Ayuno intermitente como opción terapéutica para pacientes con sobrepeso y obesidad / Intermittent fasting as a therapeutic option for overweight and obese patients

Los regímenes basados en la restricción intermitente de la ingesta de alimentos, como el ayuno intermitente, pueden parecer novedosos pero constituyen en realidad una práctica milenaria. Muchas veces en nuestras consultas como médicos de familia los pacientes con problemas de sobrepeso u obesidad nos preguntan sobre estas prácticas y sus efectos en la salud. A partir de la viñeta clínica de uno de esos pacientes, revisamos la evidencia disponible sobre el tema y encontramos que la restricción intermitente puede ser una intervención eficaz para la disminución de peso, aunque sin diferencias significativas con respecto a la restricción continua. Para otros desenlaces analizados, como el riesgo cardiovascular, la evidencia no es tan clara. Si bien la restricción alimentaria intermitente puede ser una opción útil en para los pacientes que desean disminuir su peso, se necesitan más estudios para determinar la variante más adecuada, su duración óptima, la mejor frecuencia semanal y sus beneficios a largo plazo. (AU)

Intermittent dietary restriction, like intermittent fasting, may seem like a novel diet, but it's actually an age-old practice. Many times in our practice as family physicians, patients with overweight or obesity problems ask us about this practice and its effects on health. From the clinical vignette of one of our patients, we reviewed the available evidence on the subject and found that intermittent dietary restriction could be an effective intervention for weight loss, but without significant differences with respect to continuous caloric restriction. For other outcomes analyzed, such as cardiovascular risk, the evidence is not as clear. Al though intermittent dietary restriction may be a useful option in our patients, more studies are needed to determine which variant is the most appropriate, its optimal duration, weekly frequency, and long-term benefits. (AU)

Principales Estrategias de Intervención Nutricional realizadas en Chile en el decenio 2010-2020: avances y desafíos / Main Nutritional Intervention Strategies carried out in Chile in the 2010-2020 decade: progress and challenges

La alta prevalencia de obesidad en Chile, y su tendencia al aumento, constituye un problema de Salud Pública por su asociación con enfermedades crónicas no transmisibles. Durante la década 2010-2020, el estado de Chile implementó estrategias de intervención nutricional dirigidas a mantener o disminuir la prevalencia de obesidad. Regulaciones como la ley 20.606 sobre composición nutricional de los alimentos y su publicidad para modificar los entornos alimentarios, sistema elige vivir sano como modelo de gestión intersectorial constituido por políticas, planes y programas elaborados y ejecutados por distintos organismos del Estado, destinados a contribuir a generar hábitos y estilos de vida saludable y a prevenir y disminuir los factores y conductas de riesgo asociados a las enfermedades no transmisibles. A pesar de todos los esfuerzos, las encuestas poblacionales han demostrado que la obesidad continúa en aumento a lo largo del ciclo vital, por lo que es necesario fortalecer las estrategias existentes, pero con enfoque de determinantes sociales y de salud en todas las políticas, y a su vez mejorar los sistemas de evaluación de las estrategias implementadas en la población, midiendo su impacto además de su ejecución.

The high prevalence of obesity in Chile, and its increasing trend, constitutes a Public Health problem due to its association with chronic non-communicable diseases. During the 2010-2020 decade, the state of Chile implemented nutritional intervention strategies aimed at maintaining or reducing the prevalence of obesity. Regulations such as Law 20.606 on the nutritional composition of food and its advertising to modify food environments, Sistema chooses to live healthy System "EVS" Choose Healthy lifestyles as an intersectoral management model made up of policies, plans and programs prepared and executed by different State agencies, intended to contribute to healthy habits and lifestyles and to prevent and reduce risk factors and behaviors associated with non-communicable diseases. Despite all efforts, population surveys have shown that obesity continues to increase throughout the life cycle, which is why it is necessary to strengthen existing strategies, but with a focus on social and health determinants in all policies, since in turn, improve the evaluation systems of the strategies implemented in the population, measuring their impact, in addition to their implementation.

