Effects of Periodic Fasting on Fatty Liver Index-A Prospective Observational Study

Spermidine is essential for fasting-mediated autophagy and longevity

Caloric restriction and intermittent fasting prolong the lifespan and healthspan of model organisms and improve human health. The natural polyamine spermidine has been similarly linked to autophagy enhancement, geroprotection and reduced incidence of cardiovascular and neurodegenerative diseases across species borders. Here, we asked whether the cellular and physiological consequences of caloric restriction and fasting depend on polyamine metabolism. We report that spermidine levels increased upon distinct regimens of fasting or caloric restriction in yeast, flies, mice and human volunteers. Genetic or pharmacological blockade of endogenous spermidine synthesis reduced fasting-induced autophagy in yeast, nematodes and human cells. Furthermore, perturbing the polyamine pathway in vivo abrogated the lifespan- and healthspan-extending effects, as well as the cardioprotective and anti-arthritic consequences of fasting. Mechanistically, spermidine mediated these effects via autophagy induction and hypusination of the translation regulator eIF5A. In summary, the polyamine-hypusination axis emerges as a phylogenetically conserved metabolic control hub for fasting-mediated autophagy enhancement and longevity.

The Relationship between Pathogenesis and Possible Treatments for the MASLD-Cirrhosis Spectrum

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a term that entails a broad spectrum of conditions that vary in severity. Its development is influenced by multiple factors such as environment, microbiome, comorbidities, and genetic factors. MASLD is closely related to metabolic syndrome as it is caused by an alteration in the metabolism of fatty acids due to the accumulation of lipids because of an imbalance between its absorption and elimination in the liver. Its progression to fibrosis is due to a constant flow of fatty acids through the mitochondria and the inability of the liver to slow down this metabolic load, which generates oxidative stress and lipid peroxidation, triggering cell death. The development and progression of MASLD are closely related to unhealthy lifestyle habits, and nutritional epigenetic and genetic mechanisms have also been implicated. Currently, lifestyle modification is the first-line treatment for MASLD and nonalcoholic steatohepatitis; weight loss of ≥10% produces resolution of steatohepatitis and fibrosis regression. In many patients, body weight reduction cannot be achieved; therefore, pharmacological treatment should be offered in particular populations.

Efficacy and safety of prolonged water fasting: a narrative review of human trials

The goal of this narrative review is to summarize the effects of prolonged fasting on various metabolic health measures, including body weight, blood pressure, plasma lipids, and glycemic control. Prolonged fasting is characterized by consciously eating little to no food or caloric beverages for several days to weeks. Results reveal that prolonged fasting for 5-20 days produces potent increases in circulating ketones, and mild to moderate weight loss of 2-10%. Approximately two-thirds of the weight lost is lean mass, and one-third is fat mass. The excessive lean mass loss suggests that prolonged fasting may increase the breakdown of muscle proteins, which is a concern. Systolic and diastolic blood pressure consistently decreased with prolonged fasting. However, the impact of these protocols on plasma lipids is less clear. While some trials demonstrate decreases in LDL cholesterol and triglycerides, others show no benefit. With regard to glycemic control, reductions in fasting glucose, fasting insulin, insulin resistance, and glycated hemoglobin (HbA1c) were noted in adults with normoglycemia. In contrast, these glucoregulatory factors remained unchanged in patients with type 1 or type 2 diabetes. The effects of refeeding were also examined in a few trials. It was shown that 3-4 months after the fast was completed, all metabolic benefits were no longer observed, even when weight loss was maintained. With regard to adverse events, metabolic acidosis, headaches, insomnia, and hunger were observed in some studies. In summary, prolonged fasting appears to be a moderately safe diet therapy that can produce clinically significant weight loss (>5%) over a few days or weeks. However, the ability of these protocols to produce sustained improvements in metabolic markers warrants further investigation.

Various types of fasting diet and possible benefits in nonalcoholic fatty liver: Mechanism of actions and literature update

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver injury, affecting around one-fourth of the general population across the world. Several important pathophysiological mechanisms underlying NAFLD include oxidative stress, inflammation, liver fibrosis, and apoptosis. Currently, therapeutic approaches are not ideal for managing NAFLD, thus new approaches and treatments are still needed. Over the last two decades, various fasting protocols have been explored to reduce body weight and improve metabolic disorders. In this review, we provide updated literature that supports fasting regimens for subjects with NAFLD and describes underlying mechanisms of action. We suggest that fasting regimens may modulate NAFLD via several mechanisms, including changes in gut microbiota, hepatic arginase, hepatic autophagy, inflammatory responses, liver functional enzymes and hepatic steatosis, fibroblast growth factors signaling, white adipose tissue browning, adipokines, circadian rhythms, lipid profiles, and body composition.

Improvements during long-term fasting in patients with long COVID - a case series and literature review

Background

Post-acute sequelae of a severe acute respiratory syndrome coronavirus 2 infection, also known as long COVID, comprises a variety of symptoms that impair the quality of life. This represents a growing public health burden, with millions of individuals worldwide affected.

Case description

We present a case series of 14 COVID-19 patients with post-acute symptoms who underwent medically supervised long-term fasting (6 to 16 days) according to the peer-reviewed Buchinger Wilhelmi protocol. The EQ-5D-5L questionnaire and visual scales were used to evaluate the intensity of the symptoms, retrospectively during the acute phase, and prospectively before and after long-term fasting. Blood tests were also performed before and after fasting. Thirteen patients reported that fasting caused an enhancement in their perceived overall health. Only one patient had no improvement. Both frequent (fatigue, breathlessness, muscle and joint pains) and less frequent (cognitive impairment, smell and taste disorders) sequelae ameliorated. Body weight and other risk factors for cardiometabolic diseases like blood pressure, blood glucose, total cholesterol, low-density-lipoprotein cholesterol, and triglycerides were reduced. No severe side effects occurred.

Discussion

This case series reports beneficial changes in self-perceived symptoms in patients with long COVID after long-term fasting. This highlights the potential of long-term fasting as an effective intervention for managing and treating long COVID.

The Role of the Fatty Liver Index (FLI) in the Management of Non-Alcoholic Fatty Liver Disease: A Systematic Review

Currently, non-alcoholic fatty liver disease is the most common liver disease worldwide, with a prevalence of 32%. It is much more common among men (40%) and among patients with metabolic comorbidities such as obesity, diabetes and dyslipidemia. Being an asymptomatic disease, the diagnosis is often established on the basis of imaging methods, with an important role given to abdominal ultrasonography, computed tomography and magnetic resonance imaging. In order to facilitate diagnosis, experts have introduced a series of blood biomarkers. Two biomarker panels are currently validated for the diagnosis of non-alcoholic fatty liver disease: the fatty liver index, and the hepatic steatosis index. The fatty liver index has been in use in medical practice for over 17 years and has demonstrated its accuracy in various studies that compared it with other diagnostic methods, highlighted its role in screening patients with cardiovascular risk and validated the effects of different diets and drugs that are proposed for the treatment of the disease. In the management of non-alcoholic fatty liver disease, the fatty liver index is an important algorithm in the diagnosis and prognosis of patients with metabolic risk. Taking into account the diversity of drugs to be approved in the treatment of non-alcoholic fatty liver disease, the fatty liver index will become an effective tool in monitoring the effects of these therapies.

Intermittent fasting-the future treatment in NASH patients?

