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The incidence of obesity and overweight in the world has been increasing in recent years due to poor diet and lack of physical activity; people suffering obesity and overweight, related with malnutrition due to excess, often resort to calorie restriction diets that are usually not very effective. In this context, intermittent fasting (IF) has become popular due to the possibilities for weight loss that it offers. This diet consists of alternating periods of fasting with unrestricted eating; however, its effectiveness and consequences are unknown to most users. This narrative review analyzes whether intermittent fasting contributes to the improvement of body and metabolic composition. The purpose of the review was to examine the available data on the contribution of intermittent fasting to the improvement of body and metabolic composition, in order to provide information and to define the parameters that condition safe achievement of its benefits. IF dieting triggers adaptive cell responses that cause a decrease in lipid oxidative stress markers in individuals with obesity and prediabetes. Metabolic alterations have been found to go hand in hand with the alteration of circadian rhythms; if IF contributes to this effect, it may assist in treating and preventing obesity and associated diseases. However, there are also disadvantages, such as the loss of lean muscle mass by wasting, and increased hypoglycemia(AU)
La incidencia de obesidad y sobrepeso en el mundo ha ido en aumento en los últimos años debido a la mala alimentación y la falta de actividad física; Las personas que padecen obesidad y sobrepeso, relacionadas con la desnutrición por exceso, suelen recurrir a dietas de restricción calórica que suelen ser poco efectivas. En este contexto, el ayuno intermitente (AI) se ha popularizado debido a las posibilidades de pérdida de peso que ofrece. Esta dieta consiste en alternar períodos de ayuno con alimentación sin restricciones; sin embargo, su eficacia y consecuencias son desconocidas para la mayoría de los usuarios. Esta revisión narrativa analiza si el ayuno intermitente contribuye a la mejora de la composición corporal y metabólica. El objetivo de la revisión fue examinar los datos disponibles sobre la contribución del ayuno intermitente a la mejora de la composición corporal y metabólica, con el fin de aportar información y definir los parámetros que condicionan la consecución segura de sus beneficios. Se ha encontrado que las alteraciones metabólicas van de la mano con la alteración de los ritmos circadianos; si AI contribuye a este efecto, puede ayudar a tratar y prevenir la obesidad y las enfermedades asociadas. Sin embargo, también existen desventajas, como la pérdida de masa muscular magra por atrofia y el aumento de la hipoglucemia(AU)
Subject(s)
Humans , Male , Female , Weight Loss , Overweight , Intermittent Fasting/adverse effects , Obesity , Prediabetic State , Body Composition , Deficiency Diseases , Delivery of Health Care , HypoglycemiaABSTRACT
Intermittent fasting (IF) has gained increasing scientific and general attention. Most studied forms of IF include alternate-day fasting, modified alternate-day fasting, and time-restricted eating (TRE). Several cardiometabolic effects of IF have been described in animal models and, to a lesser extent, in humans. This review analyzes the impact of IF on weight loss, glucose metabolism, blood pressure, and lipid profile in humans. A literature search was conducted in the Pubmed/Medline, Scopus, and Google Scholar databases. Controlled observational or interventional studies in humans, published between January 2000 and June 2021, were included. Studies comparing IF versus religious fasting were not included. Most studies indicate that the different types of IF have significant benefits on body composition, inducing weight loss and reducing fat mass. Changes in cardiometabolic parameters show more divergent results. In general, a decrease in fasting glucose and insulin levels is observed, together with an improved lipid profile associated with cardiovascular risk. High heterogeneity in study designs was observed, particularly in studies with TRE, small sample sizes, and short-term interventions. Current evidence shows that IF confers a range of cardiometabolic benefits in humans. Weight loss, improvement of glucose homeostasis and lipid profile, are observed in the three types of IF protocols evaluated.
