Observational hints of radial migration in disc galaxies from CALIFA

Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important, galaxies with different surface brightness (SB) profiles must display differences in their stellar population properties. Aims: We investigate the role of radial migration in the light distribution and radial stellar content by comparing the inner colour, age, and metallicity gradients for galaxies with different SB profiles. We define these inner parts, avoiding the bulge and bar regions and up to around three disc scale lengths (type I, pure exponential) or the break radius (type II, downbending; type III, upbending). Methods: We analysed 214 spiral galaxies from the CALIFA survey covering different SB profiles. We made use of GASP2D and SDSS data to characterise the light distribution and obtain colour profiles of these spiral galaxies. The stellar age and metallicity profiles were computed using a methodology based on full-spectrum fitting techniques (pPXF, GANDALF, and STECKMAP) to the Integral Field Spectroscopic CALIFA data. Results: The distributions of the colour, stellar age, and stellar metallicity gradients in the inner parts for galaxies displaying different SB profiles are unalike as suggested by Kolmogorov-Smirnov and Anderson-Darling tests. We find a trend in which type II galaxies show the steepest profiles of all, type III show the shallowest, and type I display an intermediate behaviour. Conclusions: These results are consistent with a scenario in which radial migration is more efficient for type III galaxies than for type I systems, where type II galaxies present the lowest radial migration efficiency. In such a scenario, radial migration mixes the stellar content, thereby flattening the radial stellar properties and shaping different SB profiles. However, in light of these results we cannot further quantify the importance of radial migration in shaping spiral galaxies, and other processes, such as recent star formation or satellite accretion, might play a role

Bar pattern speeds in CALIFA galaxies: I. Fast bars across the Hubble sequence

The bar pattern speed ($\Omega_{\rm b}$) is defined as the rotational frequency of the bar, and it determines the bar dynamics. Several methods have been proposed for measuring $\Omega_{\rm b}$. The non-parametric method proposed by Tremaine \& Weinberg (1984; TW) and based on stellar kinematics is the most accurate. This method has been applied so far to 17 galaxies, most of them SB0 and SBa types. We have applied the TW method to a new sample of 15 strong and bright barred galaxies, spanning a wide range of morphological types from SB0 to SBbc. Combining our analysis with previous studies, we investigate 32 barred galaxies with their pattern speed measured by the TW method. The resulting total sample of barred galaxies allows us to study the dependence of $\Omega_{\rm b}$ on galaxy properties, such as the Hubble type. We measured $\Omega_{\rm b}$ using the TW method on the stellar velocity maps provided by the integral-field spectroscopy data from the CALIFA survey. Integral-field data solve the problems that long-slit data present when applying the TW method, resulting in the determination of more accurate $\Omega_{\rm b}$. In addition, we have also derived the ratio $\cal{R}$ of the corotation radius to the bar length of the galaxies. According to this parameter, bars can be classified as fast ($\cal{R}$ $1.4). For all the galaxies,$\cal{R}$is compatible within the errors with fast bars. We cannot rule out (at 95$\%$level) the fast bar solution for any galaxy. We have not observed any significant trend between$\cal{R}$ and the galaxy morphological type. Our results indicate that independent of the Hubble type, bars have been formed and then evolve as fast rotators. This observational result will constrain the scenarios of formation and evolution of bars proposed by numerical simulations.Comment: 17 pages, 10 figures, accepted for publication in A&

The influence of binarity on dust obscuration events in the planetary nebula M 2-29 and its analogues

