RESUMEN Introducción: La lactancia materna (LM) es un factor protector contra la obesidad infantil; sin embargo, los mecanismos a través de los cuales ejerce este efecto aún no están claros. El objetivo fue describir los mecanismos asociados al efecto protector que ejerce la lactancia materna contra la obesidad infantil. Métodos: Se utilizaron los buscadores PUBMED, SCOPUS, Cochrane Library y Scielo para desarrollar una revisión descriptiva de la evidencia científica. Las palabras clave fueron: lactancia materna, obesidad, mecanismo y dieta. Se revisaron artículos en español e inglés, desde 1977 hasta el 2020. Resultados: El efecto protector de la LM contra la obesidad infantil está dado por una combinación de varios mecanismos, se destaca su composición nutricional y el aporte de sustancias bioactivas, algunas de ellas reguladoras de la ingesta energética. Los lactantes que reciben LM por más tiempo seleccionan alimentos más saludables en etapa preescolar, independiente de factores sociodemográficos. También han sido descritos efectos en la adiposidad, el control del peso corporal y la ingesta energética mediante regulación de la programación epigenética y de la microbiota intestinal. Conclusión: La LM es un proceso único, que interacciona de forma compleja con factores del crecimiento y desarrollo de los lactantes y preescolares. Su rol protector contra la obesidad ha sido asociado a diversos mecanismos. Sin embargo, se requiere de nuevas investigaciones para comprender los alcances que puede presentar la LM en la etapa pediátrica y su rol en la prevención de la obesidad.

ABSTRACT Background and aim: Breastfeeding (BF) is a protective factor against childhood obesity; however, the mechanisms associated with this effect have not yet been elucidated. This study aimed to describe the mechanisms related to the protective effect of breastfeeding against childhood obesity. Methods: A search on PUBMED, SCOPUS, Cochrane Library and SCIELO databases was carried out to develop a descriptive review of the scientific evidence. The key words were breastfeeding; obesity; mechanism and diet. Articles were reviewed in Spanish and English from 1977 to 2020. Results: The protective effect of BF against childhood obesity is given by a combination of several mechanism. Its nutritional composition and the contribution of bioactive substances stand out, some of them regulated by the energy intake. Infants who are breastfed choose healthier foods in preschool, regardless of sociodemographic factors. Effects on adiposity, control of body weight and energy intake have also been described by epigenetic regulation programming and the intestinal microbiota. Conclusion: BF is a unique process that interacts in a complex way with infants and preschoolers’ growth and developmental factors Its protective role against childhood obesity has been associated with various mechanisms. New research is still required to understand the implications of BF in pediatric age and its role in preventing obesity.

Abstract Introduction The average life expectancy, as well as the prevalence of Type 2 diabetes (T2D), is increasing worldwide. Population-based studies have demonstrated that the duration of T2D has been associated with cognitive impairment. However, despite the high prevalence of T2D and cognitive impairment in Chile, the association between years with T2D and suspicion of cognitive impairment has not yet been investigated. The objective of this study was to investigate the association between duration of T2D and suspicion of cognitive impairment in Chilean older adults. Material and Methods 1,040 older adults aged ≥60 years from the Chilean National Health Survey (2009-2010) were included. Suspicion of cognitive impairment was assessed by the abbreviated Mini-Mental State Examination (MMSE). The number of years with T2D was self-reported and categorised into four groups. Poisson Regression analysis was used to assess the association between altered MMSE and the number of years with DM2, adjusted by potential confounders including socio-demographic, lifestyle, adiposity and health-related factors. Results When the analyses were adjusted for socio-demographic factors, people who had T2D for 15 to 24 and ≥25 years had 2.2-times (95%CI: 1.07; 3.33) and 5.8-times (95%CI: 3.81; 11.0) higher relative risk (RR) of cognitive impairment, compared to those without T2D. When the analyses were additionally adjusted for lifestyle and health-related covariates, the RR for cognitive impairment was 1.76-times (95%CI: 1.02; 2.50) and 4.54-times (95%CI: 2.70; 6.38) higher for those who had T2D for 14-24 years and ≥25 years, respectively. Conclusions Number of years with T2D was associated with suspicion of cognitive impairment. A longer duration of T2D was associated with a higher likelihood of cognitive impairment in the Chilean older population, independently of confounder factors included in the study.