NASH is one of the leading causes of chronic liver disease with the potential of evolving towards end-stage liver disease and HCC, even in the absence of cirrhosis. Apart from becoming an increasingly prevalent indication for liver transplantation in cirrhotic and HCC patients, its burden on the healthcare system is also exerted by the increased number of noncirrhotic NASH patients. Intermittent fasting has recently gained more interest in the scientific community as a possible treatment approach for different components of metabolic syndrome. Basic science and clinical studies have shown that apart from inducing body weight loss, improving cardiometabolic parameters, namely blood pressure, cholesterol, and triglyceride levels; insulin and glucose metabolism; intermittent fasting can reduce inflammatory markers, endoplasmic reticulum stress, oxidative stress, autophagy, and endothelial dysfunction, as well as modulate gut microbiota. This review aims to further explore the main NASH pathogenetic metabolic drivers on which intermittent fasting can act upon and improve the prognosis of the disease, and summarize the current clinical evidence.

[Fasting - a potent modern therapy]

Therapeutic fasting has found its way into modern medicine in the last decade through a multitude of experimental work and animal studies as well as increasing clinical research. It is a procedure with a tradition dating back thousands of years and thus comes with a variety of different practices. What they all have in common, is the reduction of daily food intake for a limited period of time. This has a variety of effects on metabolism, cells and organ systems, which can make it a potent tool in medical practice.

Effects of Prolonged Fasting during Inpatient Multimodal Treatment on Pain and Functional Parameters in Knee and Hip Osteoarthritis: A Prospective Exploratory Observational Study

Preliminary clinical data suggest that pain reduction through fasting may be effective for different diagnoses. This uncontrolled observational clinical study examined the effects of prolonged modified fasting on pain and functional parameters in hip and knee osteoarthritis. Patients admitted to the inpatient department of Internal Medicine and Nature-based Therapies of the Immanuel Hospital Berlin between February 2018 and December 2020 answered questionnaires at the beginning and end of inpatient treatment, as well as at 3, 6, and 12 months after discharge. Additionally, selected blood and anthropometric parameters, as well as subjective pain ratings, were routinely assessed during the inpatient stay. Fasting was the only common intervention for all patients, being performed as part of a multimodal integrative treatment program, with a daily caloric intake of <600 kcal for 7.7 ± 1.7 days. N = 125 consecutive patients were included. The results revealed an amelioration of overall symptomatology (WOMAC Index score: -14.8 ± 13.31; p < 0.001; d = 0.78) and pain alleviation (NRS Pain: -2.7 ± 1.98, p < 0.001, d = 1.48). Pain medication was reduced, stopped, or replaced by herbal remedies in 36% of patients. Improvements were also observed in secondary outcome parameters, including increased quality of life (WHO-5: +4.5 ± 4.94, p < 0.001, d = 0.94), reduced anxiety (HADS-A: -2.1 ± 2.91, p < 0001, d = 0.55) and depression (HADS-D: -2.3 ± 3.01, p < 0.001, d = 0.65), and decreases in body weight (-3.6 kg ± 1.65, p < 0.001, d = 0.21) and blood pressure (systolic: -6.2 ± 15.93, p < 0.001, d = 0.43; diastolic: -3.7 ± 10.55, p < 0.001, d = 0.43). The results suggest that patients with osteoarthritis of the lower extremities may benefit from prolonged fasting as part of a multimodal integrative treatment to improve quality of life, pain, and disease-specific functional parameters. Confirmatory randomized controlled trials are warranted to further investigate these hypotheses.

Different Dietary Approaches, Non-Alcoholic Fatty Liver Disease and Cardiovascular Disease: A Literature Review

Non-alcoholic fatty liver disease (NAFLD) is the first cause of chronic liver disease and is also associated with other harmful entities such as obesity, metabolic syndrome, dyslipidemia, and diabetes. NAFLD is a significant public health concern worldwide, impacting individuals of all ages, and its prevalence is projected to increase in the near future due to its connection with obesity. Intrinsic (genetics) and external (lifestyle) factors may also modulate NAFLD, and, in turn, may partly explain the observed relationship between NAFLD and cardiovascular disease (CVD). Although many drugs are been tested to treat NAFLD, to date, no drug has indication to specifically treat this disorder. Thus, the current management of NAFLD relies on lifestyle modifications and specifically on weight loss, physical activity, and the intake of a healthy diet. In the present narrative review, we will discuss the effects of certain dietary patterns on NAFLD incidence and progression.

Dietary patterns and cardiometabolic health: Clinical evidence and mechanism

For centuries, the search for nutritional interventions to underpin cardiovascular treatment and prevention guidelines has contributed to the rapid development of the field of dietary patterns and cardiometabolic disease (CMD). Numerous studies have demonstrated that healthy dietary patterns with emphasis on food-based recommendations are the gold standard for extending lifespan and reducing the risks of CMD and mortality. Healthy dietary patterns include various permutations of energy restriction, macronutrients, and food intake patterns such as calorie restriction, intermittent fasting, Mediterranean diet, plant-based diets, etc. Early implementation of healthy dietary patterns in patients with CMD is encouraged, but an understanding of the mechanisms by which these patterns trigger cardiometabolic benefits remains incomplete. Hence, this review examined several dietary patterns that may improve cardiometabolic health, including restrictive dietary patterns, regional dietary patterns, and diets based on controlled macronutrients and food groups, summarizing cutting-edge evidence and potential mechanisms for CMD prevention and treatment. Particularly, considering individual differences in responses to dietary composition and nutritional changes in organ tissue diversity, we highlighted the critical role of individual gut microbiota in the crosstalk between diet and CMD and recommend a more precise and dynamic nutritional strategy for CMD by developing dietary patterns based on individual gut microbiota profiles.

Fasten – ein potentes Therapeutikum der Moderne

Fasten als Therapie hat im letzten Jahrzehnt durch eine Fülle an Grundlagenstudien und experimentellen Arbeiten sowie zunehmende klinische Forschung seinen Einzug in die moderne Medizin gehalten. Es ist ein Verfahren mit jahrtausendealter Tradition und dadurch verschiedenartigen Durchführungsmöglichkeiten. Gemeinsam ist ihnen die Reduktion der täglichen Nahrungsaufnahme für begrenzte Zeit. Diese hat vielfältige Wirkungen auf Stoffwechsel, Zellen und Organsysteme, die es zu einem potenten Mittel im ärztlichen Handeln machen können.

Fasting intervention and its clinical effects on the human host and microbiome

Experimental trials in organisms ranging from yeast to humans have shown that various forms of reducing food intake (caloric restriction) appear to increase both overall and healthy lifespan, delaying the onset of disease and slowing the progression of biomarkers of aging. The gut microbiota is considered one of the key environmental factors strongly contributing to the regulation of host health. Perturbations in the composition and activity of the gut microbiome are thought to be involved in the emergence of multiple diseases. Indeed, many studies investigating gut microbiota have been performed and have shown strong associations between specific microorganisms and metabolic diseases including overweight, obesity, and type 2 diabetes mellitus as well as specific gastrointestinal disorders, neurodegenerative diseases, and even cancer. Dietary interventions known to reduce inflammation and improve metabolic health are potentiated by prior fasting. Inversely, birth weight differential host oxidative phosphorylation response to fasting implies epigenetic control of some of its effector pathways. There is substantial evidence for the efficacy of fasting in improving insulin signaling and blood glucose control, and in reducing inflammation, conditions for which, additionally, the gut microbiota has been identified as a site of both risk and protective factors. Accordingly, human gut microbiota, both in symbiont and pathobiont roles, have been proposed to impact and mediate some health benefits of fasting and could potentially affect many of these diseases. While results from small-N studies diverge, fasting consistently enriches widely recognized anti-inflammatory gut commensals such as Faecalibacterium and other short-chain fatty acid producers, which likely mediates some of its health effects through immune system and barrier function impact.