The central star of the planetary nebula (CSPN) M 2-29 shows an extraordinary R Coronae Borealis-like fading event in its optical lightcurve. The only other CSPN to show these events are CPD-568032 (Hen 3-1333) and V651 Mon (NGC 2346). Dust cloud formation in the line of sight appears responsible but the exact triggering mechanism is not well understood. Understanding how planetary nebulae (PNe) trigger dust obscuration events may help understand the same process in a wide range of objects including Population-I WC9 stars, symbiotic stars and perhaps Asymptotic Giant Branch (AGB) stars with long secondary periods (LSPs). A binary scenario involving an eccentric, wide companion that triggers dust formation via interaction at periastron is a potential explanation that has been suggested for LSP variables. Model fits to the lightcurves of CPD-568032 and M 2-29 show the dust forms in excess of 70 AU at the inner edge of a dust disk. In the case of CPD-568032 this radius is far too large to coincide with a binary companion trigger, although a binary may have been responsible for the formation of the dust disk. We find no direct evidence to support previous claims of binarity in M 2-29 either from the OGLE lightcurve or deep medium-resolution VLT FLAMES spectroscopy of the CSPN. We classify the CSPN as Of(H) with T_eff=50+-10 kK and log g=4.0+-0.3. We find a mean distance of 7.4+-1.8 kpc to M 2-29 at which the M_V=-0.9 mag CSPN could potentially hide a subgiant luminosity or fainter companion. A companion would help explain the multiple similarities with D'-type symbiotic stars whose outer nebulae are thought to be bona-fide PNe. The 7.4 kpc distance, oxygen abundance of 8.3 dex and Galactic coordinates (l=4.0, b=-3.0) prove that M 2-29 is a Galactic Bulge PN and not a Halo PN as commonly misconceived.Comment: 15 pages, 14 figures, 7 tables. Accepted for publication in A\&

Nutritional valuation of schoolchildren from three Ibero-American countries: A comparative analysis of the references proposed by International Obesity Task Force (IOTF) and World Health Organization (WHO)

Introducción: El índice de masa corporal (IMC) resulta un indicador útil para valorar la condición nutricional en la infancia y adolescencia. Si bien no existe consenso respecto a los valores o puntos de corte de IMC que deben utilizarse para la diagnosis del sobrepeso, la obesidad o la insuficiencia ponderal, las referencias propuestas por la Organización Mundial de la Salud (OMS) y la International Obesity Task Force (IOTF) son las más aceptadas. No obstante, existen discrepancias importantes en los resultados obtenidos en función de una u otra referencia. Objetivo: Analizar y comparar la condición nutricional de una muestra internacional a partir del IMC, mediante la aplicación simultánea de las referencias recomendadas por la IOTF y la OMS. Métodos: Se calculó el IMC de 1289 escolares de 10 a 13 años de México, Venezuela y España. A cada niño le fue atribuida una categoría nutricional (bajo peso, normopeso, sobrepeso y obesidad) utilizando el criterio de la IOTF (puntos de corte equivalentes a 18,5; 25 y 30 en adultos) y OMS (-1 DE: bajo peso + 1 DE: sobrepeso y +2 DE: obesidad). Las prevalencias de estado nutricional obtenidas por cada criterio fueron comparadas mediante la prueba de Chi-Cuadrado. Resultados: El porcentaje de escolares en cada una de las categorías nutricionales varió significativamente en función de la referencia empleada. La prevalencia de malnutrición por exceso o por defecto fue, en ambos sexos y en los tres países, superior al emplear los parámetros OMS. La referencia OMS evidenció un 10,9% menos de niños normonutridos y un 13,1% más de malnutridos que la IOTF. Discusión: Los resultados de esta investigación permiten inferir que la referencia propuesta por la OMS resulta ser más “preventiva” al momento de identificar individuos malnutridos. Se subraya la importancia de especificar los criterios empleados para la determinación del estado nutricional en los estudios de carácter epidemiológico, así como de contrastar las referencias empleadas para el diagnóstico. Conclusiones: Las referencias OMS para IMC sobrestiman la prevalencia de bajo peso, sobrepeso y obesidad en relación a los puntos de corte propuestos por el IOTF para el diagnóstico de la malnutrición.Introduction: Body Mass Index (BMI) is a useful tool for assessing nutritional status in childhood and adolescence. Although there is no consensus on BMI values or cutoffs to be used for the diagnosis of overweight, obesity and underweight references proposed by World Health Organization (WHO) and International Obesity Task Force (IOTF) are the most accepted. However, there are significant discrepancies in the results obtained in terms of either reference. Objective: To analyze and compare the nutritional status of an international sample from IMC, by simultaneous application of IOTF and WHO recommended references. Methods: 1289 schoolchildren’s BMI between 10 and 13 years of Mexico, Venezuela and Spain was estimated. Each child was assigned a nutritional category (underweight, normal weight, overweight and obese) using the IOTF criteria (points cut equivalent to 18,5, 25 and 30 in adults) and WHO (-1 SD: low weight +1 DE: overweight and +2 SD: obesity). The prevalence of nutritional status of each criterion was compared using the Chi-square test. Results: The percentage of students in each of the nutritional categories mottled significantly depending on the reference used. The prevalence of excess or defect malnutrition, in both sexes and in all three countries, was exceeded using the WHO parameters. WHO reference showed 10,9% less than well-nourished children and 13,1 % more malnourished than the IOTF. Discussion: The results of this research allow inferring that the reference proposed by WHO appears to be more “protecting” when identifying malnourished individuals. The importance of specifying the criteria for determination of nutritional status in epidemiologic studies, as well as to contrast the references used for diagnosis, is emphasized. Conclusions: The WHO BMI references overestimate the prevalence of underweight, overweight and obesity in relation to the cutoff points proposed by the IOTF for diagnosing malnutrition.Fil: Bergel Sanchís, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Cesani Rossi, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Cordero, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucuman. Instituto Superior de Estudios Sociales; ArgentinaFil: Navazo, Bárbara. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Departamento Científico de Antropología. Cátedra de Antropología Biológica Iv; ArgentinaFil: Olmedo, S.. Programa de Ecología Reproductiva del Gran Chaco Argentino. Formosa; ArgentinaFil: Quintero, F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Departamento Científico de Antropología. Cátedra de Antropología Biológica Iv; ArgentinaFil: Sardi, Marina Laura. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Departamento de Antropología; ArgentinaFil: Torres, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Arechiga, J.. Universidad Nacional Autónoma de México; MéxicoFil: Méndez de Pérez, B. Universidad Nacional de Venezuela; VenezuelaFil: Marrodán, M. D.. Universidad Complutense de Madrid; Españ