Subject(s)
Humans , Animals , Cardiovascular Diseases/prevention & control , Intermittent Fasting , Weight Loss , Fasting/physiology , Glucose/metabolism , LipidsABSTRACT
Dr. Jason Fung presents a novel, comprehensive model of obesity that delivers unexpected insights into healthy eating in this highly accessible and challenging book. Dr. Fung is a nephrologist (kidney doctor) who launched the Intensive Dietary Management program in Toronto. Dr. Jason Fung is regarded as a member of the foremost experts on intermittent fasting, a subject I knew very little about before going through his book. His intermittent fasting approach is his trademark prescription for obesity and type 2 diabetes individuals. Dr. Fung discusses utilizing intermittent fasting to end the cycle of insulin resistance and achieve a healthy weight
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El ayuno intermitente se ha popularizado como una estrategia alternativa para el control de peso y disminución de algunos parámetros bioquímicos. El propósito de esta revisión sistemática fue evaluar la efectividad del ayuno intermitente en dos protocolos: ayuno en días intermitentes (ADA) y ayuno restringido en el tiempo (ART), sobre el perfil lipídico, composición corporal y presión arterial en adultos. Método: Revisión sistemática basada en ensayos controlados aleatorios consultados en las bases de datos: Web of Science, Scopus, Cochrane Library, Clinical Trials, Proquest y PubMed. Se estudió a adultos mayores de 18 años con cualquier estado nutricional. La intervención correspondió a ayuno intermitente de al menos 16 horas. Se evaluaron riesgos de sesgos según la colaboración de Cochrane. Resultados: Se analizaron seis ensayos clínicos, encontrándose que el protocolo ADA, presente en cuatro de ellos, generó cambios en las variables: triglicéridos, c-HDL, c-LDL, colesterol total, peso, masa magra, masa grasa y presión arterial sistólica, mientras que el protocolo ART, presente en los dos restantes, provocó cambios en las variables: peso, masa grasa, masa magra, triglicéridos, colesterol total, c-LDL, c-HDL y glicemia. Conclusión: La evidencia disponible con ensayos clínicos nos permite sugerir que los protocolos ADA y ART pueden ser una dieta alternativa para adultos. Sin embargo, el ajuste calórico y una adecuada educación sobre estilos de vida saludable muestran resultados similares. Sin perjuicio a esto, el AI puede ser una alternativa para aquellos a quienes les es difícil seguir un patrón dietético con restricción calórica diaria.
Intermittent fasting has become popular as an alternative strategy for weight control and the reduction of some biochemical parameters. The purpose of this systematic review (SR) was to evaluate the effectiveness of intermittent fasting in two protocols: intermittent days fasting (ADA) and time-restricted fasting (ART), on lipid profile, body composition and blood pressure among adults. Methods: SR based on randomized controlled trials consulted in the following databases: Web of Science, Scopus, Library Cochrane, Clinical Trials, Proquest and PubMed. Adults over 18 years of age with any nutritional status were studied. The intervention corresponded to intermittent fasting of at least 16 hours. Risk of bias were assessed according to the Cochrane collaboration. Results: Six clinical trials were analyzed, finding that the ADA protocol, present in four of them, generated changes in the variables: triglycerides, c-HDL, c-LDL, total cholesterol, weight, lean mass, fat mass and systolic blood pressure, while the ART protocol, present in the remaining two, caused changes in the variables: weight, fat mass, lean mass, triglycerides, total cholesterol, c-LDL, c-HDL and glycemia. Conclusion: The available evidence with clinical trials allows us to suggest that the ADA and ART protocols can be an alternative diet for adults. However, caloric adjustment and adequate education on healthy lifestyles show similar results. Notwithstanding this, intermittent fasting may be an alternative for those who find it difficult to follow a dietary pattern with daily caloric restriction.