Long-term fasting: Multi-system adaptations in humans (GENESIS) study–A single-arm interventional trial

Fasting provokes fundamental changes in the activation of metabolic and signaling pathways leading to longer and healthier lifespans in animal models. Although the involvement of different metabolites in fueling human fasting metabolism is well known, the contribution of tissues and organs to their supply remains partly unclear. Also, changes in organ volume and composition remain relatively unexplored. Thus, processes involved in remodeling tissues during fasting and food reintroduction need to be better understood. Therefore, this study will apply state-of-the-art techniques to investigate the effects of long-term fasting (LF) and food reintroduction in humans by a multi-systemic approach focusing on changes in body composition, organ and tissue volume, lipid transport and storage, sources of protein utilization, blood metabolites, and gut microbiome profiles in a single cohort. This is a prospective, single-arm, monocentric trial. One hundred subjects will be recruited and undergo 9 ± 3 day-long fasting periods (250 kcal/day). We will assess changes in the composition of organs, bones and blood lipid profiles before and after fasting, as well as high-density lipoprotein (HDL) transport and storage, untargeted metabolomics of peripheral blood mononuclear cells (PBMCs), protein persulfidation and shotgun metagenomics of the gut microbiome. The first 32 subjects, fasting for 12 days, will be examined in more detail by magnetic resonance imaging (MRI) and spectroscopy to provide quantitative information on changes in organ volume and function, followed by an additional follow-up examination after 1 and 4 months. The study protocol was approved by the ethics board of the State Medical Chamber of Baden-Württemberg on 26.07.2021 and registered at ClinicalTrials.gov (NCT05031598). The results will be disseminated through peer-reviewed publications, international conferences and social media.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT05031598].

The effects of fasting diets on nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. There is no confirmed treatment for NAFLD as yet. Recently, fasting regimens and their relationship to NAFLD have drawn a great deal of attention in the literature. We review the current evidence that supports fasting diets as an adjunctive therapeutic strategy for patients with NAFLD and address potential action mechanisms. We reason that the fasting diets might be a promising approach for modulating hepatic steatosis, fibroblast growth factors 19 and 21 signaling, lipophagy, and the metabolic profile.

Is Fasting Good When One Is at Risk of Liver Cancer?

Hepatocellular carcinoma (HCC), one of the leading causes of cancer-related deaths worldwide, is a multistep process that usually develops in the background of cirrhosis, but also in a non-cirrhotic state in patients with non-alcoholic fatty liver disease (NAFLD) or viral hepatis. Emerging evidence suggests that intermittent fasting can reduce the risk of cancer development and could improve response and tolerance to treatment through the metabolic and hormonal adaptations induced by the low energy availability that finally impairs cancer cells’ adaptability, survival and growth. The current review will outline the beneficial effects of fasting in NAFLD/NASH patients and the possible mechanisms that can prevent HCC development, including circadian clock re-synchronization, with a special focus on the possibility of applying this dietary intervention to cirrhotic patients.

A Six-Week Follow-Up Study on the Sustained Effects of Prolonged Water-Only Fasting and Refeeding on Markers of Cardiometabolic Risk

(1) Background: Chronic inflammation and insulin resistance are associated with cardiometabolic diseases, such as cardiovascular disease, type 2 diabetes mellitus, and non-alcoholic fatty liver disease. Therapeutic water-only fasting and whole-plant-food refeeding was previously shown to improve markers of cardiometabolic risk and may be an effective preventative treatment but sustained outcomes are unknown. We conducted a single-arm, open-label, observational study with a six-week post-treatment follow-up visit to assess the effects of water-only fasting and refeeding on markers of cardiometabolic risk. (2) Methods: Patients who had voluntarily elected and were approved to complete a water-only fast were recruited from a single-center residential medical facility. The primary endpoint was to describe changes to Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) scores between the end-of-refeed visit and the six-week follow-up visit. Additionally, we report on changes in anthropometric measures, blood lipids, high-sensitivity C-reactive protein (hsCRP), and fatty liver index (FLI). Observations were made at baseline, end-of-fast (EOF), end-of-refeed (EOR), and six-week follow-up (FU). (3) Results: The study enrolled 40 overweight/obese non-diabetic participants, of which 33 completed the full study protocol. Median fasting, refeeding, and follow-up lengths were 14, 6, and 45 days, respectively. At the FU visit, body weight (BW), body mass index (BMI), abdominal circumference (AC), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein (LDL), hsCRP, and FLI were significantly decreased from baseline. Triglycerides (TG) and HOMA-IR scores, which had increased at EOR, returned to baseline values at the FU visit. (4) Conclusion: Water-only fasting and whole-plant-food refeeding demonstrate potential for long-term improvements in markers of cardiovascular risk including BW, BMI, AC, SBP, DBP, blood lipids, FLI, and hsCRP.

Improving the accuracy of fatty liver index to reflect liver fat content with predictive regression modelling

Background

The fatty liver index (FLI) is frequently used as a non-invasive clinical marker for research, prognostic and diagnostic purposes. It is also used to stratify individuals with hepatic steatosis such as non-alcoholic fatty liver disease (NAFLD), and to detect the presence of type 2 diabetes or cardiovascular disease. The FLI is calculated using a combination of anthropometric and blood biochemical variables; however, it reportedly excludes 8.5-16.7% of individuals with NAFLD. Moreover, the FLI cannot quantitatively predict liver fat, which might otherwise render an improved diagnosis and assessment of fatty liver, particularly in longitudinal studies. We propose FLI+ using predictive regression modelling, an improved index reflecting liver fat content that integrates 12 routinely-measured variables, including the original FLI.

Methods and findings

We evaluated FLI+ on a dataset from the UK Biobank containing 28,796 individual estimates of proton density fat fraction derived from magnetic resonance imaging across normal to severe levels and interpolated to align with the original FLI range. The results obtained for FLI+ outperform the original FLI by delivering a lower mean absolute error by approximately 47%, a lower standard deviation by approximately 20%, and an increased adjusted R² statistic by approximately 49%, reflecting a more accurate representation of liver fat content.

Conclusions

Our proposed model predicting FLI+ has the potential to improve diagnosis and provide a more accurate stratification than FLI between absent, mild, moderate and severe levels of hepatic steatosis.

Effect of 5:2 Fasting Diet on Liver Fat Content in Patients with Type 2 Diabetic with Nonalcoholic Fatty Liver Disease

Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) is rapidly growing in China, especially in patients with type 2 diabetes mellitus (T2DM). Weight loss strategies have been shown to treat NAFLD effectively. We conducted a 24-week, prospective, randomized study in T2DM patients with NAFLD to evaluate the effects of a 5:2 fasting diet on liver fat content. Methods: Sixty-one T2DM patients with NAFLD were enrolled and randomly divided into a 5:2 fasting diet intervention group (5:2 diet group, n = 31) and 1.8 mg/day liraglutide intervention group (Lira group, n = 30). The study was performed for 24 weeks. Data of the body weight, waist circumference, plasma lipids and glucose profile, fasting plasma insulin, and liver function parameters were collected. Controlled attenuation parameter (CAP) was measured to assess the liver fat content. Superoxide dismutase (SOD) and malondialdehyde (MDA) were measured to evaluate oxidative stress status. Results: At 24 weeks after intervention, compared with those at baseline, CAP was significantly decreased in both the 5:2 diet group and Lira group, which was 7.4% and 5.5%, respectively. Body weight, plasma lipids and glucose profile, and liver function parameters improved significantly, while homeostasis model assessment-β (HOMA-β) was significantly increased in both groups (all P < 0.05). Stepwise linear regression showed that increased HOMA-β and SOD, as well as reduced body mass index (BMI), were the independent predictors of CAP decrease in the Lira group (P = 0.000, 0.000, 0.015). In contrast, reduced BMI and MDA were the independent influencing factors of CAP decrease in the 5:2 diet group (P = 0.011, 0.043). The common side effects in the 5:2 diet group were hunger (60%), weakness (10%), and constipation (0.3%). Conclusions: A 5:2 fasting diet achieved comparable effects with liraglutide on liver fat content in patients with T2DM with NAFLD by reducing BMI and oxidative stress. Both treatment strategies were safe and effective for glucose control.

