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Objective:The cutoffs defining anaemia based on haemoglobin and haematocrit recommended by the World Health Organization (WHO) and the United States (US) are different. We compared the prevalences resulting from these definitions and explored the reasons for the variation observed.Design:A cross-sectional survey within a cohort study of children recruited at birth at Royal Darwin Hospital.Setting:Subjects were interviewed in their homes or other convenient location and had a blood sample drawn.Subjects:Five hundred and seventeen Australian Aboriginal children aged 9–13 years inclusive.Results:Depending on the criterion used, the prevalence of anaemia in the total group ranged between 6% (95% confidence interval: 4.1–8.4%) and 24.4% (20.7–28.3). Using the WHO criteria, girls aged 12–13 years were identified as a target group, having a two- to-six fold higher prevalence than the other groups. When compared to the US criteria, boys aged 12–13 years had the highest prevalence of anaemia, although this was not significant. Simulations show that the WHO cutoffs are based on inconsistent centiles of the age–sex haemoglobin and haematocrit distributions, and that this largely explains the discrepant results.Conclusions:This variability in definition could lead to inappropriate identification of target groups for intervention programmes.Sponsorship:National Health and Medical Research Council of Australia, the Colonial Foundation and the Channel 7 Children's Research Foundation of South Australia Inc.European Journal of Clinical Nutrition (2007) 61, 135–139. doi:10.1038/sj.ejcn.1602483; published online 19 July 2006 [ABSTRACT FROM AUTHOR]

Background/Objectives:The aim of this paper was to compare methods to estimate usual intake distributions of nutrients and foods. As 'true' usual intake distributions are not known in practice, the comparison was carried out through a simulation study, as well as empirically, by application to data from the European Food Consumption Validation (EFCOVAL) Study in which two 24-h dietary recalls (24-HDRs) and food frequency data were collected. The methods being compared were the Iowa State University Method (ISU), National Cancer Institute Method (NCI), Multiple Source Method (MSM) and Statistical Program for Age-adjusted Dietary Assessment (SPADE).Subjects/Methods:Simulation data were constructed with varying numbers of subjects (n), different values for the Box-Cox transformation parameter (λBC) and different values for the ratio of the within- and between-person variance (rvar). All data were analyzed with the four different methods and the estimated usual mean intake and selected percentiles were obtained. Moreover, the 2-day within-person mean was estimated as an additional 'method'. These five methods were compared in terms of the mean bias, which was calculated as the mean of the differences between the estimated value and the known true value. The application of data from the EFCOVAL Project included calculations of nutrients (that is, protein, potassium, protein density) and foods (that is, vegetables, fruit and fish).Results:Overall, the mean bias of the ISU, NCI, MSM and SPADE Methods was small. However, for all methods, the mean bias and the variation of the bias increased with smaller sample size, higher variance ratios and with more pronounced departures from normality. Serious mean bias (especially in the 95th percentile) was seen using the NCI Method when rvar=9, λBC=0 and n=1000. The ISU Method and MSM showed a somewhat higher s.d. of the bias compared with NCI and SPADE Methods, indicating a larger method uncertainty. Furthermore, whereas the ISU, NCI and SPADE Methods produced unimodal density functions by definition, MSM produced distributions with 'peaks', when sample size was small, because of the fact that the population's usual intake distribution was based on estimated individual usual intakes. The application to the EFCOVAL data showed that all estimates of the percentiles and mean were within 5% of each other for the three nutrients analyzed. For vegetables, fruit and fish, the differences were larger than that for nutrients, but overall the sample mean was estimated reasonably.Conclusions:The four methods that were compared seem to provide good estimates of the usual intake distribution of nutrients. Nevertheless, care needs to be taken when a nutrient has a high within-person variation or has a highly skewed distribution, and when the sample size is small. As the methods offer different features, practical reasons may exist to prefer one method over the other. [ABSTRACT FROM AUTHOR]