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Objective:To investigate the protective effect of intermittent fasting on radiation-induced cognitive impairment and the possible underlying mechanism.Methods:A total of 36 male 7-week old c57BL/6J mice were divided into Sham-irradiation and ad libitum (Sham-AL) group, irradiation and ad libitum (IR-AL) group, and irradiation add intermittent fasting (IR-IF) group according to the random number table method, with 12 mice in each group. The cognitive function of mice was assessed by novel object recognition task. The expressions of autophagy gene 5 (ATG5), microtubulesas sociated protein light chain II (LC3II), voltage dependent anion channel protein 1 (VDAC1), interleukin-1β (IL-1β), synaptophysin (SYP), synapsin I (SYN-1), and postsynaptic density 95 (PSD95) were tested by Western blot. The location of VDAC1 in mice hippocampus was detected by immunofluorescence.Results:The discrimination index (-22.45 ± 16.76) of IR-AL group was significantly ( t=3.032, P<0.05) lower than that of Sham-AL group (30.02 ± 9.05). Compared to Sham-AL group, IR-AL group had a decreased expressions of autophagy-related proteins (ATG5 and LC3II), mitochondrial marker (VDAC1), inflammatory factors (IL-1β) as well as synapse-associated proteins SYP, SYN-1 and PSD95 ( t=2.49, 2.19, 2.40, 3.47, 2.87, 2.25, 2.17, 2.31, P<0.05). Compared to IR-AL group, IR-IF group had an increased discrimination index (21.22 ± 5.62) and the increased expressions of ATG5, LC3II, VDAC1, IL-1β, SYP, SYN-1, and PSD95 ( t=2.70, 2.88, 2.71, 3.18, 3.18, 3.11, 3.30, 3.35, 2.53, P<0.05). The immunofluorescence assay revealed that VDAC1 was co-expressed with the markers of astrocytes (GFAP) and microglia (IBA-1), but not with neurons (NEUN). Conclusions:Intermittent fasting could greatly improve the cognitive function of irradiated mice possibly by upregulating VDAC1 expression, induce autophagy, and inhibit the release of inflammatory factors and protecting the synapticplasticity in the hippocampus.
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Increasingly researches suggested that intermittent fasting (IF) can be part of a healthy lifestyle, which can improve risk factors associated with obesity and diabetes. Based on LC-MS metabolomics technology, this study preliminarily discussed the effect of IF on the metabolism of mice under normal physiological conditions by detecting the fecal metabolites. All experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Shanghai University of Traditional Chinese Medicine. The mice were subjected to intermittent fasting for 10 weeks by fasting for 24 hours on alternate days, and their feces at 5 and 10 weeks were collected. The results show that the weight, food and water intake was not significant altered in mice with IF, but fasting blood glucose level was decreased. We found that fecal metabolites change was present at 5-week, being more prominent in 10-week. Relative to the control mice, we detected 17 and 108 metabolites in two time points, respectively. These metabolites were mainly enriched in the pathways of linoleic acid metabolism and bile acid biosynthesis. We further found that 10 metabolites may be a close correlation with IF, which had the same change trend at two time points. In conclusion, the present study provides a new approach to study the metabolism mechanism in IF treatment of related diseases.
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Resumen Introducción: la obesidad representa una importante problemática a nivel mundial, esto genera la necesidad de encontrar nuevas estrategias terapéuticas que contribuyan a tratar dicha enfermedad. En los últimos años, ha surgido el ayuno intermitente (AI) como una posible alternativa dietoterápica en el descenso de peso y en la mejora de variables cardiometabólicas, aunque la evidencia científica es controvertida. Objetivos: evaluar la evidencia científica disponible respecto a la efectividad del ayuno intermitente en el descenso de peso y en la mejora de las variables cardiometabólicas en comparación con la restricción energética continua. Materiales y Método: se ha llevado a cabo una búsqueda sistemática de ensayos clínicos aleatorizados (ECA) en las bases de datos PUBMED y Cochrane Library. Se incluyeron 11 ECA, que compararan AI con restricción energética continua (REC) con un rango de duración de 4 a 48 semanas, en mujeres y hombres con un índice de masa corporal (IMC) ≥25 kg/m2 y que hayan evaluado descenso de peso y variables cardiometabólicas. Resultados: el AI presentó una mediana de descenso de peso de 5,5 kg (RIQ: 4,7;6,86 kg), mientras que para la REC fue de 4,8 kg (RIQ: 3,8;6,6 kg). El IMC, la masa grasa, la masa libre de grasa y circunferencia de cintura, se redujeron de manera significativa tanto para la intervención como para el comparador. Asimismo, las variables cardiometabólicas presentaron mejoras respecto a los valores iniciales, sin embargo, evidenciaron resultados heterogéneos. Conclusiones: tanto el AI como la REC resultaron ser efectivas para la mejora de las variables estudiadas. La intervención no demostró ser mejor que el comparador.