Intermittent Fasting: Potential Utility in the Treatment of Chronic Pain across the Clinical Spectrum

Dietary behavior can have a consequential and wide-ranging influence on human health. Intermittent fasting, which involves intermittent restriction in energy intake, has been shown to have beneficial cellular, physiological, and system-wide effects in animal and human studies. Despite the potential utility in preventing, slowing, and reversing disease processes, the clinical application of intermittent fasting remains limited. The health benefits associated with the simple implementation of a 12 to 16 h fast suggest a promising role in the treatment of chronic pain. A literature review was completed to characterize the physiologic benefits of intermittent fasting and to relate the evidence to the mechanisms underlying chronic pain. Research on different fasting regimens is outlined and an overview of research demonstrating the benefits of intermittent fasting across diverse health conditions is provided. Data on the physiologic effects of intermittent fasting are summarized. The physiology of different pain states is reviewed and the possible implications for intermittent fasting in the treatment of chronic pain through non-invasive management, prehabilitation, and rehabilitation following injury and invasive procedures are presented. Evidence indicates the potential utility of intermittent fasting in the comprehensive management of chronic pain and warrants further investigation.

Dietary patterns in non-alcoholic fatty liver disease (NAFLD): Stay on the straight and narrow path!

Non-alcoholic fatty liver disease (NAFLD) is the most frequent hepatic disease globally. NAFLD patients are at an increased risk of both liver and cardiovascular morbidity and mortality, as well as all-cause death. NAFLD prevalence is rapidly increasing worldwide and, thus, there is an urgent need for health policies to tackle its development and complications. Currently, since there is no drug therapy officially indicated for this disease, lifestyle interventions remain the first-line therapeutic option. In the present narrative review, we discuss the effects of certain dietary patterns on NAFLD incidence and progression. The Mediterranean diet is regarded as the diet of choice for the prevention/treatment of NAFLD and its complications, based on the available evidence. Other plant-based dietary patterns (poor in saturated fat, refined carbohydrates, red and processed meats) are also beneficial [i.e., Dietary Approaches to Stop Hypertension (DASH) and vegetarian/vegan diets], whereas more data are needed to establish the role of ketogenic, intermittent fasting and paleo diets in NAFLD. Nevertheless, there is no "one-size-fits-all" dietary intervention for NAFLD management. Clinicians should discuss with their patients and define the diet that each individual prefers and is able to implement in his/her daily life.

Metabolic Strategies in Healthcare: A New Era

Modern healthcare systems are founded on a disease-centric paradigm, which has conferred many notable successes against infectious disorders in the past. However, today's leading causes of death are dominated by non-infectious "lifestyle" disorders, broadly represented by the metabolic syndrome, atherosclerosis, cancer, and neurodegeneration. Our disease-centric paradigm regards these disorders as distinct disease processes, caused and driven by disease targets that must be suppressed or eliminated to clear the disease. By contrast, a health-centric paradigm recognizes the lifestyle disorders as a series of hormonal and metabolic responses to a singular, lifestyle-induced disease of mitochondria dysfunction, a disease target that must be restored to improve health, which may be defined as optimized mitochondria function. Seen from a health-centric perspective, most drugs target a response rather than the disease, whereas metabolic strategies, such as fasting and carbohydrate-restricted diets, aim to restore mitochondria function, mitigating the impetus that underlies and drives the lifestyle disorders. Substantial human evidence indicates either strategy can effectively mitigate the metabolic syndrome. Preliminary evidence also indicates potential benefits in atherosclerosis, cancer, and neurodegeneration. Given the existing evidence, integrating metabolic strategies into modern healthcare systems should be identified as a global health priority.

Is there an 'ideal' diet for patients with NAFLD?

Nonalcoholic fatty liver disease (NAFLD) is a growing epidemic that encompasses three distinct clinical phenotypes: uncomplicated fatty liver, nonalcoholic steatohepatitis (NASH) and NASH-related cirrhosis with its complications, including hepatocellular carcinoma. To date, no pharmacological treatments have been approved and lifestyle modifications including reduced caloric intake targeting a 7%-10% weight loss from baseline assessment represent the standard approach. Mediterranean diet has been recommended as the best dietary pattern since it is easy to follow and, independently of caloric intake its nutritional components have beneficial metabolic effects that not only improve steatosis but also risk factors for cardiovascular events, the leading cause of morbidity/mortality in individuals with NAFLD. Other dietary patterns such as ketogenic diet and Dietary Approach to Stop Hypertension (DASH) diet can be used in patients with NAFLD. Recently, intermittent fasting diets have gained popularity among healthy individuals and have been proposed as a safe and effective treatment for the metabolic syndrome in experimental and in a few human studies. In this narrative review, we aim to summarize the evidence for the available dietary approaches for patients with NAFLD.

Intermittent Fasting: Potential Bridge of Obesity and Diabetes to Health?

Obesity has been an escalating worldwide health problem for decades, and it is likely a risk factor of prediabetes and diabetes. Correlated with obesity, the number of diabetic patients is also remarkable. A modest weight loss (5–10%) is critical to alleviate the risk of any other metabolic disease. Reduced energy intake has been an essential factor for weight loss reduction. As a new behavior intervention to lose weight, intermittent fasting (IF) attracts considerable attention and has become a popular strategy among young people. IF is a diet pattern that cycles between periods of fasting and eating on a regular schedule, involving various types, mainly Intermittent Energy Restriction and Time-Restricted Fasting. Accumulating evidence shows that short-term IF has a greatly positive effect in animal studies and contributes favorable benefits in human trials as well. Nevertheless, as an emerging, diverse, and relatively premature behavior intervention, there are still limited studies considering patients with obesity and type 2 diabetes mellitus. It is also a controversial intervention for the treatment of metabolic disease and cancer. The risks and challenges appear consequently. Additionally, whether intermittent fasting can be applied to long-term clinical treatment, and whether it has side effects during the long-term period or not, demands more large-scale and long-term experiments.

Intermittent Fasting as a Treatment for Nonalcoholic Fatty Liver Disease: What Is the Evidence?

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Alternate-day fasting alleviates high fat diet induced non-alcoholic fatty liver disease through controlling PPARα/Fgf21 signaling

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that ultimately leads to cirrhosis and hepatocellular carcinoma. Intermittent fasting has been proposed as a nonpharmacological dietary approach against metabolic diseases, including NAFLD. In this study, we aimed to investigate the effect of alternate day fasting (ADF) on high-fat diet (HFD)-induced NAFLD in C57BL/6 mice.

METHODS

A mouse model of fatty liver disease was established by feeding the mice a HFD for 16 weeks. The mice were administered by body weight, lipid accumulation and inflammation. PPARα, FGF21, serum triglycerides (TG), total cholesterol (TC), transaminase and lipogenesis were assessed.

