Improved Diet Quality Associates With Reduction in Liver Fat, Particularly in Individuals With High Genetic Risk Scores for Nonalcoholic Fatty Liver Disease

Obesity and MASLD: Is weight loss the (only) key to treat metabolic liver disease?

Metabolic dysfunction-associated steatotic liver disease (MASLD) closely associates with obesity and type 2 diabetes. Lifestyle intervention and bariatric surgery aiming at substantial weight loss are cornerstones of MASLD treatment by improving histological outcomes and reducing risks of comorbidities. Originally developed as antihyperglycemic drugs, incretin (co-)agonists and SGLT2 inhibitors also reduce steatosis and cardiorenovascular events. Certain incretin agonists effectively improve histological features of MASLD, but not fibrosis. Of note, beneficial effects on MASLD may not necessarily require weight loss. Despite moderate weight gain, one PPARγ agonist improved adipose tissue and MASLD with certain benefit on fibrosis in post-hoc analyses. Likewise, the first THRβ-agonist was recently provisionally approved because of significant improvements of MASLD and fibrosis. We here discuss liver-related and metabolic effects induced by different MASLD treatments and their association with weight loss. Therefore, we compare results from clinical trials on drugs acting via weight loss (incretin (co)agonists, SGLT2 inhibitors) with those exerting no weight loss (pioglitazone; resmetirom). Furthermore, other drugs in development directly targeting hepatic lipid metabolism (lipogenesis inhibitors, FGF21 analogs) are addressed. Although THRβ-agonism may effectively improve hepatic outcomes, MASLD treatment concepts should consider all cardiometabolic risk factors for effective reduction of morbidity and mortality in the affected people.

Dietary patterns in the progression of metabolic dysfunction-associated fatty liver disease to advanced liver disease: a prospective cohort study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a significant health problem. Dietary intervention plays an important role in patients with MAFLD.

OBJECTIVE

We aimed to provide a reference for dietary patterns in patients with MAFLD.

METHODS

The presence of MAFLD was determined in the UK Biobank cohort. Nine dietary pattern scores were derived from the dietary records. Multivariable Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). The contrast test was employed to calculate the heterogeneity across MAFLD statuses.

RESULTS

We identified 175,300 patients with MAFLD at baseline. Compared with non-MAFLD, MAFLD was significantly associated with chronic liver disease (CLD) (HR: 3.48, 95% CI: 3.15-3.84), severe liver disease (SLD) (HR: 2.87, 95% CI: 2.63-3.14), liver cancer (HR: 1.93, 95% CI: 1.67-2.23), and liver-related death (LRD) (HR: 1.93, 95% CI: 1.67-2.23). In the overall cohort, the alternate Mediterranean diet (aMED) (HRCLD: 0.53, 95% CI: 0.37-0.76; HRSLD: 0.52, 95% CI: 0.37-0.72), Planetary Health Diet (PHD) (HRCLD: 0.62, 95% CI: 0.47-0.81; HRSLD: 0.65, 95% CI: 0.51-0.83) , plant based Low-carbohydrate Diet (pLCD) (HRCLD: 0.65, 95% CI: 0.49-0.86; HRSLD: 0.66, 95% CI: 0.51-0.85), and healthful Plant-based Diet Index (hPDI) (HRCLD: 0.63, 95% CI: 0.47-0.84; HRSLD: 0.61, 95% CI: 0.47-0.78) were associated with a lower risk of CLD and SLD. Additionally, unhealthful Plant-based Diet Index (uPDI) was associated with increased risk of CLD (HR: 1.42, 95% CI: 1.09-1.85), SLD (HR: 1.50, 95% CI: 1.19-1.90), and LRD (HR: 1.88, 95% CI: 1.28-2.78). The aforementioned associations remained consistently strong within the MAFLD subgroup, while exhibiting less pronounced in the non-MAFLD group. However, no significant heterogeneity was observed across different MAFLD statuses.

CONCLUSION

These findings highlight the detrimental effects of MAFLD on the development of subsequent liver diseases and the importance of dietary patterns in managing MAFLD.