Waist circumference percentiles for Hispanic-American children and comparison with other international references

Introduction Waist circumference (WC) constitutes an indirect measurement of central obesity in children and adolescents. Objective To provide percentiles of WC for Hispanic-American children and adolescents, and compare them with other international references. Materials and methods The sample comprised 13 289 healthy children between 6 and 18 years coming from public schools of middle and low socioeconomic levels in different parts of Argentina, Cuba, Spain, Mexico, and Venezuela. The LMS method to calculate WC percentiles was applied. Sex and age differences were assessed using Student'sttest and ANOVA (SPSS v.21.0). Comparisons were established with references from the United States, Colombia, India, China, Australia, Kuwait, Germany, Tunisia, Greece, and Portugal. Results WC increases with age in both sexes. Boys show higher WC in P3, P50, and P97. Comparison of 50th and 90th percentiles among populations from diverse sociocultural and geographical contexts shows high variability, not all justified by the measurement method. Discussion and conclusions Specific WC percentiles for sex and age, and P90 cut-off points are provided; these values are potentially useful to assess central obesity in Hispanic-American adolescent children

Analyzing multitarget activity landscapes using protein-ligand interaction fingerprints: interaction cliffs.

This is the original submitted version, before peer review. The final peer-reviewed version is available from ACS at http://pubs.acs.org/doi/abs/10.1021/ci500721x.Activity landscape modeling is mostly a descriptive technique that allows rationalizing continuous and discontinuous SARs. Nevertheless, the interpretation of some landscape features, especially of activity cliffs, is not straightforward. As the nature of activity cliffs depends on the ligand and the target, information regarding both should be included in the analysis. A specific way to include this information is using protein-ligand interaction fingerprints (IFPs). In this paper we report the activity landscape modeling of 507 ligand-kinase complexes (from the KLIFS database) including IFP, which facilitates the analysis and interpretation of activity cliffs. Here we introduce the structure-activity-interaction similarity (SAIS) maps that incorporate information on ligand-target contact similarity. We also introduce the concept of interaction cliffs defined as ligand-target complexes with high structural and interaction similarity but have a large potency difference of the ligands. Moreover, the information retrieved regarding the specific interaction allowed the identification of activity cliff hot spots, which help to rationalize activity cliffs from the target point of view. In general, the information provided by IFPs provides a structure-based understanding of some activity landscape features. This paper shows examples of analyses that can be carried out when IFPs are added to the activity landscape model.M-L is very grateful to CONACyT (No. 217442/312933) and the Cambridge Overseas Trust for funding. AB thanks Unilever for funding and the European Research Council for a Starting Grant (ERC-2013- StG-336159 MIXTURE). J.L.M-F. is grateful to the School of Chemistry, Department of Pharmacy of the National Autonomous University of Mexico (UNAM) for support. This work was supported by a scholarship from the Secretariat of Public Education and the Mexican government