RESULTS

The results showed that long-term ADF can attenuate fatty liver disease by reducing hepatic inflammation and lipid accumulation in a mouse model. Meanwhile, fasting elevated the expression of serum and hepatic fibroblast growth Factor 21 (Fgf21), a circulating hormone produced predominantly in the liver, and could effectively prevent and ameliorate the pathogenesis of NAFLD. Serum starvation also enhanced Fgf21 expression and reduced free fatty acid (FFA)-induced lipid storage in hepatocytes. Moreover, refeeding inhibited the increase in Fgf21 expression induced by fasting. This fasted-to-refed transition is closely related to the expression of Fgf21. Further in vitro and in vivo studies showed that fasting-sensitive PPARα is indispensable for the expression of Fgf21 and its protective effect on NAFLD.

CONCLUSION

These findings indicated that long-term ADF protects mouse livers against HFD induced fatty liver disease through controlling PPARα/Fgf21 signaling. In conclusion, ADF can emerge as a non-pharmacological dietary approach against fatty liver disease.

Clinical Value and Role of miR-129-5p in Non-Alcoholic Fatty Liver Disease

This study was to evaluate the expression of miR-129-5p in non-alcoholic fatty liver (NAFLD) patients and its clinical value and explore its regulatory effect on insulin resistance (IR). A total of 117 NAFLD patients and 110 healthy controls were included. The levels of miR-129-5p were detected by qRT-PCR. To assess the diagnostic value of miR-129-5p for NAFLD, the receiver operating characteristic curve (ROC) was established. C57Bl/6 mice were supplied with high-fat diet to establish NAFLD model. Intraperitoneal insulin tolerance test (IPITT) was carried out to evaluate the effect of miR-129-5p on IR in NAFLD animal model. miR-129-5p was highly expressed in the serum of NAFLD patients, and patients with HOMA-IR ≥2.5 had higher level of miR-129-5p than those with HOMA-IR <2.5. miR-129-5p had the ability to differentiate NAFLD patients from healthy individuals and might be associated with the development of IR. Serum miR-129-5p was positively correlated with the levels of HOMA-IR, BMI, total cholesterol (TC), and triglyceride (TG) in NAFLD patients. Downregulation of miR-129-5p regulates lipid metabolism and insulin sensitivity in NAFLD mice model. MiR-129-5p was upregulated in NAFLD patients and might be a potential diagnostic biomarker. The regulatory effect of miR-129-5p on NAFLD may function by regulating lipid accumulation and insulin sensitivity.

Aging Induces Hepatic Oxidative Stress and Nuclear Proteomic Remodeling in Liver from Wistar Rats

Aging is a continuous, universal, and irreversible process that determines progressive loss of adaptability. The liver is a critical organ that supports digestion, metabolism, immunity, detoxification, vitamin storage, and hormone signaling. Nevertheless, the relationship between aging and the development of liver diseases remains elusive. In fact, although prolonged fasting in adult rodents and humans delays the onset of the disease and increases longevity, whether prolonged fasting could exert adverse effects in old organisms remains incompletely understood. In this work, we aimed to characterize the oxidative stress and nuclear proteome in the liver of 3-month- and 24-month-old male Wistar rats upon 36 h of fasting and its adaptation in response to 30 min of refeeding. To this end, we analyzed the hepatic lipid peroxidation levels (TBARS) and the expression levels of genes associated with fat metabolism and oxidative stress during aging. In addition, to gain a better insight into the molecular and cellular processes that characterize the liver of old rats, the hepatic nuclear proteome was also evaluated by isobaric tag quantitation (iTRAQ) mass spectrometry-based proteomics. In old rats, aging combined with prolonged fasting had great impact on lipid peroxidation in the liver that was associated with a marked downregulation of antioxidant genes (Sod2, Fmo3, and Cyp2C11) compared to young rats. Besides, our proteomic study revealed that RNA splicing is the hepatic nuclear biological process markedly affected by aging and this modification persists upon refeeding. Our results suggest that aged-induced changes in the nuclear proteome could affect processes associated with the adaptative response to refeeding after prolonged fasting, such as those involved in the defense against oxidative stress.

The effects of Ramadan intermittent fasting on liver function in healthy adults: A systematic review, meta-analysis, and meta-regression

INTRODUCTION

Growing evidence is suggestive that intermittent fasting likely to improve liver function; however, still the evidences are controversial to draw a definitive conclusion. Therefore, we conducted a systematic review and meta-analysis to estimate the effect size for changes in liver function tests (LFT) in healthy people practicing Ramadan diurnal intermittent fasting (RDIF), and to examine the impact of different covariates using subgroup analysis and meta-regression.

METHODS

Scientific databases were searched from date of inception in 1950 to the end of July 2020. The liver function tests searched and analyzed were aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin (BLU), L-lactate dehydrogenase (LDH) and prothrombin time (PT).

RESULTS

Twenty studies (601 adult participants in total, aged 18-57 years) conducted in 10 countries between 1987 and 2020 were identified. RDIF-induced effect sizes for the LFT expressed as standardized mean difference (SMD) [95% confidence interval] were: AST (no. of studies K = 16, number of subjects N = 502, SMD = -0.257 [-0.381, -0.133], I² = 42%); ALT (K = 16, N = 502, SMD = -0.105 [-0.282, 0.07], I² = 71%); GGT (K = 2, N = 46, SMD = -0.533 [-0.842, -0.224], I² = 0%); ALP (K = 10, N = 312, SMD = -0.318 [-0.432, -0.204], I² = 0.0%); BLU (K = 10, N = 325, SMD = -0.264 [-0.520, -0.007], I² = 70.1%); LDH (K = 5, N = 145, SMD = -0.041 [-0.380, 0.298], I² = 72%); PT (K = 2, N = 74, SMD = -0.027 [-0.732, 0.678], I² = 87%).

CONCLUSION

RDIF induces significant but small (AST, ALP, BLU) to medium (GGT) positive changes on LFT, and may confer a transient, short-term protection against fatty liver disease in healthy subjects.

Association between toothbrushing and non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. Periodontitis, as chronic inflammatory destructive disease, is associated metabolic syndromes bidirectionally. Toothbrushing is an essential and important way to manage periodontitis through mechanical removal of biofilm at periodontal tissue. We aimed to assess the association between toothbrushing frequency and the prevalent NAFLD in nationally representative Korean adults. Among adults aged 19 years and older who participated in the Korea National Health and Nutrition Examination Survey in 2010, a total of 6,352 subjects were analyzed. NAFLD was defined as fatty liver index ≥60. Multiple logistic regression analysis was used to estimate multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs). An inverse association between toothbrushing frequency and NAFLD was found. The adjusted ORs (95% CIs) of NALFD was 0.56 (0.35-0.91) in the group who performed toothbrushing ≥ 3 per day compared to the group that performed toothbrushing ≤ 1 per day. For those with toothbrushing frequency ≤1 per day, the adjusted OR (95% CIs) of NAFLD was 2.26 (1.22-4.19) in smokers and 4.52 (1.97-10.38) in subjects with diabetes mellitus (DM), compared to those without the disease and with toothbrushing frequency ≥2 per day, respectively. Our results indicate that higher frequency of toothbrushing is inversely associated with NAFLD. As a modifiable oral habit, regular toothbrushing may be recommended to lower risk of NAFLD, especially in high risk groups such as smokers and diabetic patients.