RESUMEN Introducción: La esperanza de vida está aumentando en todo el mundo, así como la diabetes tipo 2 (DM2). Estudios poblacionales han demostrado que la duración de la DM2 se ha asociado con el deterioro cognitivo. Sin embargo, a pesar de la alta prevalencia de DM2 y deterioro cognitivo en Chile, aún no se ha investigado la asociación entre años con DM2 y la sospecha de deterioro cognitivo. El objetivo del estudio fue investigar la asociación entre la duración de la DM2 y la sospecha de deterioro cognitivo en personas mayores chilenas. Material y Métodos Participaron 1.040 personas ≥60 años de la Encuesta Nacional de Salud de Chile (2009-2010). El deterioro cognitivo se evaluó mediante el Mini Examen del Estado Mental abreviado (MMSE). El número de años con DM2 fue categorizado en cuatro grupos. Para valorar la asociación entre MMSE alterado y el número de años con DM2, se utilizó una regresión de Poisson, ajustados a posibles factores de confusión sociodemograficos, de estilos de vida, adiposidad y salud. Resultados Cuando se ajustaron los análisis por factores sociodemográficos, las personas con 15 a 24 y ≥25 años con DM2 presentaron 2,2 veces (IC95%: 1,07; 3,33) y 5,8 veces (IC95%: 3,81; 11,0) riesgo relativo (RR) de deterioro cognitivo, en comparación con aquellas sin DM2. Luego de ajustar adicionalmente los análisis para las covariables relacionadas con el estilo de vida y la salud, el RR para deterioro cognitivo fue 1,76 veces (IC95%: 1,02; 2,50) y 4,54 veces (IC95%: 2,70; 6,38) más alto para aquellas personas con 14-24 y ≥25 años de DM2. Conclusiones Se asoció el número de años con DM2 con la sospecha de deterioro cognitivo. Una mayor duración de la DM2 se asoció con una mayor probabilidad de deterioro cognitivo en la población mayor chilena.

Background: Adiposity and education are two independent risk factors for type 2 diabetes (T2D). However, there is limited evidence whether both education and adiposity are associated with T2D in an additive manner in the Chilean population. Aim: To investigate the joint association between adiposity and education with T2D in the Chilean adult population. Material and Methods: Analysis of data of the Chilean National Health Survey 2016-2017, which included 5,033 participants with a mean age of 43 years, (51% women). Poisson regression analyses with robust standard error were used to investigate the joint association of the education level and general and central adiposity with T2D. The results were reported as Prevalence Ratio and their 95% confidence intervals (PR, 95% CI). Results: Obesity was associated with a higher probability of having T2D in men than in women, however central adiposity was associated with a higher probability of having T2D in women than in men. Compared with men who had higher education (> 12 years) and had normal body weight, those with the same educational level and who were obese had 2.3-times higher probability of having T2D (PR: 2.35 [95% CI: 1.02; 5.39]). For women, having a low education and being obese was associated with 4.4-times higher probability of having T2D compared to those with higher education and normal body mass index (BMI) (PR: 4.47 [95% IC: 2.12; 9.24]). Similar results were observed when waist circumference was used as a marker of obesity rather than BMI. Conclusions: Women and men with higher BMI and low education had a higher risk of T2D. However, this risk was higher in women than in men.

Resumen Antecedentes: las conductas poco saludables, como baja actividad física, ayuno prolongado, con sumo de alimentos de alta densidad energética y baja ingesta de frutas y verduras repercuten en la salud. Objetivo: conocer los hábitos alimentarios de estudiantes del Campus San Andrés de la Universidad Católica de la Santísima Concepción, Región del Bío-Bío, Chile. Materiales y métodos: se aplicó la encuesta dicotómica “¿Es tu alimentación saludable?” en 350 estudiantes. Resulta dos: el 75 % de los encuestados tenía una alimentación no saludable o poco saludable, con mayor prevalencia en el rango etario entre 17-20 años (78 %). Se destaca el bajo consumo de frutas (<20 %), verduras (42 %) y agua (46 %), junto con una baja prevalencia de conductas saludables/responsables, como evitar alimentos azucarados (36 %) o embutidos (38 %) y revisar los etiquetados nutriciona les (37 %). Los hombres presentaron mayor consumo de pan, carnes blancas y agua (p<0,05), mientras que las mujeres declararon en mayor porcentaje evitar embutidos, revisar los etique tados nutricionales (p<0,01), preferir alimentos azucarados y comer de forma adecuada (p<0,05). Conclusiones: los estudiantes universitarios encuestados presentan hábitos alimentarios poco salu dables, asociados principalmente a bajo consumo de frutas y verduras.