Background/objectives: We studied the ecologic relationships of food groups, macronutrients, eating patterns, and an a priori food pattern score (Mediterranean Adequacy Index: MAI) with long-term CHD mortality rates in the Seven Countries Study.Subjects/methods: Sixteen cohorts (12,763 men aged 40-59 years) were enrolled in the 1960s in seven countries (US, Finland, The Netherlands, Italy, Greece, former Yugoslavia: Croatia/Serbia, Japan). Dietary surveys were carried out at baseline and only in a subsample of each cohort. The average food consumption of each cohort was chemically analyzed for individual fatty acids and carbohydrates.Results: Ecologic correlations of diet were computed across cohorts for 50-year CHD mortality rates; 97% of men had died in cohorts with 50-year follow-up. CHD death rates ranged 6.7-fold among cohorts. At baseline, hard fat was greatest in northern Europe, olive oil in Greece, meat in the US, sweet products in northern Europe and the US, and fish in Japan. The MAI was high in Mediterranean and Japanese cohorts. The 50-year CHD mortality rates of the cohorts were closely positively ecologically correlated (r = 0.68-0.92) with average consumption of hard fat, sweet products, animal foods, saturated fat, and sucrose, but not with naturally occurring sugars. Vegetable foods, starch, and the a priori pattern MAI were inversely correlated (r = -0.59 to -0.91) with CHD mortality rates.Conclusions: Long-term CHD mortality rates had statistically significant ecologic correlations with several aspects of diet consumed in the 1960s, the traditional Mediterranean and Japanese patterns being rich in vegetable foods, and low in sweet products and animal foods. [ABSTRACT FROM AUTHOR]

In 2013, the American Medical Association (AMA) decided to recognize obesity as a disease. One of the main arguments presented in favor of this was broadly 'utilitarian': the disease label would, it was claimed, provide more benefits than harms and thereby serve the general good. Several individuals and groups have argued that this reasoning is just as powerful in the European context. Drawing mainly on a review of relevant social science research, we discuss the validity of this argument. Our conclusion is that in a Western European welfare state, defining obesity as a disease will not on balance serve the general good, and that it is therefore more appropriate to continue to treat obesity as a risk factor. The main reasons presented in favor of this conclusion are: It is debatable whether a disease label would lead to better access to care and preventive measures and provide better legal protection in Europe. Medicalization and overtreatment are possible negative effects of a disease label. There is no evidence to support the claim that declaring obesity a disease would reduce discrimination or stigmatization. In fact, the contrary is more likely, since a disease label would categorically define the obese body as deviant. [ABSTRACT FROM AUTHOR]

Background/objectives: Recent long-term prospective cohort studies found inverse associations between chocolate consumption and the risk of type 2 diabetes, but provided conflicting evidence on the nature of the association among women. To assess this association in a large cohort of American women.Subjects/methods: Multivariable Cox regression was used with the data from 92 678 postmenopausal women in the prospective Women's Health Initiative study. Chocolate intake was assessed by food frequency questionnaire. Incidence of type 2 diabetes was determined by self-report of the first treatment with oral medication or insulin.Results: Among women free of diabetes at baseline, there were 10 804 cases, representing an incidence rate of 11.7% during 13.1 years and 1 164 498 person-years of follow-up. There was no significant linear association between long-term chocolate intake and type 2 diabetes risk, but there was significantly reduced risk at moderate levels of intake. Compared to women who ate 1 oz. of chocolate <1 time per month, those who ate this amount 1-<1.5 times per month, 1.5-<3.5 times per month, 3.5 times per month to <3 times per week and ⩾3 times per week had hazard ratios of 0.97 (95% confidence interval: 0.92, 1.04), 0.92 (0.87, 0.98), 0.93 (0.88, 0.98) and 0.98 (0.92, 1.04) (P for linear trend=0.79). There was only evidence of such inverse associations for women with below-median physical activity (P for interaction <0.0001) and those with age<65 years (P=0.01).Conclusions: We only found an inverse association between chocolate consumption and type 2 diabetes at moderate levels of consumption in two subgroups of postmenopausal women in the Women's Health initiative cohort. [ABSTRACT FROM AUTHOR]