Interleukin-12 as a biomarker of the beneficial effects of food restriction in mice receiving high fat diet or high carbohydrate diet

The impact of food restriction (FR) during 56 days on serum levels of cytokines in mice fed a high-fat diet (HFD) or high-carbohydrate diet (HCD) were evaluated. The amount of food was reduced 50% for HFD-FR and HCD-FR groups compared to mice receiving free access to HFD (HFD group) or HCD (HCD group). We quantified the serum levels of basic fibroblast growth factor, granulocyte-macrophage colony-stimulating factor, inducible protein 10, interferon γ, interleukin 1α (IL-1α), IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17, keratinocyte chemoattractant, macrophage inflammatory protein-1α, monocyte chemotactic protein 1, monokine induced by IFN-γ, and tumor necrosis factor α. Only IL-12 levels were lower (P<0.05), for both HFD-FR (HFD-FR vs HFD) and HCD-FR (HCD-FR vs HCD). Therefore, IL-12 levels could be considered a biological marker of the beneficial effects of FR.

Experiencia del empleo sistemático de la dieta de muy bajo valor calórico para la optimización en el preoperatorio de cirugía bariátrica / Experience of the systemic use of the very low caloric value diet for the optimization in the preoperatory of bariatric surgery

Resumen Introducción: La cirugía bariátrica no está exenta de complicaciones. Para minimizar dichas complicaciones es importante optimizar al paciente antes de la cirugía. Dicha optimización se basa fundamentalmente en la realización de dieta preoperatoria. Dentro de los múltiples tipos de dietas, la dieta de muy bajo valor calórico (DMBVC) es cada vez más utilizada. El objetivo de este estudio es analizar los resultados del empleo de la DMBVC en el preoperatorio de cirugía bariátrica. Método: Estudio observacional de una serie de 100 casos en los que se empleó la DMBVC como optimización preoperatoria. Se analizaron el grado de cumplimiento de la dieta, la opinión de los pacientes, la pérdida de peso preoperatoria y las complicaciones postoperatorias. Resultados: La pérdida de peso preoperatoria media fue de 10,2 kg y la disminución media del IMC fue de 4,8. En cuanto al grado de seguimiento, el 68% refirió que la cumplió estrictamente, el 22% manifestó un buen grado de seguimiento con alguna transgresión ocasional, el 8% reportó un mal seguimiento y el 1% la abandonó precozmente. No se presentaron efectos adversos significativos. En cuanto a la técnica quirúrgica, en ningún caso el volumen hepático dificultó la cirugía, con un 0% de conversiones y un tiempo medio operatorio de 60 min. En el postoperatorio inmediato se registraron un 4% de sangrado y un 1% de reintervención por hemoperitoneo. Conclusiones: Las DMBVC son sencillas de utilizar, con escasos efectos adversos, bien toleradas durante un periodo limitado de tiempo, obteniendo una adecuada pérdida ponderal preoperatoria.

Abstract Introduction: Bariatric surgery may have some complications. To minimize such complications is important to optimize the patient before surgery. Such optimization is based primarily on the performance of preoperative diet. Among the many types of diets, very low caloric diet (VLCD) is increasingly used. The aim of this study is to analyze the results of the use of VLCD preoperative bariatric surgery. Method: Observational study of a series of 100 cases in which the DMBVC was used as a preoperative optimization. The degree of compliance with the diet, the opinion of patients, preoperative weight loss and postoperative complications were analyzed. Results: The mean preoperative weight loss was 10.2 kg and the average BMI decrease of 4.8. As for the degree of compliance, 68% said that the strictly fulfilled, 22% follow up with a good degree occasional transgression, mistracking 8% and 1% abandoned early. No significant adverse effects occurred. Regarding the surgical technique, in any case difficult surgery liver volume, with 0% conversion and an average operating time of 60 min. In the immediate postoperative period 4% cases of reoperation for bleeding and 1% hemoperitoneum were reported. Conclusions: DMBVC are simple to use, with few adverse effects, well tolerated for a limited period of time, obtaining adequate preoperative weight loss.

