Feasibility of a Very Low Calorie Diet to Achieve a Sustainable 10% Weight Loss in Patients With Nonalcoholic Fatty Liver Disease

Ex Vivo Demonstration of a Novel Dual-Frequency Ultrasound Method for Quantitative Measurements of Liver Fat Content

OBJECTIVE

The rise in metabolic dysfunction-associated steatotic liver disease prevalence, closely linked with metabolic syndromes and obesity, demands accurate, cost-effective diagnostic methods for early-stage fat quantification in the liver. Here we demonstrate a novel dual-frequency ultrasound method that enables the quantitative measurement of liver fat fraction ex vivo and its correlation with actual fat content.

METHODS

A total of 24 Wistar rats were divided into four different groups, where three groups were given a high-fat diet for 2, 4, and 6 wk, and the last group was given a control diet for 6 wk. Livers were imaged with ultrasound ex vivo in a water bath with a dual-frequency ultrasound transducer and experimental imaging protocol implemented on the Verasonics Vantage research ultrasound scanner. Ultrasound data were post-processed to estimate the non-linear bulk elasticity parameter and the liver samples were analyzed with respect to fat fraction and triglycerides.

RESULTS

Rats given a high-fat diet had increased mean levels of liver fat compared with the control group. More importantly, correlation between the ultrasound-based estimation of the non-linear bulk elasticity parameter and fat fraction and triglycerides on an individual level was found to be strong (R2 = 0.81, p = 5.8 × 10-9 and R2 = 0.72, p = 3.6 × 10-7, respectively).

CONCLUSION

This study demonstrates the potential of the novel dual-frequency ultrasound method for the quantitative measurement of liver fat fraction in excised rat livers, showing great promise for this method to become clinically relevant in the diagnosis and follow-up of patients with fatty liver disease.

A Systematic Review and Meta-Analysis of the Effect of Caloric Restriction on Skeletal Muscle Mass in Individuals with, and without, Type 2 Diabetes

BACKGROUND

Severe caloric restriction interventions (such as very-low-calorie diets) are effective for inducing significant weight loss and remission of type 2 diabetes (T2DM). However, suggestions of associated significant muscle mass (MM) loss create apprehension regarding their widespread use. We conducted a systematic review and meta-analysis to provide a quantitative assessment of their effect on measures of MM in individuals with, or without, T2DM.

METHODS

EMBASE, Medline, Pubmed, CINAHL, CENTRAL and Google Scholar were systematically searched for studies involving caloric restriction interventions up to 900 kilocalories per day reporting any measure of MM, in addition to fat mass (FM) or body weight (BW).

RESULTS

Forty-nine studies were eligible for inclusion, involving 4785 participants. Individuals with T2DM experienced significant reductions in MM (WMD -2.88 kg, 95% CI: -3.54, -2.22; p < 0.0001), although this was significantly less than the reduction in FM (WMD -7.62 kg, 95% CI: -10.87, -4.37; p < 0.0001). A similar pattern was observed across studies involving individuals without T2DM. MM constituted approximately 25.5% of overall weight loss in individuals with T2DM, and 27.5% in individuals without T2DM. Subgroup analysis paradoxically revealed greater BW and FM reductions with less restrictive interventions.

CONCLUSIONS

Our review suggests that caloric restriction interventions up to 900 kilocalories per day are associated with a significant reduction in MM, albeit in the context of a significantly greater reduction in FM. Furthermore, MM constituted approximately a quarter of the total weight loss. Finally, our data support the use of less restrictive interventions, which appear to be more beneficial for BW and FM loss.

Impact of Simulated Caloric Reduction on Nutrient Adequacy Among U.S. Adults with Overweight or Obesity (National Health and Nutrition Examination Survey [NHANES] 2015-2018)

BACKGROUND

Current guidelines for the treatment of obesity recommend dietary restriction to create a caloric deficit, and caloric reductions of 16% to 68% have been achieved in adults with overweight or obesity engaging in intentional weight loss programs.

OBJECTIVES

This study models the impact of simulated caloric reduction on nutrient adequacy among U.S. adults ≥19 y with overweight or obesity using National Health and Nutrition Examination Survey data (2015-2018).

METHODS

Four levels of caloric reduction (20%, 30%, 40%, and 50%) were modeled by prorating daily calorie intake such that usual intakes of 14 nutrients were reduced proportional to caloric reduction. The percentages below the estimated average requirement (EAR) or above the adequate intake (AI) were estimated at each level of caloric reduction, with and without dietary supplement use. Differences across percentages of simulated caloric reductions were determined using nonoverlapping confidence intervals of the means (97.5th percentile confidence intervals were used to approximate P < 0.05).

RESULTS

There were significant differences (P < 0.05) in percentages below the EAR (above the AI) between sequential levels of simulated caloric reduction for most of the nutrients analyzed (protein, vitamins A, B-6, folate, and C, calcium, iron, magnesium, potassium, and zinc). For example, after a simulated 30% caloric reduction, 25%-40% of the population had intakes below the EAR for protein, vitamin B-6, and zinc, and 75%-91% of the population had intakes below the EAR for vitamin A, calcium, and magnesium (vs. 4%-18% and 45%-56%, respectively, without caloric reduction). With the inclusion of dietary supplements, percentages below the EAR for all nutrients (except protein) were lower than those for food alone.