Background/objectives: Evidence regarding the consumption of soy foods and isoflavones in relation to risk of type 2 diabetes (T2D) is scarce. Our study was to evaluate the association between soy food and isoflavone consumption and risk of T2D in US men and women.Subjects/methods: We followed 63 115 women in the Nurses' Health Study (1998-2012), 79 061 women in the Nurses' Health Study II (1999-2013) and 21 281 men in the Health Professionals Follow-Up Study (2002-2010). Diet was assessed by a validated food-frequency questionnaire and was updated every 4 years. Self-reports of incident T2D were confirmed by a validated supplementary questionnaire.Results: During 1 966 321 person-years of follow-up, 9185 incident T2D cases were documented. After multivariate adjustment for covariates, consumption of soy foods (tofu and soy milk) was not associated with a lower T2D risk. Compared with non-consumers of soy foods, the hazard ratio (HR) was 1.00 (95% confidence interval (CI): 0.93, 1.07) for <1 serving/week and 0.93 (95% CI: 0.83, 1.03) for ⩾1 serving/week of soy foods (P for trend=0.14). In contrast, intake of total isoflavones was inversely associated with T2D risk. Comparing extreme quintiles of isoflavones, the HR was 0.89 (95% CI: 0.83, 0.96; P for trend=0.009). Inverse associations were also found for consumption of major individual isoflavones, including daidzein and genistein, with risk of T2D.Conclusions: Intake of isoflavones was associated with a modestly lower T2D risk in US men and women who typically consumed low-to-moderate amounts of soy foods. These findings warrant replications in other populations with similar soy intake levels. [ABSTRACT FROM AUTHOR]

Background/objectives: The objectives of this study were to determine the prevalence of muscle weakness using the two 2014 Foundation for the National Institutes of Health (FNIH) Sarcopenia Project criteria and its relationship with physical limitations, basic activities of daily living (ADL) and instrumental ADL.Subjects/methods: We performed a cross-sectional analysis of community-dwelling adults from the Health and Retirement Study 2006-2008 and identified a subsample of 5092 adults aged ⩾60 years with grip strength (GS) data. Self-reported physical limitations, basic ADL and instrumental ADL were assessed. Criteria for GS (men<26 kg; women <16 kg) and GS adjusted for body mass index (GS/BMI; men <1.0; women <0.56) were applied to the sample. We determined the prevalence of muscle weakness in each sex. Multivariable logistic regression was used to calculate the association of physical limitations, basic ADL and instrument ADL with weakness definitions in each sex.Results: Mean age was 72.1 years (54.9% female). Mean GS was 38.3 and 22.9 kg and mean BMI was 29 kg/m2, respectively, in men and women. Weakness prevalence using GS and GS:BMI definitions were 7.8 and 15.2 (P<0.001), respectively, in men and 11.4 and 13.3% (P=0.04) in women. Overall prevalence of physical limitations, basic ADL limitations and instrumental ADL limitations was 52.9, 28.1 and 35.9%, respectively. In those with weakness, prevalence of physical limitations, basic ADL and instrumental ADL was 78.5, 42.3 and 65.3%, respectively, using the GS definition, and 79.7, 40.7 and 58.8%, respectively, using the GS/BMI definition. GS and the GS/BMI definitions of weakness were strongly associated with physical limitations (odds ratio (OR) 2.19 (95% confidence interval (CI): (1.67-2.87)) and 2.52 (2.01-3.17)), basic ADL (OR 1.59 (1.22-2.07) and 1.66 (1.32-2.07)) and instrumental ADLs (OR 1.98 (1.28-2.54) and 1.78 (1.44-2.20)).Conclusions: The new FNIH guidelines for weakness are associated with higher prevalence of physical limitations, basic ADL impairments and instrumental ADL impairments as compared with individuals without weakness. [ABSTRACT FROM AUTHOR]

Background:Historically, the voluntary addition of micronutrients to foods in the United States has been regarded as an important means to lessen problems of nutrient inadequacy. With expanding voluntary food fortification and widespread supplement use, it is important to understand how voluntary food fortification has an impact on the likelihood of excessive usual intakes. Our objective was to investigate whether individuals in the United States with greater frequency of exposure to micronutrients from voluntarily fortified foods (vFF) are more likely to have usual intakes approaching or exceeding the respective tolerable upper intake levels (UL).Subjects/methods:The National Cancer Institute method was applied to data from the 2007-2008 National Health and Nutrition Examination Survey (NHANES) to estimate the joint distribution of usual intake from both vFF and non-vFF sources for 12 nutrients and determine the probability of consuming these nutrients from vFF on a given day. For each nutrient, we estimated the distribution of usual intake from all food sources by quintile of probability of consuming vFF and compared the distributions with ULs.Results:An increased probability of consuming zinc, retinol, folic acid, selenium and copper from vFF was associated with a greater risk of intakes above the UL among children. Among adults, increased probability of consuming calcium and iron from vFF was associated with a greater risk of intakes above the UL among some age/sex groups.Conclusion:The high nutrient exposures associated with vFF consumption in some population subgroups suggest a need for more careful weighing of the risks and benefits of uncontrolled food fortification. [ABSTRACT FROM AUTHOR]