Food and nutrition security discursive frames in the context of the Spanish economic crisis

[EN] The recent economic crisis in Spain has provoked a number of food and nutrition security (FNS) impacts that have fuelled a fragmented landscape of food-related debates, although these have not taken the form of a coherent and allembracing public discussion on national food security. This paper is an inductive analysis of such debates, mostly based on media coverage, in an attempt to disentangle the different discourse frames on FNS in Spain, and the role played by the economic crisis in the shaping and underpinning of such frames. For this purpose a frame matrix was constructed, paying particular attention to the stakeholders governance claims in order to confront frame-specific problems. Results show how stakeholders have used elements of the crisis to underpin or reinterpret their core arguments. In addition, governance claims have concentrated on the malfunctioning of the food chain, mostly due to unequal bargaining power, and the way this could be putting at risk crucial components of the food system and future FNS. Also, the short-termism of most stakeholders approaches obscures the long run threats to the Spanish food system.This research is part of the project "Assessment of the impact of global drivers of change on Europe's food security" (TRANSMANGO), granted by the EU under 7th Framework Programme, theme KBBE.2013.2.5-01, Grant agreement no: 613532. Authors gratefully appreciate the comments and suggestions made by the three anonymous reviewers and the editors of the Journal.OOrtiz Miranda, D.; Moreno Pérez, OM.; Arnalte Alegre, EV. (2016). Food and nutrition security discursive frames in the context of the Spanish economic crisis. Food Security. 8(3):665-677. https://doi.org/10.1007/s12571-016-0574-xS66567783Antentas, J. M., & Vivas, E. (2014). Impacto de la crisis en el derecho a una alimentación sana y saludable. Informe SESPAS 2014. Gaceta Sanitaria, 28(S1), 58–61.Brunori, G., Malandrin, V., & Rossi, A. (2013). Trade-off or convergence? The role of food security in the evolution of food discourse in Italy. Journal of Rural Studies, 29, 19–29.Candel, J. J., Breeman, G. E., Stiller, S. J., & Termeer, C. J. (2014). Disentangling the consensus frame of food security: the case of the EU common agricultural policy reform debate. Food Policy, 44, 47–58.CFS – Committee on World Food Security (2012). Coming to Terms with Terminology. http://www.fao.org/fsnforum/sites/default/files/file/Terminology/MD776(CFS___Coming_to_terms_with_Terminology).pdf . Accessed 6 Oct 2015.Cussó, X., & Garrabou, R. (2009). Dieta mediterránea y transición nutricional moderna en España. In L. G. Zubero, R. H. García, & J. M. Lázaro (Eds.), Economía Alimentaria en España durante el siglo XX (pp. 25–63). Madrid: MARM.De Schutter, O. (2014). The specter of productivism and food democracy. Wisconsin Law Review, 199, 199–233.DEFRA (2008). Ensuring the UK’s food security in a changing world. London: A Defra Discussion Paper.Díaz-Méndez, C., & Gómez-Benito, C. (2010). Nutrition and the Mediterranean diet. A historical and sociological analysis of the concept of a “healthy diet” in Spanish society. Food Policy, 35(5), 437–447.Dibden, J., Gibbs, D., & Cocklin, C. (2013). Framing GM crops as food security solution. Journal of Rural Studies, 29, 59–70.Ericksen, P. J. (2008). Conceptualizing food systems for global environmental change research. Global Environmental Change, 18, 234–245.FAO (2014). The State of the World’s Land and Water Resources for Food and Agriculture. http://www.fao.org/nr/solaw/maps-and-graphs/en/ . Accessed 25 Feb 2015.Fish, R., Lobley, M., & Winter, M. (2013). A license to produce? Farmer interpretations of the new food security agenda. Journal of Rural Studies, 29, 40–49.Grando, S., & Colombo, L. (2015). National Report. Italy. WP2 report Transmango EU-FP7.GREENPEACE (2014). Alimentos bajo amenaza. Valor económico de la polinización y vulnerabilidad de la agricultura española ante el declive de las abejas y otros polinizadores. Madrid: Greenpeace.Hertel, T. W. (2015). The challenges of sustainably feeding a growing planet. Food Security, 7, 185–198.Hispacoop (2012). Estudio sobre desperdicio de alimentos en los hogares. Madrid: Confederación Española de Cooperativas de Consumidores y Usuarios.Lang, T., & Heasman, M. (2004). Food wars. The global battle for mouths, Minds and Markets. London: Earthscan.Lawrence, G., & McMichael, P. (2012). The question of food security. International Journal of Sociology of Agriculture & Food, 19(2), 135–142.MAGRAMA. (2014). La balanza commercial agroalimentaria en 2013. Madrid.Maye, D., & Kirwan, J. (2013). Food security: a fractured consensus. Journal of Rural Studies, 29, 1–6.McKeon, N. (2015). Food security governance: empowering communities, regulating corporations. New York: Routledge.Mooney, P. H., & Hunt, S. A. (2009). Food security: the elaboration of contested claims to a consensus frame. Rural Sociology, 74(4), 469–497.Moreno, O. (2013). Reproducing productivism in Spanish agricultural systems. In D. Ortiz, A. Moragues, & E. Arnalte (Eds.), Agriculture in Mediterranean Europe: between old and new paradigms. Research in rural sociology and development (pp. 121–147). Bingley: Emerald Group Publishing Limited.Muñoz, C., & Sosvilla, S. (2014). Alimentamos el futuro. Informe económico 2013. Madrid: FIAB.OECC - Oficina Española de Cambio Climático (2006). Plan Nacional de Adaptación al Cambio Climático. Madrid.OECC-UCLM (2005). Evaluación Preliminar de los Impactos en España por Efecto del Cambio Climático. Madrid: MAGRAMA.Pangaribowo, E. H., Gerber, N., & Torero, M. (2013). Food and Nutrition Security Indicators: A Review. ZEF working paper no 108. Bonn: ZEF.Sáez-Almendros, S., Obrador, B., Bach-Faig, A., & Serra-Majem, L. (2013). Environmental footprints of Mediterranean versus Western dietary patterns: beyond the health benefits of the Mediterranean diet. Environmental Health, 12, 118.Shepherd, B. (2012). Thinking critically about food security. Security Dialogue, 43(3), 195–212.Sineiro, F. (2012). Situación actual, retos y perspectivas del vacuno de leche. Available at http://www.eumedia.es/portales/files/documentos/2-FSineiro.pdf . Accessed 19 Nov 2015.Van Gorp, B. (2007). The constructionist approach to framing: bringing culture back. Journal of Communication, 57, 60–78.Van Gorp, B., & van der Goot, M. J. (2012). Sustainable food and agriculture: Stakeholder’s frames. Communication, Culture & Critique, 5, 127–148.Vidal, R., Moliner, E., Pikula, A., Mena-Nieto, A., & Ortega, A. (2015). Comparison of the carbon footprint of different patient diets in a Spanish hospital. Journal of Health Services Research & Policy, 20(1), 39–44