CONCLUSIONS

Caloric reduction may exacerbate nutrient inadequacies among adults with overweight or obesity. Inclusion of nutrient-dense foods, fortified foods, specially formulated products, and/or dietary supplements should be considered for those on calorie-restricted diets for long-term weight loss.

The latest evidence and clinical guidelines for use of meal replacements in very-low-calorie diets or low-calorie diets for the treatment of obesity

Obesity is a complex chronic disease with increasing prevalence across the globe. Medical nutrition therapy (MNT) is an important component of obesity treatment, and low-calorie diets (LCDs) and very-low-calorie diets (VLCDs) are part of the MNT toolbox. This narrative review focuses on the latest evidence and clinical guidelines regarding the use and impact of meal replacements (MRs) as part of LCDs/VLCDs for the treatment of obesity and some associated complications. MRs can be used in conjunction with food as partial diet replacement (PDR) or can be used exclusively to serve as the sole source of dietary energy (total diet replacement [TDR]). Use of MR may be associated with better control of cravings and hunger typically observed during reduced calorie intake through effects of ketosis or stimuli narrowing, although the exact mechanisms for these effects remain unclear. Several clinical guidelines have endorsed the use of MRs as a part of MNT for obesity, primarily based on evidence that shows an average weight reduction of ~10 kg or more with TDR over at least 12 months in large, randomized controlled trials. When compared to usual care controls, these effects are 6-8 kg greater, and when compared to food-based diets, the effects are nearly twice the effect of a food-based diet. MR-based diets have been found to be safe and associated with improvements in quality of life. These diets are also effective for improving key cardiometabolic health outcomes, including dysglycaemia, blood pressure, lipids, and metabolic associated fatty liver. The effectiveness, safety, and associated health improvement makes MRs use a valuable strategy for several higher risk clinical scenarios where weight reduction is indicated.

Altered lipid metabolism and the development of metabolic-associated fatty liver disease

PURPOSE OF REVIEW

An increasing amount of research has underscored the significant role of lipoproteins in the pathogenesis of metabolic-associated fatty liver disease (MAFLD). This comprehensive review examines the intricate relationship between lipoprotein abnormalities and the development of MAFLD.

RECENT FINDINGS

Atherogenic dyslipidemia seen in insulin resistance states play a significant role in initiating and exacerbating hepatic lipid accumulation. There are also specific genetic factors ( PNPLA3 , TM6SF2 , MBOAT7 , HSD17B13 , GCKR- P446L) and transcription factors (SREBP-2, FXR, and LXR9) that increase susceptibility to both lipoprotein disorders and MAFLD. Most monogenic primary lipid disorders do not cause hepatic steatosis unless accompanied by metabolic stress. Hepatic steatosis occurs in the presence of secondary systemic metabolic stress in conjunction with predisposing environmental factors that lead to insulin resistance. Identifying specific aberrant lipoprotein metabolic factors promoting hepatic fat accumulation and subsequently exacerbating steatohepatitis will shed light on potential targets for therapeutic interventions.

SUMMARY

The clinical implications of interconnection between genetic factors and an insulin resistant environment that predisposes MAFLD is many fold. Potential therapeutic strategies in preventing or mitigating MAFLD progression include lifestyle modifications, pharmacological interventions, and emerging therapies targeting aberrant lipoprotein metabolism.

Weight loss treatment for COVID-19 in patients with NCDs: a pilot prospective clinical trial

COVID-19 comorbid with noncommunicable chronic diseases (NCDs) complicates the diagnosis, treatment, and prognosis, and increases the mortality rate. The aim is to evaluate the effects of a restricted diet on clinical/laboratory inflammation and metabolic profile, reactive oxygen species (ROS), and body composition in patients with COVID-19 comorbid with NCDs. We conducted a 6-week open, pilot prospective controlled clinical trial. The study included 70 adult patients with COVID-19 comorbid with type 2 diabetes (T2D), hypertension, or nonalcoholic steatohepatitis (NASH).

INTERVENTIONS

a restricted diet including calorie restriction, hot water drinking, walking, and sexual self-restraint.

PRIMARY ENDPOINTS

COVID-19 diagnosis by detecting SARS-CoV-2 genome by RT-PCR; weight loss in Main group; body temperature; C-reactive protein. Secondary endpoints: the number of white blood cells; erythrocyte sedimentation rate; adverse effects during treatment; fasting blood glucose, glycosylated hemoglobin A1c (HbA1c), systolic/diastolic blood pressure (BP); blood lipids; ALT/AST, chest CT-scan. In Main group, patients with overweight lost weight from baseline (- 12.4%; P < 0.0001); 2.9% in Main group and 7.2% in Controls were positive for COVID-19 (RR: 0.41, CI: 0.04-4.31; P = 0.22) on the 14th day of treatment. Body temperature and C-reactive protein decreased significantly in Main group compared to Controls on day 14th of treatment (P < 0.025). Systolic/diastolic BP normalized (P < 0.025), glucose/lipids metabolism (P < 0.025); ALT/AST normalized (P < 0.025), platelets increased from baseline (P < 0.025), chest CT (P < 0.025) in Main group at 14 day of treatment. The previous antidiabetic, antihypertensive, anti-inflammatory, hepatoprotective, and other symptomatic medications were adequately decreased to completely stop during the weight loss treatment. Thus, the fast weight loss treatment may be beneficial for the COVID-19 patients with comorbid T2D, hypertension, and NASH over traditional medical treatment because, it improved clinical and laboratory/instrumental data on inflammation; glucose/lipid metabolism, systolic/diastolic BPs, and NASH biochemical outcomes, reactive oxygen species; and allowed patients to stop taking medications.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05635539 (02/12/2022): https://clinicaltrials.gov/ct2/show/NCT05635539?term=NCT05635539&draw=2&rank=1 .