Association Between Cardiovascular Health and Cirrhosis and Mortality: Insights From a Comprehensive Cross-sectional Study

GOAL

We aim to explore the relationship between the newly introduced CVH indicator "Life's Essential 8 (LE8)" and cirrhosis.

BACKGROUND

The global burden of cirrhosis is increasing, with a rising number of deaths, leading to significant societal and economic challenges. Cardiovascular health (CVH) has been found to have potential associations with liver diseases.

MATERIALS AND METHODS

All participants aged 20 and older from National Health and Nutrition Examination Survey 2005 to 2018 were included. CVH was accessed by LE8, consisting of 4 health behaviors (diet, physical activity, nicotine exposure, and sleep health) and 4 health factors (body mass index, lipid levels, blood sugar, and blood pressure). Cirrhosis was determined based on abnormal liver function test results, with an aspartate aminotransferase to platelet ratio index >2. Participants' mortality status was obtained by matching with the National Death Index and all-cause mortality served as the follow-up endpoint.

RESULTS

This extensive cross-sectional study reveals that LE8 was not associated with cirrhosis. A higher health behaviors score was associated with lower cirrhosis. Moreover, there is an inverse U-shaped relationship between the LE8 score and all-cause mortality in participants with cirrhosis, signifying a decrease in all-cause mortality when LE8 surpasses 60. A greater health behaviors score is linked to a decreased proportion of all-cause mortality in cirrhosis patients.

CONCLUSION

Maintaining better health behaviors may be beneficial for cirrhosis, especially through a balanced diet, regular exercise, smoking cessation, and quality sleep.

Dietary and genetic determinants of non-alcoholic fatty liver disease in coronary heart disease patients

PURPOSE

A healthy diet reduces the risk of non-alcoholic fatty liver disease (NAFLD) in the general population, especially in individuals who are genetically predisposed to NAFLD. Little is known in patients who suffered from a myocardial infarction (MI). We examined the interaction between diet quality and genetic predisposition in relation to NAFLD in post-MI patients.

METHODS

We included 3437 post-MI patients from the Alpha Omega Cohort. Diet quality was assessed with adherence to the Dutch Healthy Diet index 2015 (DHD15-index). A weighted genetic risk score (GRS) for NAFLD was computed using 39 genetic variants. NAFLD prevalence was predicted using the Fatty Liver Index. Prevalence ratios (PR) with 95% confidence intervals of DHD15-index and GRS in relation to NAFLD were obtained with multivariable Cox proportional hazards models. The interaction between DHD15-index and GRS in relation to NAFLD was assessed on an additive and multiplicative scale.

RESULTS

Patients had a mean age of 69 (± 5.5) years, 77% was male and 20% had diabetes. The DHD15-index ranged from 28 to 120 with a mean of 73. Patients with higher diet quality were less likely to suffer from NAFLD, with a PR of 0.76 (0.62, 0.92) for the upper vs lower quintile of DHD15-index. No association between the GRS and NAFLD prevalence was found (PR of 0.92 [0.76, 1.11]). No statistically significant interaction between the DHD15-index and GRS was observed.

CONCLUSION

In Dutch post-MI patients, adherence to the Dutch dietary guidelines was associated with a lower prevalence of NAFLD, as assessed by the FLI. This association was present regardless of genetic predisposition in this older aged cohort.

EASL-EASD-EASO Clinical Practice Guidelines on the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes, and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes (T2D) or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as FIB-4) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification - including weight loss, dietary changes, physical exercise and discouraging alcohol consumption - as well as optimal management of comorbidities - including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for T2D or obesity, if indicated - is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes, and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes (T2D) or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as FIB-4) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification - including weight loss, dietary changes, physical exercise and discouraging alcohol consumption - as well as optimal management of comorbidities - including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for T2D or obesity, if indicated - is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

Unraveling the intricate dance of the Mediterranean diet and gut microbiota in autoimmune resilience