Abstract Background: Unhealthy behaviors such as low physical activity, prolonged fasting, consumption of energy-dense foods and low consumption of fruits and vegetables have repercussions on health. Objective: To understand the dietary habits of students from the San Andres campus of the Universidad Católica de la Santísima Concepción, in the Bío-Bío region of Chile. Materials and Methods: The dichotomous survey, “Is your diet healthy?” was applied to 350 students. Results: The survey revealed that 75% of the students had an unhealthy diet, with a greater prevalence in those between 17-20 years of age (78%). It also demonstrated a low consumption of fruits (<20%), vegetables (42%) and water (46%), together with a low prevalence of healthy/responsible behaviors like avoiding sugary foods (36%), avoiding processed meats (38%), and reading nutrition labels (37%). Men reported a greater consumption of bread, white meats, and water (p<0,05), while women reported the greatest percentages of avoiding processed meats, read ing nutrition labels (p<0,01), and preferred sugary foods and eating properly (p<0,05). Conclusion: The surveyed university students presented poor dietary habits, primarily associated with low consumption of fruits and vegetables.

ABSTRACT Objective: To study the association of SLC16A11 gene variants with obesity and metabolic markers in nondiabetic Chilean adults. Materials and methods: This cross-sectional study included 263 non-diabetic adults. The genotype of the rs75493593 polymorphism of SLC16A11 gene was performed by real-time PCR. It's association with adiposity markers (body weight, BMI, waist circumference and fat mass percentage), metabolic markers (glucose, insulin, HOMAIR, leptin, total cholesterol, LDLc, HDLc, triglycerides, ALT, GGT and hsCRP) and blood pressure was analyzed by linear regression. Results: The minor allele (T) of the SLC16A11 gene (rs75493593) has a frequency of 29.7% among Chileans. Risk genotypes (GT and TT) were associated with a significant 1.49 mU/l increase in plasmatic insulin for each copy of the minor allele (95% CI: 0.12, 2.87, p < 0.05). This association remained significant after adjusting for socio-demographic variables, physical activity and smoking (1.36 mU/l, 95% CI: 0.16, 2.58 p < 0.05), but was lost when BMI was included as a confounding factor. Higher BMI was also significantly associated with polymorphic genotypes in SLC16A11, independent of socio-demographic variables. Conclusion: The minor allele of the SLC16A11 gene (T) is highly prevalent among Chileans and is associated with increased insulin and BMI in nondiabetic individuals. These findings suggest that the genetic variant in SLC16A11 is not only associated with type 2 diabetes as previously shown in Mexicans, but is also related to early metabolic alterations in healthy subjects that may lead to type 2 diabetes.

Background: Depression has been previously associated with cognitive impairment in high income country populations. However, its association in the Chilean population has not been investigated. Aim: To investigate the association between depression and cognitive impairment. Material and Methods: Data from 1384 Chilean adults aged > 60 years, participating in the National Health Survey 2009-2010 was analyzed. Cognitive impairment was assessed using the Mini Mental Examination score. The medical diagnosis of depression was self-reported. The association between depression and cognitive impairment was assessed using a logistic regression. Results: Depression was positively associated with cognitive impairment. However, the magnitude of the association was higher in men (Odds ratio (OR) = 4.02 [95% confidence intervals (CI): 1.44; 6.61], p < 0.01]) than in women (OR = 2.23 [95%CI: 1.03; 3.43], p = 0.04). Older adults who were diagnosed for the first time with depression after 65 years of age, showed a stronger association with cognitive impairment (OR = 6.65 [95% CI: 2.39; 10.9], p < 0.01) than those diagnosed before 55 years. Conclusions: Our study confirms the association between depression and cognitive impairment. Further research is needed to elucidate the nature and potential mechanisms that link depression with cognitive impairment.