Dietary composition and its association with metabolic dysfunction-associated fatty liver disease among Chinese adults: A cross-sectional study

BACKGROUND AND STUDY AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) has become the most common cause of chronic liver disease worldwide. Diet plays a critical role in the prevention and treatment of MAFLD. Our hypothesis was that the intake of some macronutrients, vitamins, or mineral elements is associated with MAFLD.

PATIENTS AND METHODS

Patients with MAFLD can be diagnosed based on the evidence of hepatic steatosis and if they meet any of the three additional criteria of overweight/obesity, diabetes mellitus, or metabolic dysregulation. Diets were recorded using photographs and diaries of meals for seven consecutive days. The consumed dietary composition was compared with the recommended intake according to the China Food Composition Tables (Standard Edition) version 2019 and the Chinese Dietary Reference Intakes version 2013, and its association with MAFLD was assessed by logistical regression analyses.

RESULTS

A total of 229 MAFLD patients and 148 healthy controls were included in this study. MAFLD patients, compared with that by non-MAFLD participants, consumed more polyunsaturated fatty acids (PUFAs) (p < 0.001), vitamin E (p < 0.001), and iron (p = 0.008). The intake of PUFAs (OR = 1.070, 95 % CI: 1.017-1.127, p = 0.009) and vitamin E (OR = 1.100, 95 % CI: 1.018-1.190, p = 0.016) was positively associated with MAFLD. In addition, the percentages of individuals who consumed PUFAs (p = 0.006), vitamin E (p < 0.001), or iron (p = 0.046) above the recommended intake were higher among the individuals with MAFLD. Daily intake of PUFAs > 11 % (OR = 2.328, 95 % CI: 1.290-4.201, p = 0.005) and vitamin E > 14 mg (OR = 2.189, 95 % CI: 1.153-4.158, p = 0.017) was positively correlated with MAFLD.

CONCLUSIONS

Patients with MAFLD consumed more PUFAs, vitamin E, and iron in their daily diet. Excessive consumption of PUFAs and vitamin E might be independent risk factors for the incidence of MAFLD.

Effect of a Low-Calorie Dietary Intervention on Liver Health and Body Weight in Adults with Metabolic-Dysfunction Associated Steatotic Liver Disease (MASLD) and Overweight/Obesity: A Systematic Review and Meta-Analysis

INTRODUCTION

Metabolic-dysfunction Associated Steatotic Liver Disease (MASLD) is a common cause of chronic liver disease. This review assessed the efficacy of a Low-Calorie Diet (LCD) on liver health and body weight in people living with MASLD and obesity.

METHODS

The study was registered with PROSPERO (CRD42021296501), and a literature search was conducted using multiple databases. The key inclusion criteria were randomised controlled trials or cohort studies, obesity/overweight and MASLD. Two authors screened abstracts, reviewed full texts and performed data extraction and quality assessment. The primary outcome was the change in the serum ALT, and secondary outcomes included the changes in the serum AST, intrahepatic lipid content (IHL), quantified non-invasively via MRI/MRS, and body weight.

RESULTS

Fifteen studies were included. The LCD reduced body weight by 9.1 kg versus the control (95%CI: -12.4, -5.8) but not serum ALT (-5.9 IU/L, -13.9, 2.0). Total Dietary Replacement (TDR) reduced IHL by -9.1% vs. the control (-15.6%, -2.6%). The Mediterranean-LCD for ≥12 months reduced ALT (-4.1 IU/L, -7.6, -0.5) and for 24 months reduced liver stiffness versus other LCDs. The Green-Mediterranean-LCD reduced IHL, independent of body weight. Limited studies assessed those of Black or Asian ethnicity, and there was heterogeneity in the methods assessing the liver fat content and fibrosis.

CONCLUSIONS

In people with MASLD and obesity, an LCD intervention reduces IHL and body weight. Trials should focus on the recruitment of Black and Asian ethnicity participants.

Obesity and malnutrition in children and adults: A clinical review

Background

In the U.S., children and adults are consuming more low-nutrient foods with added sugar and excess fats as compared to healthy, high-quality calories and micronutrients. This diet is increasing the prevalence of malnutrition and nutritional deficiencies, despite high calorie intake. This is a review of the common micronutrient deficiencies, the risk factors for malnutrition, dietary plans, and the health consequences in children and adults with obesity in the U.S.

Methods

This clinical review of literature was performed on the MEDLINE (PubMed) search engine. A total of 1391 articles were identified and after review, a total of 130 were found to be most pertinent.

Discussion

The most common micronutrient deficiencies found in patients with obesity were vitamin A, thiamine (B1), folate (B9), cobalamin (B12), vitamin D, iron, calcium, and magnesium, especially prior and after bariatric surgery. Diets that produced the most weight reduction also further puts these individuals at risk for worsening malnutrition. Malnutrition and micronutrient deficiencies can worsen health outcomes if not properly managed.