The nutritional habits regulate the gut microbiota and increase risk of an autoimmune disease. Western diet is rich in sugars, meat, and poly-unsaturated fatty acids, which lead to dysbiosis of intestinal microbiota, disruption of gut epithelial barrier and chronic mucosal inflammation. In contrast, the Mediterranean Diet (MedDiet) is abundant in ω3 fatty acids, fruits, and vegetables, possessing anti-inflammatory properties that contribute to the restoration of gut eubiosis. Numerous studies have extensively examined the impact of MedDiet and its components on both health and various disease states. Additionally, specific investigations have explored the correlation between MedDiet, microbiota, and the risk of autoimmune diseases. Furthermore, the MedDiet has been linked to a reduced risk of cardiovascular diseases, playing a pivotal role in lowering mortality rates among individuals with autoimmune diseases and comorbidities. The aim of the present review is to specifically highlight current knowledge regarding possible interactions of MedDiet with the patterns of intestinal microbiota focusing on autoimmunity and a blueprint through dietary modulations for the prevention and management of disease's activity and progression.

Adipose tissue-derived metabolite risk scores and risk for type 2 diabetes in South Asians

BACKGROUND

South Asians are at higher risk for type 2 diabetes (T2D) than many other race/ethnic groups. Ectopic adiposity, specifically hepatic steatosis and visceral fat may partially explain this. Our objective was to derive metabolite risk scores for ectopic adiposity and assess associations with incident T2D in South Asians.

METHODS

We examined 550 participants in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) cohort study aged 40-84 years without known cardiovascular disease or T2D and with metabolomic data. Computed tomography scans at baseline assessed hepatic attenuation and visceral fat area, and fasting serum specimens at baseline and after 5 years assessed T2D. LC-MS-based untargeted metabolomic analysis was performed followed by targeted integration and reporting of known signals. Elastic net regularized linear regression analyses was used to derive risk scores for hepatic steatosis and visceral fat using weighted coefficients. Logistic regression models associated metabolite risk score and incident T2D, adjusting for age, gender, study site, BMI, physical activity, diet quality, energy intake and use of cholesterol-lowering medication.

RESULTS

Average age of participants was 55 years, 36% women with an average body mass index (BMI) of 25 kg/m2 and 6% prevalence of hepatic steatosis, with 47 cases of incident T2D at 5 years. There were 445 metabolites of known identity. Of these, 313 metabolites were included in the MET-Visc score and 267 in the MET-Liver score. In most fully adjusted models, MET-Liver (OR 2.04 [95% CI 1.38, 3.03]) and MET-Visc (OR 2.80 [1.75, 4.46]) were associated with higher odds of T2D. These associations remained significant after adjustment for measured adiposity.

CONCLUSIONS

Metabolite risk scores for intrahepatic fat and visceral fat were strongly related to incident T2D independent of measured adiposity. Use of these biomarkers to target risk stratification may help capture pre-clinical metabolic abnormalities.

Supplementation of Micro- and Macronutrients-A Role of Nutritional Status in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a condition in which the pathological cumulation of fat with coexisting inflammation and damage of hepatic cells leads to progressive dysfunctions of the liver. Except for the commonly well-known major causes of NAFLD such as obesity, dyslipidemia, insulin resistance, or diabetes, an unbalanced diet and imbalanced nutritional status should also be taken into consideration. In this narrative review, we summarized the current knowledge regarding the micro- and macronutrient status of patients suffering from NAFLD considering various diets and supplementation of chosen supplements. We aimed to summarize the knowledge indicating which nutritional impairments may be associated with the onset and progression of NAFLD at the same time evaluating the potential therapy targets that could facilitate the healing process. Except for the above-mentioned objectives, one of the most important aspects of this review was to highlight the possible strategies for taking care of NAFLD patients taking into account the challenges and opportunities associated with the micronutrient status of the patients. The current research indicates that a supplementation of chosen vitamins (e.g., vitamin A, B complex, C, or D) as well as chosen elements such as zinc may alleviate the symptoms of NAFLD. However, there is still a lack of sufficient data regarding healthy ranges of dosages; thus, further research is of high importance in this matter.

Genetic risk accentuates dietary effects on hepatic steatosis, inflammation and fibrosis in a population-based cohort

BACKGROUND & AIMS

Steatotic liver disease (SLD), characterized by elevated liver fat content (LFC), is influenced by genetics and diet. However, whether diet has a differential effect based on genetic risk is not well-characterized. We aimed to determine how genetic factors interact with diet to affect SLD in a large national biobank.