Objective:To compare childhood obesity prevalence in England and the United States using different criteria.Subjects/Methods:Participants included 2- to 17-year olds in the Health Survey for England (HSE, n=33 563) and the US National Health and Nutrition Examination Survey (NHANES, n=14 540) 1999 through 2006. Mean body mass index (BMI) and prevalence of obesity were compared using the UK 1990, US 2000 Centers for Disease Control and International Obesity Task Force (IOTF) criteria.Results:English children at ages 2-5 years had a higher mean BMI than US children (mean difference (English minus US)=0.41 kg/m2, 95% confidence intervals (CI) 0.31-0.52). At age 8 years, mean BMI was lower in England (for ages 8-11 years, mean difference=−1.00 kg/m2, 95% CI −1.26 to −0.75; for ages 12-17 years, mean difference=−1.37 kg/m2, 95% CI −1.59 to −1.14). The IOTF criteria produced the lowest estimates of obesity prevalence. The 2000 Centre for Disease Control and Prevention (CDC) criteria produced the highest estimates in younger children and the UK 1990 criteria produced the highest in adolescents. Children aged 2-5 years in England had higher prevalence of obesity than those in the United States when using the 2000 CDC and UK 1990 criteria. US adolescents had the highest prevalence of obesity by age group using each of the three criteria.Conclusion:The 2000 CDC and UK 1990 criteria give a higher prevalence of obesity in England than in the United States at ages 2-5 years; however, at age 8 years, the reverse is true. Estimates of childhood obesity prevalence rely on the criteria used, which has implications for surveillance and clinical practice. [ABSTRACT FROM AUTHOR]

This study compared nutrient intakes from 7-day menus for the US MyPlate and DASH Eating Plan versus the cutoff points for green lights defined by the UK's multiple traffic light (MTL) scheme. For both diets, the foods achieved green lights for saturated fat and salt, and for beverages for total fat, saturated fat and salt. The other nutrients achieved amber lights but were within the range of the two diets. By contrast, the MTL threshold for salt in beverages was outside the range of the diets. The values for salt in beverages in the MyPlate and Dash diet plans were 0.06±0.07 and 0.19±0.01 (s.d.) g/100 ml, which are both considerably lower compared with the cutoff of 0.3 g/100 ml for an MTL green light. Adjusting the green MTL threshold values to the median values for a healthful diet could help make MTL labelling a more valid way of helping consumers choose a healthful diet. [ABSTRACT FROM AUTHOR]

Background:No nationally representative data from middle- and low-income countries have been analyzed to compare the prevalence of underweight and overweight, defined by using the Centers for Disease Control and Prevention (CDC) and the International Obesity TaskForce (IOTF) body mass index cut points.Objective:To examine the consistency in the prevalence of underweight and overweight, defined by using the CDC and IOTF cut points in Chinese, Indonesian and Vietnamese children.Methods:We used data from 1600 Chinese, 11 756 Indonesian and 53 826 Vietnamese children aged 2–18 years, who participated in three recent, representative surveys in China, Indonesia and Vietnam. A smaller difference between prevalence and a higher κ-statistic indicated a higher consistency level.Results:The prevalence of underweight was higher with the IOTF than the CDC cut points; absolute differences in the Chinese, Indonesian and Vietnamese were 6, 10 and 13% (boys), and 10, 13 and 19% (girls), respectively. The prevalence of overweight was more consistent (absolute differences were <2%, except for the 2–5.9-year-old Chinese and Indonesian children (from 2 to <5%)). Values of κ-statistic (from 0.55 to 0.88) varied by age, sex and ethnicity. The consistency was gradually improving from the Vietnamese to Indonesians and to Chinese boys and girls, from girls to boys, from the younger to older boys and from the older to younger girls.Conclusions:The age, sex and ethnic differences in the prevalence of underweight and overweight suggest a systematic evaluation of the cut points. [ABSTRACT FROM AUTHOR]