Abstract Introduction: obesity represents a major problem worldwide, and this generates the need to find new therapeutic tools that contribute to the treatment of this disease. In recent years, intermittent fasting (IF) has emerged as a possible dietary alternative in weight loss and improvement of cardiometabolic variables, although the scientific evidence is controversial. Objectives: to evaluate the available scientific evidence regarding the effectiveness of intermittent fasting in weight loss and in the improvement of cardiometabolic variables in comparison with continuous energy restriction. Materials and Method: a systematic search of PUBMED and Cochrane Library databases for randomized clinical trials (RCTs) has been conducted. Eleven RCTs were included, comparing IF with continuous energy restriction (CER) with a duration range of 4 to 48 weeks, in women and men with a body mass index (BMI) ≥25 kg/m2 and who assessed weight loss and cardio metabolic variables. Results: the IF presented a median weight loss of 5.5 kg (IQR:4.7; 6.86 kg), while for CER it was 4.8 kg (IQR: 3.8; 6.6 kg). BMI, fat mass, fat-free mass, and waist circumference were significantly reduced for both the intervention and the comparator. Likewise, the cardiometabolic variables presented improvements with respect to the initial values, however, they showed heterogeneous results. Conclusions: both IF and CER proved to be effective in improving the variables studied; the intervention did not prove to be better than the comparator.
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ABSTRACT Intermittent fasting (IF) is an increasingly popular method of weight loss, as an alternative to daily caloric restriction (DCR). Several forms of IF exist, such as alternate-day fasting or time-restricted feeding regimens. Some of its proponents claim several health benefits unrelated to caloric restriction or weight loss, which rely mainly on animal models. Although several studies published in the last few years confirm that IF can be a useful and safe therapeutical option for obesity and related disorders, no superiority to conventional caloric restriction diets have emerged. There are still several questions left answered. In this Review, we discuss some of the claims, unveiling myths, facts, and presumptions about several models of IF. The focus of this article is obesity, but there is a brief discussion of the potential benefits of IF on overall human health.
Subject(s)
Humans , Animals , Fasting , Obesity , Weight Loss , Caloric RestrictionABSTRACT
Dietary intervention is essential as a primary prevention measure for cardiovascular diseases. Nurses master scientific dietary guidance methods, which can help reduce the risk of cardiovascular diseases in high-risk groups and reduce the medical burden of cardiovascular diseases. This paper reviews the classification of intermittent fasting, its impact on cardiovascular risk factors, its possible mechanisms for preventing cardiovascular diseases, its safety and compliance, and suggestions on domestic cardiovascular research. In order to provide references for future research in China.
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Background: Chronic low grade inflammation is anessential pathological feature of various Noncommunicable Diseases (NCDs). Carbohydrate rich food animportant modifiable risk factor contributing to NCDscan be restricted by Ketogenic Diet (KD) or IntermittentFasting (IF). So the present study was taken up toevaluate the role of the above interventions ininflammation induced by Complete Freund's Adjuvant(CFA) in male Wistar rats. Aim and Objectives: Toevaluate the role of KD and IF in a model ofinflammation induced by CFA in rats. Material andMethods: Animals were divided into 4 equal groups of10 rats each. Groups were based on diet given. Group I -Control fed with standard diet; Group II - KD; Group III- IF and Group IV- Disease free group on standard diet.CFA injection into the hind paw 4 weeks after startingthe diet was made in all groups except in group IV afterwhich serum cytokines and oxidative stress markerswere measured on day 21. Results: KD and IF groupsshowed significantly lower inflammation in terms ofpaw edema volume and serum cytokines namely TNFα and IL-1β as compared to the control group. The KDand IF groups also showed lower oxidative stress interms of lower serum Thiobarbituric Acid ReactiveSpecies (TBARS) and less depletion of antioxidantenzymes namely superoxide dismutase and catalase ascompared to control group. Conclusion: The presentstudy proves that it is possible to lower inflammationand hence prevent NCDs by IF and KD. Since theimpact of both interventions on inflammation is similar,IF may be preferable to KD because, carbohydrate ispresent in a sizeable amount in most foodstuffs that weconsume and daily restriction of carbohydrate in theform of KD may not be a feasible option. Hence, IFalone may be a better option than daily carbohydraterestriction in the form of KD.