Conclusion

Adequate screening and awareness of malnutrition can improve the health outcomes in patients with obesity. Physiologic changes in response to increased adiposity and inadequate intake increase this population's risk of adverse health effects. Malnutrition affects the individual and contributes to worse public health outcomes. The recommendations for screening for malnutrition are not exclusive to individuals undergoing bariatric procedures and can improve the health outcomes of any patient with obesity. However, clearly, improved nutritional status can assist with metabolism and prevent adverse nutritional outcomes post-bariatric surgery. Clinicians should advise on proper nutrition and be aware of diets that worsen deficiencies.

Serum levels of fibrogenesis biomarkers reveal distinct endotypes predictive of response to weight loss in advanced nonalcoholic fatty liver disease

BACKGROUND

NAFLD is associated with activation of fibroblasts and hepatic fibrosis. Substantial patient heterogeneity exists, so it remains challenging to risk-stratify patients. We hypothesized that the amount of fibroblast activity, as assessed by circulating biomarkers of collagen formation, can define a "high-risk, high-fibrogenesis" patient endotype that exhibits greater fibroblast activity and potentially more progressive disease, and this endotype may be more amendable to dietary intervention.

METHODS

Patients with clinically confirmed advanced NAFLD were prescribed a very low-calorie diet (VLCD) intervention (∼800 kcal/d) to induce weight loss, achieved using total diet replacement. Serum markers of type III (PRO-C3) and IV collagen (PRO-C4) fibrogenesis were assessed at baseline every second week until the end of the VLCD, and 4 weeks post-VLCD and at 9 months follow-up.

RESULTS

Twenty-six subjects had a mean weight loss of 9.7% with VLCD. This was associated with significant improvements in liver biochemistry. When stratified by baseline PRO-C3 and PRO-C4 into distinct fibrosis endotypes, these predicted substantial differences in collagen fibrogenesis marker dynamics in response to VLCD. Patients in the high activity group (PRO-C3 >11.4 ng/mL and/or PRO-C4 >236.5 ng/mL) exhibited a marked reduction of collagen fibrogenesis, ranging from a 40%-55% decrease in PRO-C3 and PRO-C4, while fibrogenesis remained unchanged in the low activity group. The biochemical response to weight loss was substantially greater in patients a priori exhibiting a high fibroblast activity endotype in contrast to patients with low activity.

CONCLUSIONS

Thus, the likelihood of treatment response may be predicted at baseline by quantification of fibrogenesis biomarkers.

Metabolic-Associated Fatty Liver Disease and Diabetes: A Double Whammy

Metabolic-associated fatty liver disease (MAFLD) is the hepatic manifestation of metabolic syndrome and affects about 55% of people living with diabetes. MAFLD has been shown to be an individual risk factor for cardiovascular disease and its associated mortality. Although common, MAFLD is often underdiagnosed and not given adequate attention during clinical visits. This review highlights the most recent literature available on the evaluation and management of MAFLD in the presence of diabetes. The more recently available antidiabetic agents including glucagon-like peptide-1 analogs and sodium-glucose cotransporter-2 inhibitors have been shown to effectively manage both diabetes and MAFLD.

A low-energy total diet replacement program demonstrates a favorable safety profile and improves liver disease severity in nonalcoholic steatohepatitis

OBJECTIVE

Low-energy diets are used to treat obesity and diabetes, but there are fears that they may worsen liver disease in patients with nonalcoholic steatohepatitis (NASH) and significant-to-advanced fibrosis.

METHODS

In this 24-week single-arm trial, 16 adults with NASH, fibrosis, and obesity received one-to-one remote dietetic support to follow a low-energy (880 kcal/d) total diet replacement program for 12 weeks and stepped food reintroduction for another 12 weeks. Liver disease severity was blindly evaluated (magnetic resonance imaging proton density fat fraction [MRI-PDFF], iron-corrected T1 [cT1], liver stiffness on magnetic resonance elastography [MRE], and liver stiffness on vibration-controlled transient elastography [VCTE]). Safety signals included liver biochemical markers and adverse events.

RESULTS

A total of 14 participants (87.5%) completed the intervention. Weight loss was 15% (95% CI: 11.2%-18.6%) at 24 weeks. Compared with baseline, MRI-PDFF reduced by 13.1% (95% CI: 8.9%-16.7%), cT1 by 159 milliseconds (95% CI: 108-216.5), MRE liver stiffness by 0.4 kPa (95% CI: 0.1-0.8), and VCTE liver stiffness by 3.9 kPa (95% CI: 2.6-7.2) at 24 weeks. The proportions with clinically relevant reductions in MRI-PDFF (≥30%), cT1 (≥88 milliseconds), MRE liver stiffness (≥19%), and VCTE liver stiffness (≥19%) were 93%, 77%, 57%, and 93%, respectively. Liver biochemical markers improved. There were no serious intervention-related adverse events.

CONCLUSIONS

The intervention demonstrates high adherence, favorable safety profile, and promising efficacy as a treatment for NASH.

What's New in the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem due to its high incidence and consequences. In view of the existing controversies, new therapeutic options for NAFLD are still being sought. Therefore, the aim of our review was to evaluate the recently published studies on the treatment of NAFLD patients. We searched for articles in the PubMed database using appropriate terms, including "non-alcoholic fatty liver disease", "nonalcoholic fatty liver disease", "NAFLD", "diet", "treatment", "physical activity", "supplementation", "surgery", "overture" and "guidelines". One hundred forty-eight randomized clinical trials published from January 2020 to November 2022 were used for the final analysis. The results show significant benefits of NAFLD therapy associated with the use of not only the Mediterranean but also other types of diet (including low-calorie ketogenic, high-protein, anti-inflammatory and whole-grain diets), as well as enrichment with selected food products or supplements. Significant benefits in this group of patients are also associated with moderate aerobic physical training. The available therapeutic options indicate, above all, the usefulness of drugs related to weight reduction, as well as the reduction in insulin resistance or lipids level and drugs with anti-inflammatory or antioxidant properties. The usefulness of therapy with dulaglutide and the combination of tofogliflozin with pioglitazone should be emphasized. Based on the results of the latest research, the authors of this article suggest a revision of the therapeutic recommendations for NAFLD patients.