METHODS

We included UK Biobank participants with dietary intake measured by 24-hour recall and genotyping. The primary predictors were dietary pattern, PNPLA3-rs738409-G, TM6SF2-rs58542926-T, a 16-variant hepatic steatosis polygenic risk score (PRS), and gene-environment interactions. The primary outcome was LFC, and secondary outcomes were iron-controlled T1 time (cT1, a measure of liver inflammation and fibrosis) and liver-related events/mortality.

RESULTS

A total of 21,619 participants met inclusion criteria. In non-interaction models, Mediterranean diet and intake of fruit/vegetables/legumes and fish associated with lower LFC, while higher red/processed meat intake and all genetic predictors associated with higher LFC. In interaction models, all genetic predictors interacted with Mediterranean diet and fruit/vegetable/legume intake, while the steatosis PRS interacted with fish intake and the TM6SF2 genotype interacted with red/processed meat intake, to affect LFC. Dietary effects on LFC were up to 3.8-fold higher in PNPLA3-rs738409-GG vs. -CC individuals, and 1.4-3.0-fold higher in the top vs. bottom quartile of the steatosis PRS. Gene-diet interactions were stronger in participants with vs. without overweight. The steatosis PRS interacted with Mediterranean diet and fruit/vegetable/legume intake to affect cT1 and most dietary and genetic predictors associated with risk of liver-related events or mortality by age 70.

CONCLUSIONS

Effects of diet on LFC and cT1 were markedly accentuated in patients at increased genetic risk for SLD, implying dietary interventions may be more impactful in these populations.

IMPACT AND IMPLICATIONS

Genetic variants and diet both influence risk of hepatic steatosis, inflammation/fibrosis, and hepatic decompensation; however, how gene-diet interactions influence these outcomes has previously not been comprehensively characterized. We investigated this topic in the community-based UK Biobank and found that genetic risk and dietary quality interacted to influence hepatic steatosis and inflammation/fibrosis on liver MRI, so that the effects of diet were greater in people at elevated genetic risk. These results are relevant for patients and medical providers because they show that genetic risk is not fixed (i.e. modifiable factors can mitigate or exacerbate this risk) and realistic dietary changes may result in meaningful improvement in liver steatosis and inflammation/fibrosis. As genotyping becomes more routinely used in clinical practice, patients identified to be at high baseline genetic risk may benefit even more from intensive dietary counseling than those at lower risk, though future prospective studies are required.

Bariatric Nutritional Intervention in Obese Patients with Compensated Liver Cirrhosis: A Four-Year Prospective Study

BACKGROUND

Obesity and liver cirrhosis represent significant health challenges, often leading to various complications.

AIMS

This prospective study aimed to investigate the impact of a four-year bariatric intervention, focusing on adherence to the Mediterranean Diet, on anthropometric, hematologic, and biochemical parameters in obese patients with compensated liver cirrhosis. Additionally, the study evaluated the concurrent contribution of weight loss to these health indicators.

METHODS

The study involved 62 patients with compensated liver cirrhosis (mean age 65.87 ± 6 years) and 44 healthy controls (mean age 59.11 ± 8 years), all with a BMI > 30 kg/m2. Both groups underwent a weight loss intervention based on the Mediterranean diet, with a four-year follow-up. Anthropometric, biochemical and hematologic parameters were evaluated at several time points during the study and their statistical significance was assessed.

RESULTS

Anthropometric parameters, including weight, BMI, waist and hip circumference, percentage of fat mass, and handgrip strength, exhibited significant improvements (p < 0.05), particularly within the first year of the intervention. Liver function tests and lipid profiles of the patients also showed significant enhancements (p < 0.05). Hematological and biochemical indices, such as hematocrit and ferritin, experienced discreet improvements in the patient cohort (p < 0.05).

CONCLUSIONS

This study highlights the potential of a structured bariatric intervention rooted in the Mediterranean diet to positively influence the health of obese patients with compensated liver cirrhosis. The observed improvements in anthropometric, biochemical, and hematologic parameters, particularly within the first year of the intervention, suggest the importance of dietary modifications in managing the health of this patient population.

