[ASSOCIATION BETWEEN HEALTH RELATED QUALITY OF LIFE, BODYWEIGHT STATUS (BMI) AND PHYSICAL ACTIVITY AND FITNESS LEVELS IN CHILEAN ADOLESCENTS]. / ASOCIACIÓN ENTRE LA CALIDAD DE VIDA RELACIONADA CON LA SALUD, EL ESTADO NUTRICIONAL (IMC) Y LOS NIVELES DE ACTIVIDAD FÍSICA Y CONDICIÓN FÍSICA EN ADOLESCENTES CHILENOS.

AIM: the objective of this study was to analyze the potential relationships between Health Related Quality of Life (HRQoL) with weight status, physical activity (PA) and fitness in Chilean adolescents in both, independent and combined analysis. METHOD: a sample of 767 participants (47.5% females) and aged between 12 and 18 (mean age 15.5) was employed. All measurements were carried out using selfreported instruments and Kidscreen-10, iPAQ and IFIS were used to assess HRQoL, PA and Fitness respectively. One factor ANOVA and linear regression models were applied to analyze associations between HRQoL, weight status, PA and fitness using age and sex as confounders. RESULTS: body mass index, level of PA and fitness were independently associated with HRQoL in Chilean adolescents. However, the combined and adjusted by sex and age analysis of these associations showed that only the fitness was significantly related with HRQoL. CONCLUSION: general fitness is associated with HRQoL independently of sex, age, bodyweight status and level of PA. The relationship between nutritional status and weekly PA with HRQoL are mediated by sex, age and general fitness.

Objetivos: el objetivo del presente estudio fue analizar las posibles relaciones entre la Calidad de Vida Relacionada con la Salud (CVRS) con el estado nutricional y los niveles de Actividad Física (AF) y Condición Física (CF) en adolescentes chilenos, de manera independiente e interactiva. Método: se utilizó una muestra de 767 participantes (47,5% chicas) con edades comprendidas entre los 12 y los 18 años de edad (edad media 15,5 años). Todas las medidas utilizadas se obtuvieron mediante instrumentos auto- administrados. Se utilizó el Kidscreen-10, iPAQ e IFIS para evaluar la CVRS, la AF y la CF, respectivamente. Se realizaron análisis de ANOVA de un factor y modelos de regresión lineal para analizar las asociaciones entre la CVRS, el estado nutricional, la AF y la CF utilizando la edad y el sexo como variables confusoras. Resultados: se ha encontrado una asociación independiente del Índice de Masa Corporal, el nivel de AF y de CF con el nivel de CVRS de adolescentes chilenos. Sin embargo, al analizar esta asociación de forma combinada y ajustada por sexo y edad tan solo el nivel de CF general se asocia de forma significativa con la CVRS. Conclusión: el nivel de CF general se asocia con la CVRS en adolescentes chilenos independientemente del sexo, la edad, el estado nutricional y el nivel de AF. La relación entre el estado nutricional y el nivel de AF semanal con la CVRS están mediadas por el sexo, la edad y el nivel de CF general.

[Association between dietary habits and the presence of overweight/obesity in a sample of 21,385 chilean adolescents]. / ASOCIACIÓN ENTRE LOS HÁBITOS DIETÉTICOS Y LA PRESENCIA DE SOBREPESO/OBESIDAD EN UNA MUESTRA DE 21.385 ADOLESCENTES CHILENOS.

AIM: The main aim of the present study was to explore the potential associations between dietary habits and the presence of overweight and obesity in Chilean adolescents. METHODS: For the present study dietary habits of 21,385 Chilean students were analyzed and weight and height assessed, in order to determine potential associations between eating patterns and body mass index (BMI) values. RESULTS: The majority of participants have lunch and a snack in the afternoon every day a week (81% and 71.2%, respectively), although only a 59.5% have breakfast every day and a 22% have dinner every night. To have breakfast is common for thin and normal weight subjects, but only a half of overweight and obese individuals usually have it. The obese is the group having less dairy products. A 50.2% of all subjects have legumes once or never in a week. Around a 15% have sweets all days and nearly a 50% of all the participants consume fizzy drinks every day of the week. Interestingly, having breakfast was found to be associated with less truancy. CONCLUSIONS: Nutritional education strategies should be carried out within students in Chile, since inadequate dietary habits are related to the higher values of BMI.

Objetivos: El principal objetivo del presente trabajo fue evaluar las posibles asociaciones entre los hábitos dietéticos y la presencia de sobrepeso y obesidad en adolescentes Chilenos. Método: Para este trabajo se analizaron los hábitos dietéticos de 21.385 estudiantes Chilenos y se determinaron el peso y la talla, con el fin de explorar posibles asociaciones entre los patrones de alimentación y los valores de índice de masa corporal (IMC). Resultados: La mayoría de los participantes realiza la toma del almuerzo (81%) y de la merienda (71,2%) todos los días de la semana. Sólo el 59,5% de los encuestados toma desayuno cada día y un 22% cena todas las noches. Desayunar es común entre los sujetos delgados y con peso normal, pero únicamente la mitad de los individuos con sobrepeso u obesidad desayuna habitualmente. Los obesos son el grupo que consume menos productos lácteos. Un 50,2% de todos los participantes nunca toma legumbres o lo hace una vez por semana. En torno a un 15% toma dulces todos los días y casi la mitad de los encuestados ingiere bebidas carbonatadas cada día de la semana. Además, tomar desayuno de forma habitual se asoció inversamente con el absentismo escolar. Conclusión: Se necesitan llevar a cabo estrategias de educación nutricional entre los estudiantes chilenos, ya que los hábitos dietéticos inadecuados se encuentran asociados con valores más elevados de IMC.