Understanding NAFLD: From Case Identification to Interventions, Outcomes, and Future Perspectives

While non-alcoholic fatty liver disease (NAFLD) is a prevalent and frequent cause of liver-related morbidity and mortality, it is also strongly associated with cardiovascular disease-related morbidity and mortality, likely driven by its associations with insulin resistance and other manifestations of metabolic dysregulation. However, few satisfactory pharmacological treatments are available for NAFLD due in part to its complex pathophysiology, and challenges remain in stratifying individual patient's risk for liver and cardiovascular disease related outcomes. In this review, we describe the development and progression of NAFLD, including its pathophysiology and outcomes. We also describe different tools for identifying patients with NAFLD who are most at risk of liver-related and cardiovascular-related complications, as well as current and emerging treatment options, and future directions for research.

Management of metabolic-associated fatty liver disease: The diabetology perspective

The metabolic syndrome as a consequence of the obesity pandemic resulted in a substantial increase in the prevalence of metabolic-associated fatty live disease (MAFLD) and type 2 diabetes mellitus (T2DM). Because of the similarity in pathobiology shared between T2DM and MAFLD, both disorders coexist in many patients and may potentiate the disease-related outcomes with rapid progression and increased complications of the individual diseases. In fact, awareness about this coexistence and the risk of complications are often overlooked by both hepatologists and diabetologists. Management of these individual disorders in a patient should be addressed wholistically using an appropriate multidisciplinary team approach involving both the specialists and, when necessary, liaising with dieticians and surgeons. This comprehensive review is to compile the current evidence from a diabetologist's perspective on MAFLD and T2DM and to suggest optimal management strategies.

The use of very low-calorie diets in subjects with obesity complicated with nonalcoholic fatty liver disease: A scoping review

This scoping review synthesizes the existing research on the use of very low-calorie diets (VLCDs) in subjects with nonalcoholic fatty liver disease (NAFLD) and end-stage liver disease (ESLD). 19 studies were included, of which 5 were clinical trials, 11 were cohort studies, 1 was a case-control study, and 2 were case series totaling 968 subjects. About 17 studies were focused on patients with NAFLD while the two case series described in patients with ESLD on the transplant list or post-liver transplant. Six studies included subjects managed with VLCDs prior bariatric surgery. Most studies were short term and demonstrated acute improvement of diverse liver biomarkers including liver function tests, indices of hepatosteatosis and reduction in liver size. Adherence rates in these studies were between 69% and 93%. Eight studies did not report any adverse events and four subjects were reported to have discontinued VLCD due to adverse effects in two different studies. Aggregated adverse events were mild. Treatments based on VLCD in subjects with NAFLD seem to be safe and tolerable but can result in mild adverse effects. The findings of this scoping review suggest that the use of VLCD in patients with obesity complicated with NAFLD and potentially in ESLD appear to be effective to induce weight loss and to acutely reduce hepatosteatosis.

The impact of health status, diet and lifestyle on non-alcoholic fatty liver disease: Narrative review

Non-alcoholic fatty liver disease (NAFLD) is defined as the abnormal accumulation of triglycerides in the liver. NAFLD has a global prevalence of almost 30%, while incidence is rising with increasing levels of obesity, type 2 diabetes mellitus (T2DM) and metabolic syndrome. Nutrition plays a significant role in both the prevention and treatment of NAFLD. Therefore, the aim of this literature review is to explore the associations between dietary, lifestyle and other risk factors and the risk for developing NAFLD. Dietary patterns, lifestyle behaviours, comorbidities, or a combination of any may contribute to either the progression or prevention of NAFLD. Having diabetes, hypertension, or having obesity might increase the progression of NAFLD if not well treated and controlled. Diet influences the progression of NAFLD; following a western diet or simply a high-fat diet may contribute to the worsening of NAFLD and further progression to non-alcoholic steatohepatitis (NASH) and cirrhosis in later stages. On the other hand, the Mediterranean diet is the gold standard for both the treatment and prevention of NAFLD. Social behaviours, such as smoking, caffeine consumption and physical activity also play a role in the pathophysiology of NAFLD. Nutrition contributes significantly to the prevention or treatment of NAFLD, since this disease can be managed by diet and physical activity. However, further studies are still needed for a better understanding of the mechanisms of action. Randomized control trials are also needed to confirm findings in observational studies.

Effectiveness and Tolerability of a Two-Week Hypocaloric Protein-Rich Diet Prior to Obesity Surgery with Two Different Diet Interventions: a Prospective Randomized Trial

Purpose

Preoperative very low-calorie diets (VLCDs) have been shown to reduce liver volume and improve bariatric surgery safety. Here, we compare two VLCD that differ in macronutrient composition.