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El ayuno intermitente es una estrategia nutricional de creciente interés para el control del peso y mejora de la salud metabólica. El objetivo del presente estudio fue evaluar el efecto de un protocolo de ayuno intermitente sobre la composición corporal, perfil lipídico y los biomarcadores de riesgo cardiovascular en estudiantes universitarios. En este estudio experimental participaron 30 sujetos varones y fueron divididos aleatoriamente en dos grupos, 15 sujetos constituían el grupo experimental (GE) (edad: 20,83±0,98 años) y 15 el grupo control (GC) (edad: 23,71±5,55 años). El GE realizó un protocolo de ayuno 16/8, dieciséis horas de ayuno y ocho horas de ingesta calórica sin limitaciones, dos días consecutivos a la semana durante cinco semanas. Se evaluó la composición corporal, la ingesta calórica, el perfil lipídico y los biomarcadores del riesgo cardiovascular al inicio, mitad y final del protocolo. Se observaron descensos significativos en el GE en pliegues cutáneos, perímetro cintura, porcentaje de grasa, perfil lipídico y biomarcadores del riesgo cardiovascular en comparación con GC (p<0,05). Se encontraron incrementos significativos en la ingesta de colesterol y ácidos grasos poliinsaturados en el GE al final del estudio (p<0,05). Se observaron descensos en el colesterol total, triglicéridos, lipoproteínas de baja densidad y biomarcadores del riesgo cardiovascular a lo largo del protocolo en el GE (p<0,05). Un protocolo de ayuno intermitente 16/8, dos días consecutivos por semana, durante cinco semanas, parece efectivo para mejorar parámetros de composición corporal y perfil lipídico, así como para mejorar los biomarcadores relacionados con el riesgo cardiovascular(AU)
Intermittent fasting is a nutritional strategy of high interest in weight control and improvement of metabolic health. The objective of this study was to evaluate the effect of an intermittent fasting protocol on body composition, lipid profile and biomarkers of cardiovascular risk in university students. In this experimental study thirty male subjects participated and were randomly divided into two groups; fifteen subjects constituted the experimental group (GE) (age: 20.83 ± 0.98 years) and fifteen the control group (GC) (age: 23.71 ± 5.55 years). The GE performed a fasting protocol 16/8, sixteen hours of fasting and eight hours of caloric intake without limitations, two consecutive days per week for five weeks. Body composition, calorie intake, lipid profile and biomarkers of cardiovascular risk were evaluated at the beginning, middle and at the end of the protocol. Significant decreases were found in GE in skinfolds, waist perimeter, % fat, lipid profile and biomarkers of cardiovascular risk as compared to GC (p <0.05). There were significant increases in the intake of cholesterol and polyunsaturated fatty acids in the GE at the end of the study (p <0.05). There were decreases in total cholesterol, triglycerides, low-density lipoproteins, and biomarkers of cardiovascular risk throughout the study in GE (p<0.05). An intermittent fasting protocol 16/8, two consecutive days per week, for five weeks, seems effective to improve parameters of body composition and lipid profile, as well as to improving biomarkers related to cardiovascular risk(AU)
Subject(s)
Humans , Male , Adult , Fasting/adverse effects , Feeding Behavior , Lipids/analysis , Body Composition , Nutritional Status , Food CompositionABSTRACT
Intermittent fasting diet (IF) as a restrictive regimen prevents neural degeneration and stimulates overexpression of various neurotropic factors in the hippocampus of animal models. This study evaluates the potential effect of the IF in the prevention of learning and memory dysfunction and improving the alterations in the number and volume of neurons in an ethidium bromide (EB) induced mouse model of demyelination.Mice were randomly assigned into N group (Normal Diet and normal saline injection), F group (IF and normal saline injection), EBN group (Normal Diet and EB injection), EBF group (IF and EB injection). The hidden platform test was carried out based on path length, escape latency and swim speeds of mice. Stereological studies were determined by the Cavalieri and the Optical Dissector technique. Maintenance of mice on the IF results in significantly decreased the body weight and biochemical parameters, increased total number of neurons and volume of the hippocampus, and improved learning and memory parameters of adult male mice. However, IF in EBF group did not show as excellently as F group. The EBF group displayed significantly spatial memory improvement than that in EBN group. There were no statistically significant differences between EBF and EBN groups in stereological and learning parameters, though the EBF group displayed faster escape latencies, and swam faster and shorter path lengths than the EBN group in these parameters. Therefore as a conclusion, The IF fairly improved some adverse effects of EB in experimental demyelination models.