Non-Alcoholic Fatty Liver Disease: Metabolic, Genetic, Epigenetic and Environmental Risk Factors

Non-alcoholic fatty liver disease (NAFLD) is one of the most frequent causes of chronic liver disease in the Western world, probably due to the growing prevalence of obesity, metabolic diseases, and exposure to some environmental agents. In certain patients, simple hepatic steatosis can progress to non-alcoholic steatohepatitis (NASH), which can sometimes lead to liver cirrhosis and its complications including hepatocellular carcinoma. Understanding the mechanisms that cause the progression of NAFLD to NASH is crucial to be able to control the advancement of the disease. The main hypothesis considers that it is due to multiple factors that act together on genetically predisposed subjects to suffer from NAFLD including insulin resistance, nutritional factors, gut microbiota, and genetic and epigenetic factors. In this article, we will discuss the epidemiology of NAFLD, and we overview several topics that influence the development of the disease from simple steatosis to liver cirrhosis and its possible complications.

Long-term fasting improves lipoprotein-associated atherogenic risk in humans

Purpose

Dyslipidemia is a major health concern associated with an increased risk of cardiovascular mortality. Long-term fasting (LF) has been shown to improve plasma lipid profile. We performed an in-depth investigation of lipoprotein composition.

Methods

This observational study included 40 volunteers (50% men, aged 32–65 years), who underwent a medically supervised fast of 14 days (250 kcal/day). Changes in lipid and lipoprotein levels, as well as in lipoprotein subclasses and particles, were measured by ultracentrifugation and nuclear magnetic resonance (NMR) at baseline, and after 7 and 14 fasting days.

Results

The largest changes were found after 14 fasting days. There were significant reductions in triglycerides (TG, − 0.35 ± 0.1 mmol/L), very low-density lipoprotein (VLDL)-TG (− 0.46 ± 0.08 mmol/L), VLDL-cholesterol (VLDL-C, − 0.16 ± 0.03 mmol/L) and low-density lipoprotein (LDL)-C (− 0.72 ± 0.14 mmol/L). Analysis of LDL subclasses showed a significant decrease in LDL1-C (− 0.16 ± 0.05 mmol/L), LDL2-C (− 0.30 ± 0.06 mmol/L) and LDL3-C (− 0.27 ± 0.05 mmol/L). NMR spectroscopy showed a significant reduction in large VLDL particles (− 5.18 ± 1.26 nmol/L), as well as large (− 244.13 ± 39.45 nmol/L) and small LDL particles (− 38.45 ± 44.04 nmol/L). A significant decrease in high-density lipoprotein (HDL)-C (− 0.16 ± 0.04 mmol/L) was observed. By contrast, the concentration in large HDL particles was significantly raised. Apolipoprotein A1 decreased significantly whereas apolipoprotein B, lipoprotein(a), fibrinogen and high-sensitivity C-reactive protein were unchanged.

Conclusion

Our results suggest that LF improves lipoprotein levels and lipoprotein subclasses and ameliorates the lipoprotein-associated atherogenic risk profile, suggesting a reduction in the cardiovascular risk linked to dyslipidemia.

Trial Registration

Study registration number: DRKS-ID: DRKS00010111 Date of registration: 03/06/2016 “retrospectively registered”.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02578-0.

Fasting-mediated metabolic and toxicity reprogramming impacts circulating microRNA levels in humans

It is well-established that long-term fasting improves metabolic health, enhances the total antioxidant capacity and increases well-being. MicroRNAs oversee energy homeostasis and metabolic processes and are widely used as circulating biomarkers to identify the metabolic state. This study investigated whether the expression levels of twenty-four metabolism-associated microRNAs are significantly altered following long-term fasting and if these changes correlate with biochemical and redox parameters in the plasma. Thirty-two participants with an average BMI of 28 kg/m² underwent a 10-day fasting period with a daily intake of 250 kcal under medical supervision. RT-qPCR on plasma small-RNA extracts revealed that the levels of seven microRNAs (miR-19b-3p, miR-22-3p, miR-122-5p, miR-126-3p, miR-142-3p, miR-143-3p, and miR-145-5p) were significantly altered following fasting. Importantly, the expression levels of these microRNAs have been consistently shown to change in the exact opposite direction in pathological states including obesity, diabetes, nonalcoholic steatohepatitis, and cardiovascular disease. Linear regression analyses revealed that among the microRNAs analyzed, anti-inflammatory miR-146-5p expression displayed most correlations with the levels of different biochemical and redox parameters. In silico analysis of fasting-associated microRNAs demonstrated that they target pathways that are highly enriched for intracellular signaling such mTOR, FoxO and autophagy, as well as extracellular matrix (ECM) interactions and cell-senescence. Overall, these data are consistent with a model in which long-term fasting engages homeostatic mechanisms associated with specific microRNAs to improve metabolic signaling regardless of health status.

Treatment of NAFLD with intermittent calorie restriction or low-carb high-fat diet - a randomised controlled trial

Background & Aims

The first-line treatment for non-alcoholic fatty liver disease (NAFLD) is weight reduction. Several diets have been proposed, with various effects specifically on liver steatosis. This trial compared the effects of intermittent calorie restriction (the 5:2 diet) and a low-carb high-fat diet (LCHF) on reduction of hepatic steatosis.

Methods

We conducted an open-label randomised controlled trial that included 74 patients with NAFLD randomised in a 1:1:1 ratio to 12 weeks' treatment with either a LCHF or 5:2 diet, or general lifestyle advice from a hepatologist (standard of care; SoC). The primary outcome was reduction of hepatic steatosis as measured by magnetic resonance spectroscopy. Secondary outcomes included transient elastography, insulin resistance, blood lipids, and anthropometrics.

Results

The LCHF and 5:2 diets were both superior to SoC treatment in reducing steatosis (absolute reduction: LCHF: -7.2% [95% CI = -9.3 to -5.1], 5:2: -6.1% [95% CI = -8.1 to -4.2], SoC: -3.6% [95% CI = -5.8 to -1.5]) and body weight (LCHF: -7.3 kg [95% CI = -9.6 to -5.0]; 5:2: -7.4 kg [95% CI = -8.7 to -6.0]; SoC: -2.5 kg [95% CI =-3.5 to -1.5]. There was no difference between 5:2 and LCHF (p = 0.41 for steatosis and 0.78 for weight). Liver stiffness improved in the 5:2 and SoC but not in the LCHF group. The 5:2 diet was associated with reduced LDL levels and was tolerated to a higher degree than LCHF.

Conclusions

The LCHF and 5:2 diets were more effective in reducing steatosis and body weight in patients with NAFLD than SoC, suggesting dietary advice can be tailored to meet individual preferences.

Lay summary

For a person with obesity who suffers from fatty liver, weight loss through diet can be an effective treatment to improve the condition of the liver. Many popular diets that are recommended for weight reduction, such as high-fat diets and diets based on intermittent fasting, have not had their effects on the liver directly evaluated. This study shows that both a low-carb high-fat and the 5:2 diet are effective in treating fatty liver caused by obesity.

Clinical Trials Registration

This study is registered at Clinicaltrials.gov (NCT03118310).

Association between nutrient patterns and fatty liver index: Baseline survey of the Japan Multi-Institutional Collaborative Cohort Study in Tokushima, Japan

BACKGROUNDS

The fatty liver index (FLI) is a good non-invasive approach for fatty liver disease diagnosis. The objective of this study was to examine the associations of nutrient patterns with nonalcoholic fatty liver disease (NAFLD) in a Japanese population.