Material/Methods

Ninety patients awaiting obesity surgery were included in a prospective, open-label, randomized mono-centre trial comparing the effects of 2-week preoperative VLCDs: BCM Diät™ (diet 1) versus Optifast™ (diet 2).

Results

Data from 33 patients in diet 1 and 36 in diet 2 could be analysed. There was no significant difference between the two diet intervention arms on outcome parameters. Overall, both VLCD strategies led to a mean weight reduction of 5.24 [4.72–5.76] kg (p < 0.001), mean excess weight loss was 8.2 [7.4–9.1] % (p < 0.001). BMI reduction was 1.81 [1.63–1.99] kg/m² (p < 0.001). Over all patients, the liver volume was reduced by 397 [329–466] ml (p < 0.001), which corresponds to 14.6 [12.4; 16.8] %. Liver fat content was significantly reduced by 18.35 [8.98–27.71] %. Reduction of body weight correlates with liver volume loss.

In addition, hip/waist circumferences, body fat and fat-free mass decreased significantly. We found an increase of ALAT/ASAT and a significant decrease of triglycerides, LDL-cholesterol and HbA1c. Parameters of inflammatory were significantly reduced upon VLCD.

Conclusion

Independently of the macronutrient composition, VLCD leads to a significant decrease of body weight, reduction of liver volume and improved parameters of inflammation, glucose and lipid metabolism. Preoperative diets are widely used in conditioning; however, VLCD should be considered as option for patients with obesity undergoing other abdominal surgeries.

Graphical abstract

Effect of intensive weight-loss intervention on metabolic, ultrasound and anthropometric parameters among patients with obesity and non-alcoholic fatty liver disease: an RCT

Background

Lifestyle intervention is the mainstay therapy for Non-Alcoholic Fatty Liver Disease (NAFLD). We aimed to assess the efficacy of an intensive (9 contact points in 6 months) weight-loss intervention among patients with obesity (BMI 25–39.9 kg/m²) and NAFLD in north India.

Methods

A total of 140 patients (18–60 years) with obesity and NAFLD were randomized into intervention (n = 70) and control (n = 70) groups, at a tertiary-care hospital. Weight, anthropometric parameters, Controlled Attenuation Parameter (CAP), Liver Stiffness Measurement (LSM), liver enzymes, grade of fatty liver and HOMA-IR were measured at baseline (T₀) and 6 months (T₆). There was a high drop-out, exacerbated by the Covid-19 pandemic. Completers comprised of 59 participants (n = 30 intervention, n = 29 control). Intention to treat analysis was done.

Results

At T₆, ALT normalized in significantly higher (p = 0.03) number of cases in the intervention arm (66.7%) versus control arm (18.2%). No significant improvement was seen in other metabolic, ultrasound or anthropometric outcomes. Weight (p < 0.001), AST (p = 0.01), ALT (p = 0.02), body fat% (p < 0.001), WC (p < 0.001) and CAP (p < 0.001) significantly improved within the intervention arm along with a trend of improvement in steatosis and HOMA-IR. Control group showed significant decrease in weight (p < 0.001), WC (p < 0.001) and CAP (p = 0.02). Twice the number of patients in intervention arm (46.7%) lost ≥5% weight, compared to control arm (24.1%) (p = 0.07).

Conclusion

The intensive weight-loss intervention was not effective in improving the treatment outcomes among patients with obesity and NAFLD. However, given the potential of our intervention, we recommend larger trials with more intensive weight-loss interventions.

Current considerations for clinical management and care of non-alcoholic fatty liver disease: Insights from the 1st International Workshop of the Canadian NASH Network (CanNASH)

Non-alcoholic fatty liver disease (NAFLD) affects approximately 8 million Canadians. NAFLD refers to a disease spectrum ranging from bland steatosis to non-alcoholic steatohepatitis (NASH). Nearly 25% of patients with NAFLD develop NASH, which can progress to liver cirrhosis and related end-stage complications. Type 2 diabetes and obesity represent the main risk factors for the disease. The Canadian NASH Network is a national collaborative organization of health care professionals and researchers with a primary interest in enhancing understanding, care, education, and research around NAFLD, with a vision of best practices for this disease state. At the 1st International Workshop of the CanNASH network in April 2021, a joint event with the single topic conference of the Canadian Association for the Study of the Liver (CASL), clinicians, epidemiologists, basic scientists, and community members came together to share their work under the theme of NASH. This symposium also marked the initiation of collaborations between Canadian and other key opinion leaders in the field representative of international liver associations. The main objective is to develop a policy framework that outlines specific targets, suggested activities, and evidence-based best practices to guide provincial, territorial, and federal organizations in developing multidisciplinary models of care and strategies to address this epidemic.

Diet and Gut Microbiota Interaction-Derived Metabolites and Intrahepatic Immune Response in NAFLD Development and Treatment

Nonalcoholic fatty liver disease (NAFLD) with pathogenesis ranging from nonalcoholic fatty liver (NAFL) to the advanced form of nonalcoholic steatohepatitis (NASH) affects about 25% of the global population. NAFLD is a chronic liver disease associated with obesity, type 2 diabetes, and metabolic syndrome, which is the most increasing factor that causes hepatocellular carcinoma (HCC). Although advanced progress has been made in exploring the pathogenesis of NAFLD and penitential therapeutic targets, no therapeutic agent has been approved by Food and Drug Administration (FDA) in the United States. Gut microbiota-derived components and metabolites play pivotal roles in shaping intrahepatic immunity during the progression of NAFLD or NASH. With the advance of techniques, such as single-cell RNA sequencing (scRNA-seq), each subtype of immune cells in the liver has been studied to explore their roles in the pathogenesis of NAFLD. In addition, new molecules involved in gut microbiota-mediated effects on NAFLD are found. Based on these findings, we first summarized the interaction of diet-gut microbiota-derived metabolites and activation of intrahepatic immunity during NAFLD development and progression. Treatment options by targeting gut microbiota and important molecular signaling pathways are then discussed. Finally, undergoing clinical trials are selected to present the potential application of treatments against NAFLD or NASH.