Metabolic profile and spontaneous physical activity modulation under short-term food restriction in young rats

Abstract AIMS The aim of this study was to investigate the effects of short-term food restriction (6-weeks) on metabolic profile and spontaneous physical activity (SPA) of young male Wistar rats. METHODS Thirty rats had their baseline SPA measured at 21 days-old and were separated into two groups at 28 days-old: Control (CG) and 50% of food restriction (FR). The food restriction protocol lasted six weeks, being the SPA measured weekly by a gravimetric apparatus. At the end of the experiment, biochemical analyses were performed in serum and tissue samples with statistical significance set at 5%. RESULTS FR showed less SPA than CG, as occurred for body mass, water intake, adipose tissue and liver, heart and soleus glycogen, serum glucose, total protein, triglycerides and total cholesterol (P<0.05). CONCLUSION Data set demonstrates that low substrate stores signaled to decrease spontaneous physical activity to save energy.(AU)

Resting energy expenditure adaptation after short-term caloric restriction in morbidly obese women / Adaptação do gasto energético de repouso após restrição calórica de curto prazo em mulheres com obesidade mórbida

Objective:The objective of this study was to describe changes in the resting energy expenditure, substrate oxidation rate, and body composition in morbidly obese women subjected to short-term caloric restriction. Methods:This was a prospective study that included ten obese women with body mass index greater than 40 kg/m2 and aged between 20-50 years. The participants were hospitalized for eight days and received a controlled conventional low-calorie diet, 1200 kcal/day, for seven days. Body weight, body mass index, abdominal circumference, body composition, resting energy expenditure, and substrate oxidation rate were evaluated at the beginning and at the end of the study. Results:A significant reduction in body weight (p=0.005), body mass index (p=0.005), abdominal circumference (p=0.005), fat mass (p=0.005) and fat-free mass (p=0.008) was observed at the end of the study. There was an average reduction in resting energy expenditure of approximately 124 kcal/day (5%). Substrate oxidation rate did not show statistically significant changes. There was a positive correlation only between body weight reduction and fat-free mass reduction (r=0.753; p=0.012). Conclusion:There was an adaptive response of the resting energy expenditure with short-term energy restriction in morbidly obese women with a 5% reduction in resting energy expenditure and a positive correlation between weight loss and the fat-free mass, which indicates the influence of fat-free mass on the decrease in resting energy expenditure. Therefore, short-term caloric restriction in morbidly obese women led to a decrease in resting energy expenditure and fat-free mass, which suggests a rapid adaptation of energy expenditure.

Objetivo:Descrever as mudanças no gasto energético de repouso, na taxa de oxidação de substrato e na composição corporal em mulheres obesas mórbidas submetidas à restrição calórica de curto prazo. Métodos:Este foi um estudo prospectivo com dez mulheres obesas com índice de massa corporal maior que 40 kg/m2 e idade entre 20-50 anos. As participantes foram hospitalizadas por sete dias consecutivos e receberam uma dieta hipocalórica convencional controlada de 1200 kcal/dia. Peso corporal, índice de massa corporal, circunferência abdominal, composição corporal, gasto energético de repouso e taxa de oxidação de substratos foram avaliados no início e no final do estudo.Resultados:Reduções significativas no peso corporal (p=0,005), índice de massa corporal (p=0,005), circunferência abdominal (p=0,005), massa gorda (p=0,005) e massa livre de gordura (p=0,008) foram observadas no final do estudo. O gasto energético de repouso mostrou redução média de aproximadamente 124 kcal/dia (5%). A taxa de oxidação de substratos não apresentou mudanças estatisticamente significativas. Houve correlação importante apenas entre a redução do peso corporal e a redução da massa livre de gordura (r=0,753, p=0,012). Conclusão:Houve uma resposta adaptativa do gasto energético de repouso com restrição energética em curto prazo em mulheres obesas mórbidas, apresentando redução média de 5% do gasto energético de repouso e correlação entre a perda de peso e a massa livre de gordura, o que indica a influência da mesma na diminuição do gasto energético de repouso. Portanto, a restrição calórica de curto prazo em mulheres obesas mórbidas leva à diminuição no gasto energético de repouso e na massa livre de gordura, sugerindo uma rápida adaptação do gasto energético.

Energy restriction and impact on indirect calorimetry and oxidative stress in cardiac tissue in rat.

Caloric restriction, defined as a reduction in calorie intake below ad libitum, without malnutrition can have beneficial effects. In this study, we evaluated the impact of caloric restriction of 30 and 60% on calorimetric parameters and oxidative stress in cardiac tissue in rats. Rats were randomly divided into 3 groups (n = 8): G1 = control; G2 = rats exposed to dietary restriction of 30%; and G3 = rats exposed to dietary restriction of 60%. Energy restriction decreased final body weight, oxidation of carbohydrates and lipid, oxygen consumption (VO2), carbon dioxide production (VCO2), resting metabolic rate (RMR), but elevated respiratory quotient (RQ). G3 animals also displayed an imbalance in the oxidant/antioxidant system, as revealed by the decrease in the lipid hydroperoxide (LH) level and GSH-Px activity in heart tissue. In conclusion, dietary restriction decreased oxidative metabolism, as seen by the colorimetric profiles and controlled oxidative stress in cardiac tissue.