Foodways in transition: food plants, diet and local perceptions of change in a Costa Rican Ngäbe community

Background Indigenous populations are undergoing rapid ethnobiological, nutritional and socioeconomic transitions while being increasingly integrated into modernizing societies. To better understand the dynamics of these transitions, this article aims to characterize the cultural domain of food plants and analyze its relation with current day diets, and the local perceptions of changes given amongst the Ngäbe people of Southern Conte-Burica, Costa Rica, as production of food plants by its residents is hypothesized to be drastically in recession with an decreased local production in the area and new conservation and development paradigms being implemented. Methods Extensive freelisting, interviews and workshops were used to collect the data from 72 participants on their knowledge of food plants, their current dietary practices and their perceptions of change in local foodways, while cultural domain analysis, descriptive statistical analyses and development of fundamental explanatory themes were employed to analyze the data. Results Results show a food plants domain composed of 140 species, of which 85 % grow in the area, with a medium level of cultural consensus, and some age-based variation. Although many plants still grow in the area, in many key species a decrease on local production–even abandonment–was found, with much reduced cultivation areas. Yet, the domain appears to be largely theoretical, with little evidence of use; and the diet today is predominantly dependent on foods bought from the store (more than 50 % of basic ingredients), many of which were not salient or not even recognized as ‘food plants’ in freelists exercises. While changes in the importance of food plants were largely deemed a result of changes in cultural preferences for store bought processed food stuffs and changing values associated with farming and being food self-sufficient, Ngäbe were also aware of how changing household livelihood activities, and the subsequent loss of knowledge and use of food plants, were in fact being driven by changes in social and political policies, despite increases in forest cover and biodiversity. Conclusions Ngäbe foodways are changing in different and somewhat disconnected ways: knowledge of food plants is varied, reflecting most relevant changes in dietary practices such as lower cultivation areas and greater dependence on food from stores by all families. We attribute dietary shifts to socioeconomic and political changes in recent decades, in particular to a reduction of local production of food, new economic structures and agents related to the State and globalization