Effective Treatment of Nonalcoholic Fatty Liver Disease Using a Community-Based Weight Management Program

Introduction

Obesity-related gastrointestinal disorders including nonalcoholic fatty liver disease (NAFLD) and gastroesophageal reflux disease (GERD) are more frequent and usually present earlier than type 2 diabetes mellitus (T2DM) and cardiovascular disorders. This provides an opportunity for the gastroenterologist to intervene early with an effective weight-loss therapy. We evaluated the outcomes of a multifaceted, community-based gastroenterologist-supervised weight management program compared with patient-directed weight-loss efforts after physician advice. The program is aimed at achieving a 10% total body weight (TBW) loss at three months, a known determinant for NAFLD regression.

Methods

This is a retrospective pre- and post-intervention study of NAFLD patients, who participated in a medically supervised weight management program in the period between May 2017 and May 2019. The program is comprised of a very-low-calorie (800 kcal/day) meal replacement diet, a recommended medical fitness program, and weekly behavioral support groups. Patients are followed on monthly basis and slowly transitioned to a whole food plant-based or Mediterranean diet after three months of participation. Patients’ weight trends driven by self-directed efforts to lose weight after physician advice were collected based on historical data up to two years prior to program participation. The primary outcome was defined as percentage TBW loss at three months under medical supervision (post-intervention) compared with patient-directed weight-loss efforts (pre-intervention). The secondary outcomes included percentage TBW loss in relation to behavioral support group attendance and improvement in GERD and T2DM disease status after program participation. Linear mixed and linear regression models were used to assess for a statistically significant difference in percentage TBW loss. Statistical significance was defined as p < 0.05.

Results

A total of 114 NAFLD patients (mean age 55 years, mean BMI 39 kg/m², 77 females, and 37 males) completed at least three months of follow-up and were included in the study. Of those, 89 patients had a documented three-month office visit. At three months, 65% of patients had lost at least 10% of their TBW. Percentage TBW loss under medical supervision was noted to be significantly higher and occurred at a faster rate over three months when compared with patient-directed efforts after physician advice (p < 0.001). Patients who attended the behavioral support groups ≥ 50% of the time had a 3% higher TBW loss at three months compared with patients who attended <50% of the time (p = 0.006). Approximately, 52% of patients with GERD and 38% of patients with T2DM had symptoms improvement and/or medication reduction at their three-month follow-up visit.

Conclusion

A multifaceted, community-based, gastroenterologist supervised weight management program is effective in achieving a clinically significant TBW loss of at least 10% within three months of participation. This weight loss was greater and occurred at a faster rate when compared with patient-directed efforts. Additionally, improvement in GERD and T2DM disease status was noted in 52% and 38% of patients with these conditions, respectively. Further community-based studies of a larger scale are needed to determine the sustainability of this weight loss over one year.

Sustainability of diet-based moderate calorie restriction among obese patients with metabolic-associated fatty liver disease

Background and Aim

The long-term sustainability of weight loss continues to be a subject of investigation. This study was designed to examine the effects of weight loss and the long-term sustainability of lifestyle modifications among obese patients with metabolic-associated fatty liver disease (MAFLD).

Materials and Methods

A total of 40 patients who were prescribed a hypocaloric diet (~500 calories reduction for each patient), and who were followed up for 12 weeks in 4 face-to-face interviews were enrolled in the study. The patients were contacted at the 36th month, and their current weight was recorded.

Results

The mean weight at baseline of 87±13 kg decreased to 79±11 kg after 12 weeks of intervention (p<0.001). The mean weight at the 36th month did not significantly differ from that measured at the baseline (p=0.563). The mean controlled attenuation parameter decreased from 320±13 dB/m to 273±37 dB/m (p<0.001), while the median liver stiffness measurement decreased from 8.7 kPa (3.6-45.7 kPa) to 5.7 kPa (2.2-29.9 kPa) (p<0.001).

Conclusion

Strict follow-up through nutritional consultation can help achieve weight loss in obese patients with MAFLD. However, for long-term results, the collaboration of nutritionists and gastroenterologists is essential to prevent weight regain.

NAFLD-Related Hepatocarcinoma: The Malignant Side of Metabolic Syndrome

Hepatocellular carcinoma (HCC) is the seventh most common cancer worldwide and the second leading cause of cancer-related mortality. HCC typically arises within a cirrhotic liver, but in about 20% of cases occurs in absence of cirrhosis. Among non-cirrhotic risk factors, non-alcoholic fatty liver disease (NAFLD) currently represents the most important emerging cause of HCC in developed countries. It has been estimated that annual incidence of HCC among patients with non-cirrhotic NAFLD is approximately 0.1-1.3 per 1000 patients/year and ranges from 0.5% to 2.6% among patients with non-alcoholic steatohepatitis (NASH) cirrhosis. However, only a few clinical trials enrolling HCC patients actually distinguished NAFLD/NASH-related cases from other non-cirrhotic causes and therefore evidence is still lacking in this subset of patients. This review aims to describe the biology underpinning NAFLD development, to investigate the main molecular pathways involved in its progression to NASH and HCC and to describe how different pathogenetic mechanisms underlying the onset of HCC can have an impact in clinical practice. We hereby also provide an overview of current HCC treatment options, with a particular focus on the available data on NAFLD-related cases in practice-changing clinical trials.