Background/Objectives:Nutrient profiling of foods is defined as the science of ranking or classifying foods based on their nutrient content. Nutrient profiles can be calculated based on 100 g or 100 kcal of food or on standard serving sizes. The objective of this study was to compare the performance of nutrient profiles based on 100 g, 100 kcal and government-mandated serving sizes, and to identify the optimal base of calculation.Subjects/Methods:Nutrient profiles tested were composed of positive subscores based on nutrients to encourage and negative subscores based on nutrients to limit. Alternative profiles, computed using different bases of calculation, were used to rank order 378 commonly consumed foods from a food frequency instrument. Profile performance was tested with respect to the foods’ energy density.Results:Serving sizes, defined by the US Food and Drug Administration as reference amounts customarily consumed (RACC), were inversely linked to energy density of foods. Positive subscores based on 100 kcal were equivalent to those calculated using RACC values. Negative subscores performed better when based on 100 g as opposed to 100 kcal.Conclusions:Models based on serving sizes and on 100 kcal were preferable for positive subscores and models based on 100 g of food were preferable for negative subscores. RACC-based profiles may represent an attractive option for the US consumer.European Journal of Clinical Nutrition (2009) 63, 898–904; doi:10.1038/ejcn.2008.53; published online 5 November 2008 [ABSTRACT FROM AUTHOR]

Estimation of energy requirements relies on adequate values of basal metabolic rate (BMR). Prediction equations recommended for international use have been shown to overestimate BMR in populations living in the tropics. We have previously shown the inadequacy of these equations in samples of Brazilians living in tropical and temperate regions of the country. We sought to investigate whether BMR could adequately be estimated by prediction equations in a sample of Brazilians living in a different setting: the Sonoran desert of the Southwestern USA. BMR was measured under standard conditions in 33 subjects (14 men). Mean bias (estimated–measured) varied from 404.4 to 708.6 kJ day−1 in women and 566.8 to 1122.8 kJ day−1 in men, representing 8.5–15 and 8.9–17.6% overestimation, respectively, using the Schofield equations. Bland and Altman analyses showed large, relevant limits of agreement. The results using the recommended equations for the American population (IOM, 2005) were only 2% different from the Schofield equations. The Harris and Benedict equations yielded higher overestimations (15.0 and 16.8% for women and men, respectively) and the Henry and Rees equations also overestimated BMR (8.5 and 8.9%) even though they were developed for populations from the tropics, although to a lesser degree. It is concluded that the equations currently recommended for international use are not appropriate for Brazilians living in the Southwestern USA.European Journal of Clinical Nutrition (2007) 61, 290–294. doi:10.1038/sj.ejcn.1602498; published online 9 August 2006 [ABSTRACT FROM AUTHOR]

BACKGROUND:: There is a continuing need to examine the relationship between diet quality and health in the population. The Healthy Eating Index (HEI) has been developed as a composite measure of diet quality by the US Department of Agriculture. OBJECTIVES:: The first objective was to use the HEI to assess the diet quality of a representative sample of the US population and population groups. The second objective was to examine the association between HEI and obesity. DESIGN:: Cross-sectional analysis of data from 10?930 adults who participated in the Third National Health and Nutrition Examination Survey. Sociodemographic, physical activity, dietary, and health data were used in the analysis. Diet quality was assessed with the HEI score, ranging from 0 to 100, based on 10 dietary criteria. A low HEI score indicates poor diet. RESULTS:: A majority of survey participants had a low HEI score. The percentage of individuals classified as having a poor diet varied by age, gender, race/ethnicity, income, and education. A low HEI score was associated with overweight and obesity. There was a graded increase in the odds ratio of obesity across the HEI category after adjusting for age, gender, race/ethnicity, physical activity, smoking, alcohol use, income, and education. CONCLUSIONS:: An index of diet quality, such as HEI, may provide a comprehensive assessment of diet in the population. Since the HEI is based on the US Dietary Guidelines, the use of these guidelines as a way to improve health should be emphasized. However, the overall effectiveness of these guidelines in disease prevention needs to be studied further. SPONSORSHIP:: None.European Journal of Clinical Nutrition (2004) 58, 1580-1586. doi:10.1038/sj.ejcn.1601989 Published online 19 May 2004 [ABSTRACT FROM AUTHOR]