The protein type within a hypocaloric diet affects obesity-related inflammation: the RESMENA project.

OBJECTIVES: The aim of this study was to compare the effect of two energy-restricted, differing with regard to protein content, on the inflammation state of obese individuals with features of metabolic syndrome. METHODS: Ninety-six participants completed an 8-wk randomized intervention trial that compared the RESMENA diet (-30% energy, with 30% energy from protein) with a control diet (-30% energy, with 15% energy from protein) that was based on American Heart Association criteria. RESULTS: The mean body weight losses were 7.09 ± 0.82 kg and 6.73 ± 0.71 kg, respectively, with no differences seen between the groups. The endpoint inflammation score-which was based on high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-α, and plasminogen activator inhibitor-1 levels-was significantly lower (P = 0.012) in the low-protein group (6.81 ± 2.32 versus 7.94 ± 1.94). The linear regression analyses revealed that total protein intake was positively associated with inflammation (P = 0.007) as well as with animal protein (P = 0.025) and meat protein (P = 0.015), but neither vegetable- nor fish-derived proteins were found to influence inflammatory status. CONCLUSIONS: Our results suggest that the type of protein consumed (more than the total protein consumed) within an energy-restricted diet influences the inflammation status associated with obesity-related comorbidities.

Association between circulating irisin levels and the promotion of insulin resistance during the weight maintenance period after a dietary weight-lowering program in obese patients.

OBJECTIVE: Weight regain is associated with the promotion of insulin resistance. The newly discovered myokine irisin, which was proposed to be involved in the management of insulin sensitivity, could play a role in this process. This study aimed to investigate the association between irisin and reduced insulin sensitivity induced by weight regain. MATERIALS/METHODS: Insulin sensitivity was evaluated according to the homeostasis model assessment of insulin resistance (HOMA-IR) in 136 obese patients who followed an eight-week hypocaloric diet (30% reduced energy expenditure) to lose weight and was re-evaluated four or six months after treatment. Irisin plasma levels, as well as the levels of leptin, adiponectin, ghrelin and TNF-α, were quantified in a sub-cohort (n=73) from the initially studied patients at baseline (T0), at the diet endpoint (T1) and after the follow-up period (T2). RESULTS: After a successful dietary intervention to lose weight, 50% of the patients who regained the lost weight during the follow-up period were categorized as insulin resistant (HOMA-IR≥2.5) compared with only 25% of patients who maintained the weight loss (p=0.018). Importantly, in addition to the well-studied hormones leptin and adiponectin, irisin plasma levels were statistically associated with several risk factors for insulin resistance. Indeed, the increased risk of insulin resistance during the follow-up period was related to high irisin levels at baseline (odds ratio=4.2; p=0.039). CONCLUSIONS: Circulating irisin predicts the insulin resistance onset in association with weight regain. Therefore, irisin could be secreted as an adaptive response to counteract the deleterious effect of excess adiposity on glucose homeostasis.

Vitamin C in the treatment and/or prevention of obesity.

Obesity has emerged as one of the major health threats worldwide. Moreover, an excessive body fat accumulation, which defines this disease, could lead to several associated clinical manifestations such as cardiovascular events, type 2 diabetes, inflammation, and some types of cancer. The appearance of these co-morbidities has been often related to an unbalanced oxidative stress. Therefore, antioxidant-based treatments could be considered as interesting approaches to possibly counteract obesity fat accumulation complications. In this context, it has been observed that vitamin C intake (ascorbic acid) is negatively associated with the occurrence of several conditions such as hypertension, gallbladder disease, stroke, cancers, and atherosclerosis, and also with the onset of obesity in humans and animals. Among the possible beneficial effects of ascorbic acid on obesity-related mechanisms, it has been suggested that this vitamin may: (a) modulate adipocyte lipolysis; (b) regulate the glucocorticoid release from adrenal glands; (c) inhibit glucose metabolism and leptin secretion on isolated adipocytes; (d) lead to an improvement in hyperglycemia and decrease glycosylation in obese-diabetic models; and (e) reduce the inflammatory response. Possibly, all these features could be related with the outstanding antioxidant characteristics of this vitamin. Thus, the present article reviews the up-to-date evidence regarding in vitro and in vivo effects of vitamin C in obesity and its co-morbidities.

Short-term role of the dietary total antioxidant capacity in two hypocaloric regimes on obese with metabolic syndrome symptoms: the RESMENA randomized controlled trial.

BACKGROUND: Dietary strategies seem to be the most prescribed therapy in order to counteract obesity regarding not only calorie restriction, but also bioactive ingredients and the composition of the consumed foods. Dietary total antioxidant capacity (TAC) is gaining importance in order to assess the quality of the diet. METHODS: Ninety-six obese adults presenting metabolic syndrome (MetS) symptoms completed an 8-week intervention trial to evaluate the effects of a novel dietary program with changes in the nutrient distribution and meal frequency and to compare it with a dietary pattern based on the American Heart Association (AHA) guidelines.Anthropometric and biochemical parameters were assessed at baseline and at the endpoint of the study, in addition to 48-hours food dietary records. RESULTS: Both diets equally (p > 0.05) improved MetS manifestations. Dietary TAC was the component which showed the major influence on body weight (p = 0.034), body mass index (p = 0.026), waist circumference (p = 0.083) and fat mass (p = 0.015) reductions. Transaminases (ALT and AST) levels (p = 0.062 and p = 0.004, respectively) were associated with lower TAC values. CONCLUSION: RESMENA diet was as effective as AHA pattern for reducing MetS features. Dietary TAC was the most contributing factor involved in body weight and obesity related markers reduction. TRIAL REGISTRATION: http://www.clinicaltrials.gov; NCT01087086.