Background: Sugar intake is a risk factor for the development of obesity. Aim: To investigate the association between total sugar intake and obesity markers in Chilean adults. Material and Methods: This cross-sectional study included 396 participants of the GENADIO study. Anthropometric measurements (body weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio, and % body fat) were measured through standardized protocols. Total sugar intake was determined from a 7-days weighted food daily. Sugar intake expressed in g/day was categorized into quartiles. Results: Higher sugar intake was associated with a higher BMI, WC and HC but not with body fat %. One quartile increment in sugar intake was associated with 1.50 kg [95% confidence interval (CI): 0.49; 2.50] higher body weight, 0.34 kg/m2 [95% CI: 0.01; 0.69] higher BMI, 1.23 cm [95% CI: 0.11; 2.34] higher WC, 1.39 cm [95% CI: 0.28; 2.50] higher HC and 0.02 the waist-to-hip ratio [95% C: 0.01; 0.02]. Conclusions: Total sugar intake was associated with higher adiposity levels in these Chilean adults.

Abstract: Introduction: Obesity is considered a chronic inflammatory disease with an important genetic component. Although several studies have reported an association between the FTO (fat-mass associated gene) and adiposity in children, there is limited evidence in the Chilean population. Objective: To deter mine the association between the polymorphism rs9939609 of the FTO gene and markers of adipo sity in Chilean children. Patients and Method: Cross-sectional study which included 361 children aged between 6 and 11 years (50% were girls). Between March and June 2008, clinical data and blood sample collection was carried out. The rs9939609 single-nucleotide polymorphism (SNP) of the FTO gene, was determined using the genomic DNA extracted from leukocytes, using the QIAamp DNA Blood Mini Kit (Qiagen GmbH, Hilden, Germany).The adiposity markers included were body mass index (BMI), waist circumference (WC), body fat, and WC/H index; which were later compared adjusted by sex, age, and Tanner stage. Linear regression analyses were conducted to detect the association between the polymorphism and obesity markers. Results: After adjusting the models by age, sex, and Tanner stage, we found a significant association between the polymorphism and markers of adiposity. For each extra copy of the risk allele, we found an increase of 2.47 kg body weight (95% CI: 1.39-3.55); 1.06 kg/m2 BMI (95% CI: 0.56-1.54); 2.55 cm WC, (95% CI: 1.26-3.85); and 1.98% body fat (95% CI: 0.78-3.19). When converting adiposity markers to z-score, we found that WC/height index shows the strongest association with the risk allele FTO. Conclusion: This study supports the association between the rs9939609 SNP of the FTO gene and overall and central adiposity markers in Chilean children.

Resumen: Introducción: La obesidad es una enfermedad inflamatoria donde la genética determina cierto nivel de riesgo. Aun cuando existen estudios que reportan asociación entre polimorfismos de FTO (fat-mass associated gene) y adiposidad, existe limitada evidencia en población infantil chilena. Objetivo: determinar la asociación entre el polimorfismo rs9939609 del FTO y marcadores de adiposidad en población in fantil chilena. Pacientes y Método: Estudio de corte transversal incluyó 361 participantes (de 6 a 11 años; 50% niñas). Los datos clínicos y la recolección de muestras de sangre se realizaron entre marzo y junio de 2008. El polimorfismo SNP (rs9939609), del gen FTO, se determinó utilizando ADN genómico extraído de leucocitos, utilizando el Mini Kit QIAamp DNA Blood (Qiagen GmbH, Hilden, Alemania). Los marcadores de adiposidad estudiados fueron, índice de masa corporal (IMC), masa grasa, perímetro de cintura (PC) y razón cintura/talla, y se compararon ajustados por sexo, edad y estadio de Tanner. La asociación entre el polimorfismo estudiado y los marcadores de obesidad se realizó mediante análisis de regresión lineal. Resultados: Al ajustar los marcadores por sexo, edad y estadío de Tanner se observó una asociación significativa entre el polimorfismo e indicadores de adi posidad. Por cada copia extra del alelo de riesgo se encontró un aumento de 2,47 kg de peso corporal, (IC 95%: 1,39-3,55); 1,06 kg/m2 de IMC, (IC 95%: 0,56-1,54); 2,55 cm de PC, (IC 95%: 1,26-3,85) y 1,98% de masa grasa, (IC 95%: 0,78-3,19). Al convertir los marcadores de adiposidad a z-score, la razón perímetro de cintura/talla arrojó la mayor asociación con el alelo de riesgo de FTO. Conclu sión: Este estudio indica asociación entre el polimorfismo rs9939609 del gen FTO con marcadores de adiposidad general y central en población infantil en Chile.