Nutritional valuation of schoolchildren from three Ibero-American countries: A comparative analysis of the references proposed by International Obesity Task Force (IOTF) and World Health Organization (WHO)

Introducción: El índice de masa corporal (IMC) resulta un indicador útil para valorar la condición nutricional en la infancia y adolescencia. Si bien no existe consenso respecto a los valores o puntos de corte de IMC que deben utilizarse para la diagnosis del sobrepeso, la obesidad o la insuficiencia ponderal, las referencias propuestas por la Organización Mundial de la Salud (OMS) y la International Obesity Task Force (IOTF) son las más aceptadas. No obstante, existen discrepancias importantes en los resultados obtenidos en función de una u otra referencia. Objetivo: Analizar y comparar la condición nutricional de una muestra internacional a partir del IMC, mediante la aplicación simultánea de las referencias recomendadas por la IOTF y la OMS. Métodos: Se calculó el IMC de 1289 escolares de 10 a 13 años de México, Venezuela y España. A cada niño le fue atribuida una categoría nutricional (bajo peso, normopeso, sobrepeso y obesidad) utilizando el criterio de la IOTF (puntos de corte equivalentes a 18,5; 25 y 30 en adultos) y OMS (-1 DE: bajo peso + 1 DE: sobrepeso y +2 DE: obesidad). Las prevalencias de estado nutricional obtenidas por cada criterio fueron comparadas mediante la prueba de Chi-Cuadrado. Resultados: El porcentaje de escolares en cada una de las categorías nutricionales varió significativamente en función de la referencia empleada. La prevalencia de malnutrición por exceso o por defecto fue, en ambos sexos y en los tres países, superior al emplear los parámetros OMS. La referencia OMS evidenció un 10,9% menos de niños normonutridos y un 13,1% más de malnutridos que la IOTF. Discusión: Los resultados de esta investigación permiten inferir que la referencia propuesta por la OMS resulta ser más “preventiva” al momento de identificar individuos malnutridos. Se subraya la importancia de especificar los criterios empleados para la determinación del estado nutricional en los estudios de carácter epidemiológico, así como de contrastar las referencias empleadas para el diagnóstico. Conclusiones: Las referencias OMS para IMC sobrestiman la prevalencia de bajo peso, sobrepeso y obesidad en relación a los puntos de corte propuestos por el IOTF para el diagnóstico de la malnutrición.Introduction: Body Mass Index (BMI) is a useful tool for assessing nutritional status in childhood and adolescence. Although there is no consensus on BMI values or cutoffs to be used for the diagnosis of overweight, obesity and underweight references proposed by World Health Organization (WHO) and International Obesity Task Force (IOTF) are the most accepted. However, there are significant discrepancies in the results obtained in terms of either reference. Objective: To analyze and compare the nutritional status of an international sample from IMC, by simultaneous application of IOTF and WHO recommended references. Methods: 1289 schoolchildren’s BMI between 10 and 13 years of Mexico, Venezuela and Spain was estimated. Each child was assigned a nutritional category (underweight, normal weight, overweight and obese) using the IOTF criteria (points cut equivalent to 18,5, 25 and 30 in adults) and WHO (-1 SD: low weight +1 DE: overweight and +2 SD: obesity). The prevalence of nutritional status of each criterion was compared using the Chi-square test. Results: The percentage of students in each of the nutritional categories mottled significantly depending on the reference used. The prevalence of excess or defect malnutrition, in both sexes and in all three countries, was exceeded using the WHO parameters. WHO reference showed 10,9% less than well-nourished children and 13,1 % more malnourished than the IOTF. Discussion: The results of this research allow inferring that the reference proposed by WHO appears to be more “protecting” when identifying malnourished individuals. The importance of specifying the criteria for determination of nutritional status in epidemiologic studies, as well as to contrast the references used for diagnosis, is emphasized. Conclusions: The WHO BMI references overestimate the prevalence of underweight, overweight and obesity in relation to the cutoff points proposed by the IOTF for diagnosing malnutrition.Instituto de Genética VeterinariaFacultad de Ciencias Naturales y Muse