METHODS

A total of 1,588 subjects (789 men and 799 women) aged 35 to 69 years were recruited in the baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture. Factor analysis was applied to energy-adjusted intake of 21 nutrients, and nutrient patterns were extracted. Multiple logistic regression analysis was used to analyze the relationships between nutrient patterns and the high FLI category (≥60).

RESULTS

Four nutrient patterns were extracted: Factor 1, vitamins, dietary fiber, iron and potassium pattern; Factor 2, fats and fat-soluble vitamins pattern; Factor 3, saturated fat, calcium, vitamin B₂ and low carbohydrate pattern; and Factor 4, sodium, protein and vitamin D pattern. After adjustment for sex, age, and other potential confounding variables, higher Factor 1 scores were significantly associated with lower odds ratios of NAFLD (P for trend <0.05). Analysis of each component of FLI showed that there were significant inverse associations between Factor 1 scores and high body mass index and large waist circumference.

CONCLUSION

The present findings suggest that a nutrient pattern rich in vitamins, fiber, iron, and potassium was associated with lower prevalence of NAFLD in a Japanese population. Obesity and abdominal obesity may be intermediate variables for the association between this nutrient pattern and NAFLD.

Therapy for Nonalcoholic Fatty Liver Disease: Current Options and Future Directions

PURPOSE

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease that is driven by the metabolic syndrome. NAFLD encompasses nonalcoholic fatty liver, >5% fat in the liver without inflammation of fibrosis, nonalcoholic steatohepatitis (NASH), fat plus varying degrees of inflammation and fibrosis, and cirrhosis of the liver from NASH. As facets of the metabolic syndrome, particularly diabetes and obesity, become more common worldwide, the incidence of new NAFLD is increasing.

METHODS

A qualitative systematic review was performed via searches of PubMed and ClinicalTrials.gov for therapeutic interventions for NAFLD.

FINDINGS

Current therapies rely on metabolic syndrome risk factor control and lifestyle changes to achieve weight loss. Because sustained weight loss is difficult for many patients, there is a critical unmet need for pharmacotherapy to treat NAFLD, especially the progressive form, NASH, to prevent cirrhosis of the liver. New therapies for NAFLD focus on the subset of patients with NASH and some degree of fibrosis. Novel mechanisms of action, including farnesoid X nuclear receptor agonism, C-C motif chemokine receptor 2 and receptor 5 antagonism, stearoyl-CoA desaturase-1, and thyroid hormone receptor β agonism, are currently under investigation as monotherapy. The products also hold potential for use in combination with and without insulin sensitizers and other established drugs in the future.

IMPLICATIONS

This review of NASH treatments details the interventions that are currently available as well as those in late-stage clinical trials that may represent the future of NASH therapy.

AGA Clinical Practice Update on Lifestyle Modification Using Diet and Exercise to Achieve Weight Loss in the Management of Nonalcoholic Fatty Liver Disease: Expert Review

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease, with global public health impact affecting more than 25% of the global population. NAFLD is associated with significant morbidity and mortality from cirrhosis, hepatocellular carcinoma, solid organ malignancies, diabetes mellitus, cardiovascular disease, and obstructive sleep apnea, resulting in significant health care resource use and decreased health-related quality of life. NAFLD cirrhosis is a leading indication for liver transplantation in the United States. Lifestyle modification to achieve weight loss remains a first-line intervention in patients with NAFLD. We summarize evidence-based interventions for lifestyle modification in the treatment of NAFLD and provided best practice advice statements to address key issues in clinical management.

Non-alcoholic Fatty Liver and Liver Fibrosis Predictive Analytics: Risk Prediction and Machine Learning Techniques for Improved Preventive Medicine

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with a prevalence of 20%-30% in the general population. NAFLD is associated with increased risk of cardiovascular disease and may progress to cirrhosis with time. The purpose of this study was to predict the risks associated with NAFLD and advanced fibrosis on the Fatty Liver Index (FLI) and the 'NAFLD fibrosis 4' calculator (FIB-4), to enable physicians to make more optimal preventive medical decisions. A prospective cohort of apparently healthy volunteers from the Tel Aviv Medical Center Inflammation Survey (TAMCIS), admitted for their routine annual health check-up. Data from the TAMCIS database were subjected to machine learning classification models to predict individual risk after extensive data preparation that included the computation of independent variables over several time points. After incorporating the time covariates and other key variables, this technique outperformed the predictive power of current popular methods (an improvement in AUC above 0.82). New powerful factors were identified during the predictive process. The findings can be used for risk stratification and in planning future preventive strategies based on lifestyle modifications and medical treatment to reduce the disease burden. Interventions to prevent chronic disease can substantially reduce medical complications and the costs of the disease. The findings highlight the value of predictive analytic tools in health care environments. NAFLD constitutes a growing burden on the health system; thus, identification of the factors related to its incidence can make a strong contribution to preventive medicine.

Nutritional Approaches for the Management of Nonalcoholic Fatty Liver Disease: An Evidence-Based Review

Nonalcoholic fatty liver disease (NAFLD) is on the rise worldwide representing a public health issue. Its coexistence with obesity and other metabolic alterations is highly frequent. Therefore, current therapy interventions for NAFLD are mainly focused on progressive weight loss through modulation of overall calorie intake with or without specific macronutrient adjustments. Furthermore, other relevant nutritional interventions are built on food selection and time-restricted eating. Since every strategy might bring different results, choosing the optimal diet therapy for a patient is a complicated task, because NAFLD is a multifactorial complex disease. Importantly, some factors need to be considered, such as nutrition-based evidence in terms of hepatic morphophysiological improvements as well as adherence of the patient to the meal plan and adaptability in their cultural context. Thus, the purpose of this review is to explore and compare the subtleties and nuances of the most relevant clinical practice guidelines and the nutritional approaches for the management of NAFLD with a special attention to tangible outcomes and long-term adherence.

Physiopathology of Lifestyle Interventions in Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a major health problem, and its prevalence has increased in recent years. Diet and exercise interventions are the first-line treatment options, with weight loss via a hypocaloric diet being the most important therapeutic target in NAFLD. However, most NAFLD patients are not able to achieve such weight loss. Therefore, the requisite is the investigation of other effective therapeutic approaches. This review summarizes research on understanding complex pathophysiology underlying dietary approaches and exercise interventions with the potential to prevent and treat NAFLD.

Understanding Dietary Intervention-Mediated Epigenetic Modifications in Metabolic Diseases

The global prevalence of metabolic disorders, such as obesity, diabetes and fatty liver disease, is dramatically increasing. Both genetic and environmental factors are well-known contributors to the development of these diseases and therefore, the study of epigenetics can provide additional mechanistic insight. Dietary interventions, including caloric restriction, intermittent fasting or time-restricted feeding, have shown promising improvements in patients' overall metabolic profiles (i.e., reduced body weight, improved glucose homeostasis), and an increasing number of studies have associated these beneficial effects with epigenetic alterations. In this article, we review epigenetic changes involved in both metabolic diseases and dietary interventions in primary metabolic tissues (i.e., adipose, liver, and pancreas) in hopes of elucidating potential biomarkers and therapeutic targets for disease prevention and treatment.

A Fad too Far? Dietary Strategies for the Prevention and Treatment of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a major health problem, and its prevalence has increased in recent years, concurrent with rising rates of obesity and other metabolic diseases. Currently, there are no FDA-approved pharmacological therapies for NAFLD, and lifestyle interventions, including weight loss and exercise, remain the cornerstones for treatment. Manipulating diet composition and eating patterns may be a sustainable approach to NAFLD treatment. Dietary strategies including Paleolithic, ketogenic, Mediterranean, high-protein, plant-based, low-carbohydrate, and intermittent fasting diets have become increasingly popular because of their purported benefits on metabolic disease. This review highlights what is currently known about these popular dietary approaches in the management of NAFLD in clinical populations with mechanistic insight from animal studies. It also identifies key knowledge gaps to better inform future preclinical and clinical studies aimed at the treatment of NAFLD.