Dietary inflammatory index is associated with metabolic dysfunction-associated fatty liver disease among United States adults

Background

Metabolic dysfunction-associated fatty liver disease (MAFLD) is presently the most prevalent chronic liver disorder globally that is closely linked to obesity, dyslipidemia metabolic syndrome, and type 2 diabetes mellitus (T2DM). Its pathogenesis is strongly associated with inflammation, and diet is a major factor in reducing inflammation. However, current research has focused primarily on exploring the relationship between diet and NAFLD, with less research on its link to MAFLD.

Methods

In this research, using dietary inflammatory index (DII) as a measure to assess dietary quality, we analyzed the relationship between diet and MAFLD. Data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018, including 3,633 adults with complete DII and MAFLD, were used to develop cross-sectional analyses. Logistic regression analysis was adapted for investigating the relationship between DII and MAFLD development. Additionally, subgroup analysis and threshold effect analysis were carried out.

Results

A positive link between DII and MAFLD was found in the fully adjusted model (OR = 1.05; 95%CI, 1.00-1.11, p < 0.05). Subgroup analysis indicated that there was no significant dependence for the connection between DII and MAFLD except for the subgroup stratified by age. Compared with other age groups, people with MAFLD had 20% higher DII scores than non-MAFLD participants in those aged 20-41 years old (OR = 1.20; 95%CI, 1.08-1.33, p < 0.001). Furthermore, we found a U-shaped curve with an inflection point of 3.06 illustrating the non-linear connection between DII and MAFLD.

Conclusion

As a result, our research indicates that pro-inflammatory diet may increase the chance of MAFLD development, thus improved dietary patterns as a lifestyle intervention is an important strategy to decrease the incidence of MAFLD.

Association of five diet scores with severe NAFLD incidence: A prospective study from UK Biobank

AIM

This study aimed to contrast the associations of five common diet scores with severe non-alcoholic fatty liver disease (NAFLD) incidence.

MATERIALS AND METHODS

In total, 162 999 UK Biobank participants were included in this prospective population-based study. Five international diet scores were included: the 14-Item Mediterranean Diet Adherence Screener (MEDAS-14), the Recommended Food Score (RFS), the Healthy Diet Indicator (HDI), the Mediterranean Diet Score and the Mediterranean-DASH Intervention for Neurodegenerative Delay score. As each score has different measurements and scales, all scores were standardized and categorized into quartiles. Cox proportional hazard models adjusted for confounder factors investigated associations between the standardized quartiles and severe NAFLD incidence.

RESULTS

Over a median follow-up of 10.2 years, 1370 participants were diagnosed with severe NAFLD. When the analyses were fully adjusted, participants in quartile 4 using the MEDAS-14 and RFS scores, as well as those in quartiles 2 and 3 using the HDI score, had a significantly lower risk of severe incident NAFLD compared with those in quartile 1. The lowest risk was observed in quartile 4 for the MEDAS-14 score [hazard ratio (HR): 0.76 (95% confidence interval (CI): 0.62-0.94)] and the RFS score [HR: 0.82 (95% CI: 0.69-0.96)] and as well as in quartile 2 in the HDI score [HR: 0.80 (95% CI: 0.70-0.91)].

CONCLUSION

MEDAS-14, RFS and HDI scores were the strongest diet score predictors of severe NAFLD. A healthy diet might protect against NAFLD development irrespective of the specific approach used to assess diet. However, following these score recommendations could represent optimal dietary approaches to mitigate NAFLD risk.

Practical Lifestyle Management of Nonalcoholic Fatty Liver Disease for Busy Clinicians

Weight loss achieved through a combination of healthy eating patterns that encompass the principles of the Mediterranean diet and regular physical activity is the most evidence-based treatment for nonalcoholic fatty liver disease. Although other types of diets have demonstrated efficacy in liver fat reduction, the Mediterranean diet confers additional cardiometabolic benefits. Macronutrient composition, food choices, and timing of eating can be tailored to individual preferences, culture, and financial circumstances; however, recommended healthy eating patterns are characterized by minimally processed or unprocessed foods (vegetables, legumes, nuts and seeds, fruits, whole grains, and unprocessed meats and fish) that are low in sugar, refined carbohydrates, and saturated fat and high in fiber, polyphenols, vitamins, minerals, and healthy fats. Physical activity can independently improve steatosis, prevent fibrosis and cirrhosis, and reduce mortality.