OBJECTIVE:: Maternal weight gain has been consistently linked to birth weight but, beyond maternal energy intake, no macronutrient has been associated with either of them. We have examined whether maternal energy-adjusted intake of macronutrients is associated with either maternal weight gain or birth-size parameters. DESIGN:: Cohort study. SETTING:: University hospital in Boston, USA. SUBJECTS:: A total of 224 pregnant women coming for their first routine prenatal visit. The women were followed through delivery. INTERVENTIONS:: None. Pregnant women's dietary intake during the second trimester was ascertained at the 27th week of pregnancy through a food frequency questionnaire. RESULTS:: Intake of neither energy nor any of the energy-generating nutrients was significantly associated with birth size. In contrast, maternal weight gain by the end of the second trimester of pregnancy was significantly associated with energy intake (+0.9?kg/s.d. of intake; P~0.006) as well as energy-adjusted intake of protein (+3.1?kg/s.d. of intake; P<10-4), lipids of animal origin (+2.6?kg/s.d. of intake; P<10-4) and carbohydrates (-5.2?kg/s.d. of intake; P<10-4). CONCLUSIONS:: Although maternal weight gain is strongly associated with birth size, the indicated nutritional associations with weight gain are not reflected in similar associations with birth-size parameters. The pattern is reminiscent of the sequence linking diet to coronary heart disease (CHD) through cholesterol: diet has been conclusively linked to blood cholesterol levels and cholesterol levels are conclusively linked to this disease, even though the association of diet with CHD has been inconclusive and controversial. SPONSORSHIP:: This study was supported in part by Grant No. CA54220 from the National Institutes of HealthEuropean Journal of Clinical Nutrition (2004) 58, 231-237. doi:10.1038/sj.ejcn.1601771 [ABSTRACT FROM AUTHOR]

Objective: To examine the relationships between circulating concentrations of C-reactive protein and concentrations of retinol, retinyl esters, vitamin C, vitamin E, carotenoids, and selenium. Design: Cross-sectional study using National Health and Nutrition Examination Survey III (1988-1994) data. Setting: United States population. Subjects: Up to 14519 US noninstitutionalized civilian men and women aged ≥20 y. Results: C-reactive protein concentration (dichotomized at the sex-specific 85th percentile) was inversely and significantly associated with concentrations of retinol, retinyl esters, vitamin C, α-carotene, β-carotene, cryptoxanthin, lutein/zeaxanthin, lycopene, and selenium after adjustment for age, sex, race or ethnicity, education, cotinine concentration, body mass index, leisure-time physical activity, and aspirin use. Conclusions: These results suggest that the inflammatory process, through the production of reactive oxygen species, may deplete stores of antioxidants. Whether increased consumption of foods rich in antioxidants or supplementation with antioxidants can provide health benefits to people characterized by elevated C-reactive protein concentrations may be worthy of further study. [ABSTRACT FROM AUTHOR]

Discusses the approach of the United States (US) Food and Nutrition Board to daily nutrient requirements and its relevance to Europe. Overview of the concept and approach of the US Food and Nutrition Board; Information on a model for development of tolerable upper intake levels; Case illustrations for upper tolerable levels of vitamin B6, folic acid and niacin intake; Recommendation for energy and nutrients intake in Europe; Conclusions.

Presents information on a study on the association between sugar consumption and dental caries, obesity and micronutrient dilution in different European countries. Data on European sugar intakes; Recommendations for sugar intakes in European countries; Conclusions.

Looks at the vitamin statuses of the socioeconomically disadvantaged preschool children in American children. Information on children studied; Methodology used; Discussion on the results.

The Maya people are descended from the indigenous inhabitants of southern Mexico, Guatemala and adjacent regions of Central America. In Guatemala, 50% of infants and children are stunted (very low height-for-age), and some rural Maya regions have >70% children stunted. A large, longitudinal, intergenerational database was created to (1) provide deep data to prevent and treat somatic growth faltering and impaired neurocognitive development, (2) detect key dependencies and predictive relations between highly complex, time-varying, and interacting biological and cultural variables and (3) identify targeted multifactorial intervention strategies for field testing and validation. Contributions to this database included data from the Universidad del Valle de Guatemala Longitudinal Study of Child and Adolescent Development, child growth and intergenerational studies among the Maya in Mexico and studies about Maya migrants in the United States. [ABSTRACT FROM AUTHOR]