La dieta de ayuno intermitente (AI) como régimen restrictivo, previene la degeneración neural y la estimación de la presencia de diversos factores neurotrópicos en el hipocampo de modelos animales. Este estudio evalúa el efecto potencial de la AI en la prevención del aprendizaje y la disfunción de la memoria y mejora las alteraciones en el número y el volumen de las neuronas en un modelo de desmielinización, en ratón, inducido con bromuro de etidio (BE). Los ratones se asignaron al azar en el grupo N (dieta normal e inyección salina normal), Grupo A (AI e inyección salina normal), Grupo BEN (dieta normal e inyección BE), Grupo EBF (inyección AI y BE). La prueba de la plataforma oculta se llevó a cabo en función de la longitud del trayecto, la latencia de escape y la velocidad de nado de los ratones. Los estudios estereológicos fueron determinados por la técnica de Cavalieri y la técnica del disector óptico. En el grupo AI disminuyeron significativamente el peso corporal de los ratones, los parámetros bioquímicos, el número total de neuronas y el volumen del hipocampo, y los parámetros de aprendizaje y la memoria de los ratones machos adultos. Sin embargo, el grupo AI en BEF no se mostró tan bien como el grupo A. El grupo EBF mostró una mejora en la memoria espacial significativamente mayor que la del grupo BEN. No hubo diferencias estadísticamente significativas entre los grupos A, BE y BEN en los parámetros estereológicos y de aprendizaje, aunque el grupo EBF mostró latencias de escape más rápidas, y nado en las rutas más rápidas y más cortas que el grupo BEN en estos parámetros. Por lo tanto, como conclusión, el grupo AI mejoró bastante algunos efectos adversos de la BE en los modelos de desmielinización experimental.
Subject(s)
Animals , Male , Mice , Fasting , Demyelinating Diseases/chemically induced , Hippocampus/pathology , Body Weight , Disease Models, Animal , Ethidium/toxicity , Learning , Mice, Inbred BALB CABSTRACT
Vascular dementia is the most common neuropsychiatric syndrome and is characterized by synaptic dysfunction, neuroinflammation, and cognitive dysfunction. Vascular dementia is associated with various environmental, genetic, and lifestyle risk factors. Recent research has focused on the association between vascular dementia and dietary patterns, suggesting that dietary regulation leads to better control of energy metabolism, improvements in brain insulin resistance, and the suppression of neuroinflammation. Intermittent fasting is a calorie-restriction method known to be more effective in promoting fat loss and regulating the impairment of glucose metabolism as compared with other dietary restriction regimens. Herein, the authors review the effects of intermittent fasting with regard to vascular dementia based on recent evidence and propose that intermittent fasting could be a therapeutic approach for ameliorating vascular dementia pathology and preventing its onset.
Subject(s)
Brain , Cognition , Dementia, Vascular , Energy Metabolism , Fasting , Glucose , Insulin Resistance , Life Style , Metabolism , Methods , Pathology , Risk FactorsABSTRACT
Objective@#To compare the weight loss and metabolic profile between a continuous energy-restricted diet and intermittent fasting diet in order to present an optimal nutritional weight reduction method for obese people in China.@*Methods@#Sixty overweight or obese adults were selected and divided into two groups as the continuous energy-restricted diet group and the intermittent fasting diet group. Height, weight, waist circumference, body mass index(BMI), body fat, change of visceral fatarea, fasting glucose(FPG), triglyceride(TG), total cholesterol(TC), high density cholesterol(HDL), low density cholesterol(LDL), glutamic pyruvicaminotransferase(AST), signglutamic pyruvic transaminase(ALT), gamma-glutamyltranspeptidase(GGT), alkalinephosphatase (ALP), fasting insulin level(FINS) and HOMA-IR were assessed at baseline and 8 weeks after weight loss methods carried.@*Results@#Both continuous energy-restricted diet and intermittent fasting diet resulted improvement on body shape indexes and a significant decrease in weight, waist circumference, BMI, body fat, visceral fat area and skeletal muscle(P<0.01)at 8 weeks. Both groups experienced improvements in biochemical outcomes and metabolic indicators at 8 weeks. A significant reduction in TC, AST, ALT, GGT, ALP, FINS and HOMA-IR(P<0.01 or P<0.05)were observed in continuous energy-restricted diet group. And a significant decline in TC, LDL, HDL, AST, ALT, GGT, ALP, FINS and HOMA-IR were observed in intermittent fasting diet group(P<0.01 or P<0.05). HDL was found significantly reduced in intermittent fasting diet group as compared with continuous energy-restricted diet group(P<0.01) at 8 weeks, however, there were no difference in weight loss, waist circumference, BMI, body fat, visceral fat area and other metabolic indicators at 8 weeks(P>0.05).@*Conclusion@#Both intermittent fasting diet and continuous energy-restricted diet have a similar effect on weight loss and metabolic indexes like blood glucose, HOMA-IR and blood lipid, but intermittent fasting diet can more significantly decrease HDL level.