Long-term caloric restriction up-regulates PPAR gamma co-activator 1 alpha (PGC-1 ) expression in mice.

The peroxisome proliferator-activated receptor (PPAR) gamma co-activator 1 alpha (PGC-1 ), a signal-sensing transcriptional co-activator in association with many nuclear receptors regulates various genes that control energy balance in animals. In this study, the effect of long-term caloric restriction (CR) (alternate days of fasting for 3 months) on the expression of PGC-1 protein in various tissues was investigated in mice. Western blot analyses showed positive immunoreactive PGC-1 (~92 kDa) signal from various tissues. Heart, kidney and skeletal muscles expressed significant levels of PGC-1 , while a comparatively lower level was detected in the liver, small intestine and brain. The expression of PGC-1 was the highest and lowest in the heart and liver respectively. CR mice exhibited a significant increase in PGC-1a level in the heart (5.13-fold), kidney (3.57-fold), skeletal muscle (3.02-fold), liver (2.60-fold), small intestine (2.45-fold) and brain (2.05-fold), compared to normal (ad libitum) fed. The elevation in PGC-1 level, especially in highly oxidative tissues such as heart, kidney and skeletal muscle of CR mice might synergistically up-regulate genes that require PGC-1 co-activation. Taken together, the up-regulation of PGC-1 expression might potentially support optimal energy metabolism and biochemical adaptation, necessary for maintaining energy homeostasis during long-term CR.

Metabolismo mitocondrial y ultraestructura de músculo esquelético de ratón con restricción calórico proteica / Mitochondrial metabolism and ultrastructure of mice's skeletal muscle with caloric proteic restriction

Para estudiar el metabolismo mitocondrial en este trabajo se utilizó el método de permeabilización del tejido muscular mediante saponina, la cual destruye el sarcolema, manteniendo las mitocondrias "in situ". Para crear un modelo de patología mitocondrial se produjo restricción calórico-proteica (RCP) en ratones adultos con un 50 por ciento de la dieta de los ratones alimentados "ad libitum" durante un período de 15 días. Se efectuaron estudios del consumo de oxígeno, relación ADP/O, así como la actividad enzimática de los Complejos I y II de la cadena respiratoria y la determinación de proteínas. Para evaluar el efecto de la saponina sobre el tejido muscular en presencia y ausencia de restricción calórica-proteica se observaron muestras del mismo al microscopio electrónico de transmisión. Los resultados revelaron en los animales una pérdida de peso, disminución en el consumo de oxígeno y de la relación ADP/O en presencia de glutamato y de succinato, por otra parte se obtuvo una disminución evidente de la actividad del Complejo I, sin modificación del Complejo II. Las observaciones obtenidas con el microscopio electrónico demuestran que la RCP en ratas tiene efecto directo sobre el aparato contráctil de las fibras musculares, produciendo desorganización de las estructuras sarcoméricas y reducción importante de los miofilamentos. La saponina, por otra parte afecta todo el sistema de citomembranas.

In this work, the method of permeabilization of muscular tissue with saponin was employed, which destroyed the sarcolemma but maintained the mitochondria "in situ". To create a model of mitochondrial pathology, a caloric-protein restriction (CPR) was produced in adult mice by reducing 50 percent the diet to fed animals for 15 days. Determinations of oxygen consumption, ADP/O ratio, total proteins, as well as enzymatic activities of respiratory chain Complexes I and II were performed. To evaluate the effect of saponin on muscular tissues under normal or CPR conditions, electron microscopy observations were done. Results of the study showed that the animals in CPR group had loss of weight, reduced total proteins, diminished oxygen consumption, lower ADP/O ratio in the presence of glutamate and succinate, and a notable decrement in the activity of Complex I but without modifications of that of Complex II. Electron microscopic observations demonstrates directs effects of CPR over the contractile apparatus of muscle fibers, such as, disorganization of sarcomeric structures and an important reduction of the myofilaments. On the other hand, saponin affected all cytomembranous systems.