Factors associated with engagement and adherence to a low-energy diet to promote 10% weight loss in patients with clinically significant non-alcoholic fatty liver disease

Objective

Clinical guidelines recommend weight loss to manage non-alcoholic fatty liver disease (NAFLD). However, the majority of patients find weight loss a significant challenge. We identified factors associated with engagement and adherence to a low-energy diet (LED) as a treatment option for NAFLD.

Design

23 patients with NAFLD enrolled in a LED (~800 kcal/day) were individually interviewed. Transcripts were thematically analysed.

Results

14/23 patients achieved ≥10% weight loss, 18/23 achieved ≥7% weight loss and 19/23 achieved ≥5% weight loss. Six themes were generated from the data. A desire to achieve rapid weight loss to improve liver health and prevent disease progression was the most salient facilitator to engagement. Early and significant weight loss, accountability to clinicians and regular appointments with personalised feedback were facilitators to engagement and adherence. The desire to receive positive reinforcement from a consultant was a frequently reported facilitator to adherence. Practical and emotional support from friends and family members was critically important outside of the clinical setting. Irregular working patterns preventing attendance at appointments was a barrier to adherence and completion of the intervention.

Conclusions

Engagement and adherence to a LED in patients with NAFLD were encouraged by early and rapid weight loss, personalised feedback and positive reinforcement in the clinical setting combined with ongoing support from friends and family members. Findings support those identified in patients who completed a LED to achieve type 2 diabetes remission and highlight the importance of behaviour change support during the early stages of a LED to promote adherence.

Beyond the Paradigm of Weight Loss in Non-Alcoholic Fatty Liver Disease: From Pathophysiology to Novel Dietary Approaches

Current treatment recommendations for non-alcoholic fatty liver disease (NAFLD) rely heavily on lifestyle interventions. The Mediterranean diet and physical activity, aiming at weight loss, have shown good results in achieving an improvement of this liver disease. However, concerns related to compliance and food accessibility limit the feasibility of this approach, and data on the long-term effects on liver-related outcomes are lacking. Insulin resistance is a central aspect in the pathophysiology of NAFLD; therefore, interventions aiming at the improvement of insulin sensitivity may be preferable. In this literature review, we provide a comprehensive summary of the available evidence on nutritional approaches in the management of NAFLD, involving low-calorie diets, isocaloric diets, and the novel schemes of intermittent fasting. In addition, we explore the harmful role of single nutrients on liver-specific key metabolic pathways, the role of gene susceptibility and microbiota, and behavioral aspects that may impact liver disease and are often underreported in clinical setting. At present, the high variability in terms of study populations and liver-specific outcomes within nutritional studies limits the generalizability of the results and highlights the urgent need of a tailored and standardized approach, as seen in regulatory trials in Non-Alcoholic Steatohepatitis (NASH).

The effect of the magnitude of weight loss on non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Trials show that weight loss interventions improve biomarkers of non-alcoholic fatty liver disease (NAFLD), but it is unclear if a dose-response relationship exists.

OBJECTIVE

We aimed to quantify the dose-response relationship between the magnitude of weight loss and improvements in NAFLD.

METHODS

Nine databases and trial registries were searched until October 2020. Single-arm, non-randomized comparative, or randomized trials of weight loss interventions (behavioral weight loss programs [BWLPs], pharmacotherapy, or bariatric surgery) in people with NAFLD were eligible for inclusion if they reported an association between changes in weight and changes in blood, radiological, or histological biomarkers of liver disease. The review followed Cochrane methods and the risk of bias was assessed using the Newcastle-Ottawa scale. Pooled unstandardized b coefficients were calculated using random-effect meta-analyses.

RESULTS

Forty-three studies (BWMPs: 26, pharmacotherapy: 9, surgery: 8) with 2809 participants were included. The median follow-up was 6 (interquartile range: 6) months. The direction of effect was generally consistent but the estimates imprecise. Every 1 kg of weight lost was associated with a 0.83-unit (95% CI: 0.53 to 1.14, p < 0.0001, I² = 92%, n = 18) reduction in alanine aminotransferase (U/L), a 0.56-unit (95% CI: 0.32 to 0.79, p < 0.0001, I² = 68%, n = 11) reduction in aspartate transaminase (U/L), and a 0.77 percentage point (95% CI: 0.51 to 1.03, p < 0.0001, I² = 72%, n = 11) reduction in steatosis assessed by radiology or histology. There was evidence of a dose-response relationship with liver inflammation, ballooning, and resolution of NAFLD or NASH, but limited evidence of a dose-response relationship with fibrosis or NAFLD activity score. On average, the risk of bias for selection and outcome was medium and low, respectively.

CONCLUSION

Clinically significant improvements in NAFLD are achieved even with modest weight loss, but greater weight loss is associated with greater improvements. Embedding support for formal weight loss programs as part of the care pathway for the treatment of NAFLD could reduce the burden of disease.

PROSPERO

CRD42018093676.