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@#Obesity is now recognised as a chronic disease which needs chronic treatment to treat or prevent obesity related complications. This article discusses the biology of weight regulation as a basis to understanding obesity as a disease, and to appreciate the complex and multifactorial nature of the obesity problem. Finally, the article highlights the dietary approaches as part of the multi-pronged approach to treating obesity and gives a brief update on intermittent fasting.
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Objective To compare the weight loss and metabolic profile between a continuous energyrestricted diet and intermittent fasting diet in order to present an optimal nutritional weight reduction method for obese people in China. Methods Sixty overweight or obese adults were selected and divided into two groups as the continuous energy-restricted diet group and the intermittent fasting diet group. Height, weight, waist circumference, body mass index (BMI), body fat, change of visceral fatarea, fasting glucose (FPG), triglyceride (TG), total cholesterol ( TC), high density cholesterol ( HDL), low density cholesterol (LDL), glutamic pyruvicaminotransferase ( AST), signglutamic pyruvic transaminase ( ALT), gammaglutamyltranspeptidase (GGT), alkalinephosphatase (ALP), fasting insulin level (FINS) and HOMA-IR were assessed at baseline and 8 weeks after weight loss methods carried. Results Both continuous energy-restricted diet and intermittent fasting diet resulted improvement on body shape indexes and a significant decrease in weight, waist circumference, BMI, body fat, visceral fat area and skeletal muscle (P<0. 01) at 8 weeks. Both groups experienced improvements in biochemical outcomes and metabolic indicators at 8 weeks. A significant reduction in TC, AST, ALT, GGT, ALP, FINS and HOMA-IR (P<0. 01 or P<0. 05) were observed in continuous energy-restricted diet group. And a significant decline in TC, LDL, HDL, AST, ALT, GGT, ALP, FINS and HOMA-IR were observed in intermittent fasting diet group (P <0. 01 or P < 0. 05). HDL was found significantly reduced in intermittent fasting diet group as compared with continuous energy-restricted diet group (P<0. 01) at 8 weeks, however, there were no difference in weight loss, waist circumference, BMI, body fat, visceral fat area and other metabolic indicators at 8 weeks (P>0. 05). Conclusion Both intermittent fasting diet and continuous energy-restricted diet have a similar effect on weight loss and metabolic indexes like blood glucose, HOMA-IR and blood lipid, but intermittent fasting diet can more significantly decrease HDL level.
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Objective To establish a stable and reliable mouse model as an alternative to the traditional model of impaired glucose tolerance induced by calorie restriction and its effect on glucose homeostasis.Methods Forty 16-week-old SPF C57BL/6J mice (half male and half female) were randomly divided into four groups by sex and the way of feeding.The mice in the ad libitum (AL) group had free access to basic diet, while the mice in the intermittent fasting (IF) group had normal diet and fasting on alternate days, with free access to water on the fasting days.The changes of body weight and blood glucose concentration in each group were monitored, and intraperitoneal glucose tolerance test and insulin tolerance test in mice were performed before and after the 12-week IF treatment.Results At 12 weeks after IF treatment, the body weight and blood glucose concentration of mice did not show significant difference.After i.p.injection of glucose, the blood glucose concentration of IF mice was less increased than the AL group, and after the insulin injection, the blood glucose concentration was more decreased.Compared to the AL group, the areas under the curve of tolerance test in the IF group were significantly decreased (P < 0.05).Conclusions After IF treatment, the mice show an enhanced sensitivity to insulin and improved glucose tolerance.This establishment method of mouse model of intermittent fasting is easy and simple, therefore, can be used as an effective alternative to traditional calorie restriction model of impaired glucose tolerance.