Nutritional valuation of schoolchildren from three Ibero-American countries: A comparative analysis of the references proposed by International Obesity Task Force (IOTF) and World Health Organization (WHO)

Introducción: El índice de masa corporal (IMC) resulta un indicador útil para valorar la condición nutricional en la infancia y adolescencia. Si bien no existe consenso respecto a los valores o puntos de corte de IMC que deben utilizarse para la diagnosis del sobrepeso, la obesidad o la insuficiencia ponderal, las referencias propuestas por la Organización Mundial de la Salud (OMS) y la International Obesity Task Force (IOTF) son las más aceptadas. No obstante, existen discrepancias importantes en los resultados obtenidos en función de una u otra referencia. Objetivo: Analizar y comparar la condición nutricional de una muestra internacional a partir del IMC, mediante la aplicación simultánea de las referencias recomendadas por la IOTF y la OMS. Métodos: Se calculó el IMC de 1289 escolares de 10 a 13 años de México, Venezuela y España. A cada niño le fue atribuida una categoría nutricional (bajo peso, normopeso, sobrepeso y obesidad) utilizando el criterio de la IOTF (puntos de corte equivalentes a 18,5; 25 y 30 en adultos) y OMS (-1 DE: bajo peso + 1 DE: sobrepeso y +2 DE: obesidad). Las prevalencias de estado nutricional obtenidas por cada criterio fueron comparadas mediante la prueba de Chi-Cuadrado. Resultados: El porcentaje de escolares en cada una de las categorías nutricionales varió significativamente en función de la referencia empleada. La prevalencia de malnutrición por exceso o por defecto fue, en ambos sexos y en los tres países, superior al emplear los parámetros OMS. La referencia OMS evidenció un 10,9% menos de niños normonutridos y un 13,1% más de malnutridos que la IOTF. Discusión: Los resultados de esta investigación permiten inferir que la referencia propuesta por la OMS resulta ser más “preventiva” al momento de identificar individuos malnutridos. Se subraya la importancia de especificar los criterios empleados para la determinación del estado nutricional en los estudios de carácter epidemiológico, así como de contrastar las referencias empleadas para el diagnóstico. Conclusiones: Las referencias OMS para IMC sobrestiman la prevalencia de bajo peso, sobrepeso y obesidad en relación a los puntos de corte propuestos por el IOTF para el diagnóstico de la malnutrición.Introduction: Body Mass Index (BMI) is a useful tool for assessing nutritional status in childhood and adolescence. Although there is no consensus on BMI values or cutoffs to be used for the diagnosis of overweight, obesity and underweight references proposed by World Health Organization (WHO) and International Obesity Task Force (IOTF) are the most accepted. However, there are significant discrepancies in the results obtained in terms of either reference. Objective: To analyze and compare the nutritional status of an international sample from IMC, by simultaneous application of IOTF and WHO recommended references. Methods: 1289 schoolchildren’s BMI between 10 and 13 years of Mexico, Venezuela and Spain was estimated. Each child was assigned a nutritional category (underweight, normal weight, overweight and obese) using the IOTF criteria (points cut equivalent to 18,5, 25 and 30 in adults) and WHO (-1 SD: low weight +1 DE: overweight and +2 SD: obesity). The prevalence of nutritional status of each criterion was compared using the Chi-square test. Results: The percentage of students in each of the nutritional categories mottled significantly depending on the reference used. The prevalence of excess or defect malnutrition, in both sexes and in all three countries, was exceeded using the WHO parameters. WHO reference showed 10,9% less than well-nourished children and 13,1 % more malnourished than the IOTF. Discussion: The results of this research allow inferring that the reference proposed by WHO appears to be more “protecting” when identifying malnourished individuals. The importance of specifying the criteria for determination of nutritional status in epidemiologic studies, as well as to contrast the references used for diagnosis, is emphasized. Conclusions: The WHO BMI references overestimate the prevalence of underweight, overweight and obesity in relation to the cutoff points proposed by the IOTF for diagnosing malnutrition.Instituto de Genética VeterinariaFacultad de Ciencias Naturales y Muse