, Tavares FG, Ferreira AA, Welch JR, Horta BL, Cardoso AM, Santos RV. Socioeconomic determinants of excess weight and obesity among Indigenous women: findings from the First National Survey of Indigenous People's Health and Nutrition in Brazil. Public Health Nutr 2021; 24(7):1941-1951..

A relationship comparable to the National Survey can be seen as well in terms of the socioeconomic indicator “owned household goods”. In this context, a higher prevalence of obesity was observed in the medium and high strata. These results are in agreement with those of the NHNSIP, in which the index of owned household goods and the presence of regular family income showed positive associations with excess weight and obesity in multivariate analyses⁷7 Coimbra Jr CEA, Tavares FG, Ferreira AA, Welch JR, Horta BL, Cardoso AM, Santos RV. Socioeconomic determinants of excess weight and obesity among Indigenous women: findings from the First National Survey of Indigenous People's Health and Nutrition in Brazil. Public Health Nutr 2021; 24(7):1941-1951.. Furthermore, this association reflects similarities with what was found for the Saruí people, for whom the higher socioeconomic stratum had the highest obesity prevalence⁹9 Lourenco AEP, Santos RV, Orellana JDY, Coimbra CEAJ. Nutrition transition in Amazonia: obesity and socioeconomic change in the Surui Indians from Brazil. Am J Hum Biol 2008; 20(5):564-571..

When adjusted in multivariate analyses, the variables of sex, village group, age group, education, and pattern of the acquisition of food by agriculture and livestock farming demonstrated significant associations with the excess weight outcome. By contrast, in the model associated with obesity, only the variables of age group and pattern of the acquisition of food by hunting, fishing, or gathering remained in the final model. The associations found in our study converge with those found for other Indigenous populations in Brazil¹⁵15 Fávaro TR, Santos RV, Cunha GM, Leite IC, Coimbra Jr CEA. Obesidade e excesso de peso em adultos indígenas Xukuru do Ororubá, Pernambuco, Brasil: magnitude, fatores socioeconômicos e demográficos associados. Cad Saude Publica 2015; 31(8):1685-1697.^,3939 Oliveira GF, Oliveira TRR, Ikejiri AT, Galvao TF, Silva MT, Pereira MG. Prevalence of obesity and overweight in an Indigenous population in Central Brazil: a population-based cross-sectional study. Obes Facts 2015; 8(5):302-310.. For example, a study conducted with the Xukuru people from Ororubá found that the highest prevalence of excess weight and obesity was associated with the female sex and the older age groups¹⁵15 Fávaro TR, Santos RV, Cunha GM, Leite IC, Coimbra Jr CEA. Obesidade e excesso de peso em adultos indígenas Xukuru do Ororubá, Pernambuco, Brasil: magnitude, fatores socioeconômicos e demográficos associados. Cad Saude Publica 2015; 31(8):1685-1697..

The positive association between age and excess weight is a finding that is recurrent in scientific literature, and it is often more pronounced among women. The relationship between older age and predisposition to excess weight may be attributed to changes in basal metabolic rate and to modifications in lifestyle, including the reduction of traditionally practiced physical activities. We can infer that the association between being excess weight and being female may reflect cultural and gender dynamics which influence the patterns of eating and of physical activities. It is plausible to consider that sociocultural factors, such as traditional gender roles, are contributing to the observed pattern. Moreover, aspects related to household tasks and family care may affect the availability of time for regular physical activities.

The association found between the reduction of frequency of traditional practices of food acquisition, such as agriculture, livestock farming, and hunting, fishing, and gathering activities, and the presence of excess weight and obesity, indicates the possibility that these populations are acquiring eating patterns based on the regional market and the consumption of industrialized foods. Reduction of physical activity was also related with more dependence on industrialized foods among the Xavante⁸8 Coimbra Jr CEA, Flowers NM, Salzano FM, Santos RV. The Xavante in transition: health, ecology, and bioanthropology in Central Brazil. Ann Arbor: University of Michigan Press; 2002.^,1010 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.. Such findings indicate a potential change in the subsistence conditions and eating patterns in those villages¹⁰10 Welch JR, Ferreira AA, Santos RV, Gugelmin SA, Werneck G, Coimbra CEA. Nutrition transition, socioeconomic differentiation, and gender among adult Xavante Indians, Brazilian Amazon. Hum Ecol 2009; 37(1):13-26.^,1515 Fávaro TR, Santos RV, Cunha GM, Leite IC, Coimbra Jr CEA. Obesidade e excesso de peso em adultos indígenas Xukuru do Ororubá, Pernambuco, Brasil: magnitude, fatores socioeconômicos e demográficos associados. Cad Saude Publica 2015; 31(8):1685-1697.^,1818 Welch JR, Ferreira AA, Tavares FG, Lucena JRM, Gomes de Oliveira MV, Santos RV, Coimbra Jr CEA. The Xavante Longitudinal Health Study in Brazil: objectives, design, and key results. Am J Hum Biol 2019; 32(2):e23339..

Considering education level, a positive association tendency was verified with the occurrence of excess weight. However, this finding contradicts results found in studies considering the general population of Brazil, which indicate an inverse relationship between education and excess weight and obesity outcomes⁴³43 Monteiro CA, Conde WL, Popkin BM. Independent effects of income and education on the risk of obesity in the Brazilian adult population. J Nutr 2001; 131(3):881S-886S.. The results found for the Xavante also diverge from those of the National Survey of Indigenous Health, in which education was identified as a protection factor against overweight and obesity⁷7 Coimbra Jr CEA, Tavares FG, Ferreira AA, Welch JR, Horta BL, Cardoso AM, Santos RV. Socioeconomic determinants of excess weight and obesity among Indigenous women: findings from the First National Survey of Indigenous People's Health and Nutrition in Brazil. Public Health Nutr 2021; 24(7):1941-1951..

The growing prevalence of excess weight and obesity among the Xavante is a warning of the sociocultural, economic, and environmental changes taking place in the Xavante villages and their repercussions on health and food security of these populations. Protection of Indigenous land is essential for guaranteeing access to traditional, healthy foods. Food security is essential, requiring policies that can promote the autonomy of Indigenous people in terms of managing their natural resources and preserving sustainable eating habits. These findings highlight the need for the implementation of healthcare policies that consider the specific needs of Indigenous populations, respecting their traditions and worldviews.

Acknowledgements

The authors wish to thank the support and assistance provided by the Indigenous leaders and members of the communities studied, as well as the local Fundação Nacional dos Povos Indígenas (FUNAI) staff and the Fundação Nacional de Saúde (FUNASA). We thank the trust and support of Carlos E.A. Coimbra Jr and James R. Welch, researchers from the ENSP/FIOCRUZ, who coordinated the survey that generated the data used in the present article (projects CNPq 475674/2008-1 and 307624/2017-0 and Fiocruz/Inova-ENSP).

References

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