ABSTRACT The aim was to review the evidence supporting the possible health benefits for obesity of breastfeeding versus formula feeding in infants. The search for studies addressing this topic was conducted in PubMed, Web of Science and Scielo databases. “Breastfeeding”, “formula feeding” and “obesity” were the keywords used in the search. Only studies with a full version of the manuscript were included. The evidence analyzed indicated that children fed exclusively through breastfeeding reported low levels of overweight and obesity in comparison to those fed by infant milk formulas. To conclude, exclusive breastfeeding until the sixth month of life, and supplementation with solid (non-dairy) food until two years and more, is the gold standard and could protect against childhood obesity and its associated comorbidities in adult life.

RESUMEN El objetivo del trabajo fue analizar el posible efecto protector de la lactancia materna respecto a la obesidad infantil versus fórmulas lácteas. Se consultaron las bases de datos PubMed, Web of Science y Scielo, considerándose los artículos más actualizados sobre el tema. La evidencia analizada señala que los menores alimentados con lactancia materna exclusiva reportan bajos niveles de sobrepeso y obesidad, a diferencia de los alimentados con fórmulas lácteas infantiles. Se concluye que la lactancia materna exclusiva, hasta el sexto mes de vida del lactante, y complementada con alimentación solida (no láctea) hasta los dos o más años, es recomendada y podría proteger contra la obesidad infantil y sus comorbilidades asociadas en la vida adulta.

ABSTRACT Chile has one of the highest rates of obesity worldwide. Deaths attributed to obesity are likely to increase to 204,000 by 2030. There will be also a higher economic burden associated with this disease. There are many factors associated with obesity; however, it is known that one of the most effective strategies to decrease its prevalence is reducing modifiable risk factors, such as improving dietary patterns, performing physical activity, avoiding smoking and drinking alcohol as well as improving mental health. Nevertheless, how to make realize these changes is one of the biggest challenges. In this context, the aim of this literature review, chapter 2, was to investigate the main modifiable risk factors, with emphasis on individual factors, associated with the development of obesity in Chile: from a global view to the Chilean context.

RESUMEN Chile tiene una de las tasas de obesidad más altas del mundo. Se estima que para el año 2030 las muertes atribuidas a esta enfermedad alcanzarían a 204 mil personas, incrementándose además los costos económicos asociados a esta patología. Las causas y los factores de riesgo asociados al desarrollo de obesidad son diversos. Sin embargo, existe consenso que una de las maneras más eficaces de prevenir y/o disminuir su prevalencia es abordando los factores de riesgo modificables, a través del fomento de hábitos de vida saludable con un enfoque integral, centrados en la alimentación saludable, práctica de actividad física, prevención del tabaquismo y consumo de alcohol, como también en el cuidado de la salud mental del individuo. No obstante, el desafío es cómo hacer realidad estos buenos propósitos. En este contexto, el objetivo de esta revisión, parte 2, fue investigar los principales factores modificables, con énfasis en los factores individuales, que han repercutido en el desarrollo de obesidad: desde una mirada global hasta el caso particular de Chile.

ABSTRACT Obesity is an inflammatory, chronic, recurrent and progressive disease with a multifactorial aetiology. More than 650 million people live with obesity across the globe, which represents a substantial physical, emotional and economic burden at all levels. Rapid urbanisation, economic growth and globalisation have deeply changed the lifestyles of the Chilean population and have worked in favour of an obesogenic environment. However, what factors have impacted the development of obesity in Chile? What has been the role of each one in the rise of its prevalence? In Chapter one of this literature review, we will discuss the main non- modifiable risk factors that have influenced its development, from the epidemiological transition that the country experienced in the 1970s to the related endocrine pathologies.

RESUMEN La obesidad es una enfermedad inflamatoria, crónica, recurrente, progresiva y de etiología multifactorial, que afecta a más 650 millones de personas en el mundo. La carga física, emocional y económica que genera la obesidad no solo guarda relación con sus manifestaciones clínicas, sino también por su impacto a nivel sistémico y a largo plazo. En Chile, el crecimiento económico, la urbanización y la globalización han modificado profundamente el modo de vivir de la población lo que ha favorecido un ambiente obesogénico. Sin embargo, ¿qué factores han repercutido en el desarrollo de obesidad en Chile? ¿cuál ha sido el rol de cada uno de estos factores en el aumento de la prevalencia de esta patología? En la parte 1 de esta revisión discutiremos los principales factores no modificables que han repercutido en su desarrollo, desde la transición epidemiológica que vivió el país en la década de los 70, hasta las patologías endocrinas relacionadas.