Mobile App-Based Lifestyle Coaching Intervention for Patients With Nonalcoholic Fatty Liver Disease: Randomized Controlled Trial

BACKGROUND

Lifestyle modification in patients with nonalcoholic fatty liver disease (NAFLD) is key to improving health outcomes. Mobile health technologies may offer potential effective and efficient health care support to facilitate self-management.

OBJECTIVE

This study aims to develop a lifestyle coaching intervention using a mobile app for patients with NAFLD and evaluate physiological and psychological health outcomes for 6 months.

METHODS

This study was a randomized controlled trial. The personalized lifestyle coaching intervention using a mobile app was developed through established guidelines and literature reviews. This intervention consisted of information on NAFLD management, diet and physical activity self-monitoring, and coaching sessions based on patient records and SMS text messages. A total of 102 individuals were enrolled in the study and randomly assigned to the intervention group (n=48) or the control group (n=54). The outcomes were improvements in physiological (weight, liver fat score, aspartate aminotransferase, alanine transferase, and gamma-glutamyl transferase) and clinical outcomes (self-management, NAFLD self-management knowledge, self-efficacy, fatigue, depression, and quality of life). Data were analyzed using descriptive analysis and a linear mixed model to test the effects of the intervention.

RESULTS

All participants completed the study. The mean age of the participants was 48.9 (SD 13.74) years, 38.2% (39/102) were female participants, and 65.7% (67/102) were married. There were no differences in baseline demographic and clinical data between the intervention and control groups. Changes from baseline to 6 months were significant only within the intervention group for weight (P<.001), liver fat score (P=.01), aspartate aminotransferase (P=.03), alanine transferase (P=.002), gamma-glutamyl transferase (P=.04), self-management (P<.001), fatigue (P=.005), depression (P=.003), and quality of life (P<.001). The differences between the 2 groups for the changes over the 6 months were significant in self-management (P=.004), self-management knowledge (P=.04), fatigue (P=.004), depression (P=.04), and quality of life (P=.01). However, the intervention-by-time interaction was significantly effective only for self-management (P=.006) and fatigue (P=.02).

CONCLUSIONS

Nonpharmacological interventions using a mobile app may be effective in improving the physiological and psychological health outcomes of patients with NAFLD.

TRIAL REGISTRATION

Clinical Research Information Service KCT0005549; http://tinyurl.com/y2zb6usy.

The sulfur microbial diet and risk of nonalcoholic fatty liver disease: a prospective gene-diet study from the UK Biobank

BACKGROUND

The gut microbiota is closely related to liver diseases. The dietary pattern associated with sulfur-metabolizing bacteria in stool has been found to influence intestinal health.

OBJECTIVE

We aimed to investigate whether consuming the sulfur microbial diet is associated with nonalcoholic fatty liver disease (NAFLD).

METHODS

We included 143,918 participants of European descent from the UK Biobank. Information on serving sizes used per diet component was recorded by an online 24-h dietary assessment tool (Oxford WebQ). The total sulfur microbial diet score was constructed by summing the product of β-coefficients and corresponding serving sizes. NAFLD was ascertained using hospital inpatient and death records. Cox proportional hazard models were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI). Mediation analyses were used to investigate underlying mediators including body mass index, waist circumference, glucose, triglyceride, urate, and C-reactive protein. A polygenic risk score for NAFLD was constructed and stratified to assess whether the association is modified by genetic predisposition.

RESULTS

After a median follow-up of 11.7 y (interquartile range: 11.3-12.5 y), we documented 1540 incident cases of NAFLD. After adjustment for covariates, we observed an overall J-shaped relationship between the sulfur microbial diet and risk of NAFLD. Those in the highest quartile of sulfur microbial diet score had a 46% increased risk of NAFLD [HRQ4vsQ1 (95% CI): 1.46 (1.26, 1.69)]. We also found that this association is partly mediated by metabolic disorders and systemic inflammation. In addition, the positive association was stronger among individuals at higher genetic risk for NAFLD (Pinteraction = 0.044).