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Objective To observe the changes of body weight,fat mass and skeletal muscle mass of rats after 4 weeks of intermittent fasting,and explore relationship with autophagy in skeletal muscle,so as to provide theoretical basis for intermittent fasting.Method Twenty male Sprague Dawley rats were randomly divided into a control group (Con) and an intermittent fasting group (IF),each of 10.The rats of IF group were forbidden to eat food every Wednesday and Friday,and the body weight of both groups was recorded weekly.After 4 weeks,Dual-Energy X-Ray Absorption (DEXA) was used to analyze the body fat mass,then the bilateral soleus was separated to record the wet weight and measure the cross-sectional area of the soleus fibers by testing laminin with immunofluorescence confocal laser scanning microscope.The form of autophagic vacuole of soleus was observed using a transmission electron microscopy.The expression of autophagy-related protein LC3,p62 and regulating protein AMPK,pAMPK and ULK1 were measured using Western blotting.Result After 4 weeks of intermittent fasting,the weight and fat mass of IF were significantly lower than those of Con (P＜0.01),but there were no significant differences between them in wet weight and cross-sectional area of soleus (P＞0.05).The expressions of AMPK,p-AMPK,ULK1 in IF were significantly higher than those in Con (P＜0.01).Compared with Con,the expression of LC3-Ⅱ/LC3-Ⅰ of IF increased significantly,while the expression of p62 decreased significantly (P＜0.01).Conclusion Four weeks of intermittent fasting decreases the fat mass significantly,and control the weight efficiently.Intermittent fasting can maintain the skeletal muscle mass by promoting moderate autophagy through the AMPK-ULK1 pathway.It should be a potential lose weight method for further research.
ABSTRACT
As dietas intermitentes (IF) compreendem ciclos alternados de 24 horas de jejum e alimentação. Como os efeitos de IF sobre o balanço redox não são bem conhecidos, esse trabalho teve por objetivo avaliar os efeitos desta dieta sobre o estado redox de diferentes tecidos de ratos. Após um mês de tratamento, os fígados dos ratos em IF apresentaram um aumento de capacidade respiratória mitocondrial juntamente com níveis elevados de proteínas carboniladas. Verificou-se ainda um aumento em danos oxidativos no cérebro destes animais. IF promoveu significativa proteção contra danos oxidativos no coração, enquanto que não houve alterações no estado redox do músculo esquelético. Os efeitos metabólicos de IF também foram investigados com o intuito de compreender os mecanismos envolvidos com o menor peso e a hiperfagia promovidos por esta intervenção. Observou-se que o menor peso dos ratos submetidos à IF é consequência de um aumento em taxas metabólicas em dias de alimentação somado à oxidação lipídica aumentada durante o jejum. A hiperfagia, por sua vez, é consequencia de elevação nos níveis de neurotransmissores orexigênicos hipotalâmicos, mesmo quando estes animais estão alimentados. Os níveis do neutransmissor TRH também foram modulados por esta dieta, o que pode estar relacionado com as alterações de taxas metabólicas observadas no modelo. Concluímos, portanto, que as dietas intermitentes promovem modificações funcionais no hipotálamo que estão associadas com diferenças no peso corpóreo e no apetite. Além disso, IF afeta o balanço redox de forma tecido específica, levando a um desbalanço oxidativo no fígado e no cérebro e à proteção contra danos oxidativos no coração
Intermittent fasting (IF) is a dietary intervention that comprises 24 hour cycles alternating ad libitum feeding and fasting. We address here the effects of IF on redox state in different tissues, which are still poorly understood. After one month on the diet, IF rats livers presented increased mitochondrial respiratory capacity along with increased levels of protein carbonyls. Surprisingly, IF animals also presented an increase in oxidative damage in the brain. Conversely, IF promoted a substantial protection against oxidative damage in the heart. No difference in redox homeostasis was observed in the skeletal muscle. We also assessed metabolic effects of IF to uncover the mechanisms involved in the lower body mass and loss of feeding control in IF rats. As measured calorimetrically, IF animals presented high metabolic rates during feeding days and increased lipid oxidation on fasting days, which explains the lower body weight. IF-induced overeating was a consequence of increased expression of hypothalamic orexigenic neurotransmitters, even on feeding days. THR levels also were changed, in parallel with the feeding-dependent alterations on metabolic rates. Overall, we find that intermittent fasting promotes functional hypothalamic alterations associated with differences in body weight and appetite. In addition, IF affects redox balance in a tissue-specific manner, leading to redox imbalance in the liver and brain, as well as protection against oxidative damage in the heart