Interplay between oxidative damage, the redox status, and metabolic biomarkers during long-term fasting

Obesity and its related metabolic disorders, as well as infectious diseases like covid-19, are important health risks nowadays. It was recently documented that long-term fasting improves metabolic health and enhanced the total antioxidant capacity. The present study investigated the influence of a 10-day fasting on markers of the redox status in 109 subjects. Reducing power, 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation(ABTS) radical scavenging capacity, and hydroxyl radical scavenging capacity increased significantly, and indicated an increase of circulating antioxidant levels. No differences were detected in superoxide scavenging capacity, protein carbonyls, and superoxide dismutase when measured at baseline and after 10 days of fasting. These findings were concomitant to a decrease in blood glucose, insulin, glycated hemoglobin (HbA1c), total cholesterol, low-density lipoprotein (LDL) and triglycerides as well as an increase in total cholesterol/high-density lipoprotein (HDL) ratio. In addition, the well-being index as well as the subjective energy levels increased, documenting a good tolerability. There was an interplay between redox and metabolic parameters since lipid peroxidation baseline levels (thiobarbituric acid reactive substances [TBARS]) affected the ability of long-term fasting to normalize lipid levels. A machine learning model showed that a combination of antioxidant parameters measured at baseline predicted the efficiency of the fasting regimen to decrease LDL levels. In conclusion, it was demonstrated that long-term fasting enhanced the endogenous production of antioxidant molecules, that act protectively against free radicals, and in parallel improved the metabolic health status. Our results suggest that the outcome of long-term fasting strategies could be depending on the baseline values of the antioxidative and metabolic status of subjects.

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Long-term fasting increases the antioxidant capacity and decreases oxidative damage.

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It improves the metabolic health status.

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High TBARS levels at baseline limit the LDL reduction during long-term fasting.

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The antioxidant status is related with the lipid lowering effect of long-term fasting.

Unravelling the health effects of fasting: a long road from obesity treatment to healthy life span increase and improved cognition

In recent years a revival of interest has emerged in the health benefits of intermittent fasting and long-term fasting, as well as of other related nutritional strategies. In addition to meal size and composition a new focus on time and frequency of meals has gained attention. The present review will investigate the effects of the main forms of fasting, activating the metabolic switch from glucose to fat and ketones (G-to-K), starting 12-16 h after cessation or strong reduction of food intake. During fasting the deactivation of mTOR regulated nutrient signalling pathways and activation of the AMP protein kinase trigger cell repair and inhibit anabolic processes. Clinical and animal studies have clearly indicated that modulating diet and meal frequency, as well as application of fasting patterns, e.g. intermittent fasting, periodic fasting, or long-term fasting are part of a new lifestyle approach leading to increased life and health span, enhanced intrinsic defences against oxidative and metabolic stresses, improved cognition, as well as a decrease in cardiovascular risk in both obese and non-obese subjects. Finally, in order to better understand the mechanisms beyond fasting-related changes, human studies as well as non-human models closer to human physiology may offer useful clues.KEY-MESSAGESBiochemical changes during fasting are characterised by a glucose to ketone switch, leading to a rise of ketones, advantageously used for brain energy, with consequent improved cognition.Ketones reduce appetite and help maintain effective fasting.Application of fasting patterns increases healthy life span and defences against oxidative and metabolic stresses.Today's strategies for the use of therapeutic fasting are based on different protocols, generally relying on intermittent fasting, of different duration and calorie intake.Long-term fasting, with durations between 5 and 21 days can be successfully repeated in the course of a year.

Chronic Inflammation in the Context of Everyday Life: Dietary Changes as Mitigating Factors

The lifestyle adopted by most people in Western societies has an important impact on the propensity to metabolic disorders (e.g., diabetes, cancer, cardiovascular disease, neurodegenerative diseases). This is often accompanied by chronic low-grade inflammation, driven by the activation of various molecular pathways such as STAT3 (signal transducer and activator of transcription 3), IKK (IκB kinase), MMP9 (matrix metallopeptidase 9), MAPK (mitogen-activated protein kinases), COX2 (cyclooxigenase 2), and NF-Kβ (nuclear factor kappa-light-chain-enhancer of activated B cells). Multiple intervention studies have demonstrated that lifestyle changes can lead to reduced inflammation and improved health. This can be linked to the concept of real-life risk simulation, since humans are continuously exposed to dietary factors in small doses and complex combinations (e.g., polyphenols, fibers, polyunsaturated fatty acids, etc.). Inflammation biomarkers improve in patients who consume a certain amount of fiber per day; some even losing weight. Fasting in combination with calorie restriction modulates molecular mechanisms such as m-TOR, FOXO, NRF2, AMPK, and sirtuins, ultimately leads to significantly reduced inflammatory marker levels, as well as improved metabolic markers. Moving toward healthier dietary habits at the individual level and in publicly-funded institutions, such as schools or hospitals, could help improving public health, reducing healthcare costs and improving community resilience to epidemics (such as COVID-19), which predominantly affects individuals with metabolic diseases.

Influence of Long-Term Fasting on Blood Redox Status in Humans

Fasting is increasingly practiced to improve health and general well-being, as well as for its cytoprotective effects. Changes in blood redox status, linked to the development of a variety of metabolic diseases, have been recently documented during calorie restriction and intermittent fasting, but not with long-term fasting (LF). We investigated some parameters of the blood redox profile in 109 subjects before and after a 10-day fasting period. Fasting resulted in a significant reduction in body weight, improved well-being and had a beneficial modulating effect on blood lipids and glucose regulation. We observed that fasting decreased lipid peroxidation (TBARS) and increased total antioxidant capacity (TAC) in plasma, concomitant with a uric acid elevation, known to be associated with fasting and did not cause gout attacks. Reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx) and catalase in erythrocytes did not show significant changes. In addition, reduction in body weight, waist circumference, and glucose levels were associated to a reduced lipid peroxidation. Similar results were obtained by grouping subjects on the basis of the changes in their GSH levels, showing that a period of 10 days fasting improves blood redox status regardless of GSH status in the blood.

TLR9 in MAFLD and NASH: At the Intersection of Inflammation and Metabolism

Toll-Like Receptor 9 (TLR9) is an ancient receptor integral to the primordial functions of inflammation and metabolism. TLR9 functions to regulate homeostasis in a healthy system under acute stress. The literature supports that overactivation of TLR9 under the chronic stress of obesity is a critical driver of the pathogenesis of NASH and NASH-associated fibrosis. Research has focused on the core contributions of the parenchymal and non-parenchymal cells in the liver, adipose, and gut compartments. TLR9 is activated by endogenous circulating mitochondrial DNA (mtDNA). Chronically elevated circulating levels of mtDNA, caused by the stress of overnutrition, are observed in obesity, metabolic dysfunction-associated fatty liver disease (MAFLD), and NASH. Clinical evidence is supportive of TLR9 overactivation as a driver of disease. The role of TLR9 in metabolism and energy regulation may have an underappreciated contribution in the pathogenesis of NASH. Antagonism of TLR9 in NASH and NASH-associated fibrosis could be an effective therapeutic strategy to target both the inflammatory and metabolic components of such a complex disease.