CONCLUSIONS

The sulfur microbial diet had adverse associations with incident NAFLD, particularly in those at a higher genetic risk. Our study may provide evidence on the role of sulfur-metabolizing bacteria in the diet-NAFLD association.

Modifiable lifestyle factors, genetic and acquired risk, and the risk of severe liver disease in the UK Biobank cohort: (Lifestyle factors and SLD)

BACKGROUND

Lifestyle intervention is important for the treatment of liver diseases.

AIMS

To clarify the association of healthy lifestyle with severe liver disease (SLD) and assessed whether genetic susceptibility and acquired fibrosis risk can modify the association.

METHODS

We included 417,986 UK Biobank participants who were free of SLD at baseline. Information on seven modifiable lifestyle factors was collected through a baseline questionnaire. SLD was defined as a medical diagnosis of cirrhosis, hepatocellular carcinoma or liver failure. Cox proportional hazards models were used to evaluate the association between healthy lifestyle factors and risk of incident SLD. The polygenic risk score (PRS) and fibrosis-4 index (FIB-4) were calculated and set as an interaction term.

RESULTS

During a median follow-up of 12.6 years, 4542 fatal and non-fatal SLD incidents were identified. A higher overall lifestyle score was associated with a significantly lower SLD risk (Ptrend <0.001). An increment of 1-point lifestyle score combined with a 1-SD increment in FIB-4 or PRS was associated with an additional reduction of 3% or 2% in SLD risk.

CONCLUSIONS

In European individuals, a healthy lifestyle is associated with a lower risk of incident SLD, which is more pronounced among individuals with a higher genetic and fibrosis risk.

Exploring a novel therapeutic strategy: the interplay between gut microbiota and high-fat diet in the pathogenesis of metabolic disorders

In the past two decades, the rapid increase in the incidence of metabolic diseases, including obesity, diabetes, dyslipidemia, non-alcoholic fatty liver disease, hypertension, and hyperuricemia, has been attributed to high-fat diets (HFD) and decreased physical activity levels. Although the phenotypes and pathologies of these metabolic diseases vary, patients with these diseases exhibit disease-specific alterations in the composition and function of their gut microbiota. Studies in germ-free mice have shown that both HFD and gut microbiota can promote the development of metabolic diseases, and HFD can disrupt the balance of gut microbiota. Therefore, investigating the interaction between gut microbiota and HFD in the pathogenesis of metabolic diseases is crucial for identifying novel therapeutic strategies for these diseases. This review takes HFD as the starting point, providing a detailed analysis of the pivotal role of HFD in the development of metabolic disorders. It comprehensively elucidates the impact of HFD on the balance of intestinal microbiota, analyzes the mechanisms underlying gut microbiota dysbiosis leading to metabolic disruptions, and explores the associated genetic factors. Finally, the potential of targeting the gut microbiota as a means to address metabolic disturbances induced by HFD is discussed. In summary, this review offers theoretical support and proposes new research avenues for investigating the role of nutrition-related factors in the pathogenesis of metabolic disorders in the organism.

Adherence to a Traditional Mexican Diet Is Associated with Lower Hepatic Steatosis in US-Born Hispanics of Mexican Descent with Overweight or Obesity

Hispanics of Mexican descent have disproportionate rates of non-alcoholic fatty liver disease (NAFLD). The purpose of this work is to investigate the association between the traditional Mexican diet score (tMexS) and hepatic steatosis and fibrosis, two NAFLD-related clinical endpoints, in Hispanic adults of Mexican descent. Data from 280 Hispanic adults of Mexican descent (n = 102 men, 178 women) with overweight or obesity enrolled in a cross-sectional observational study were analyzed. The tMexS was calculated from 24 h dietary recalls. Hepatic steatosis and fibrosis measurements were assessed using transient elastography (Fibroscan®). Linear regression models testing the association between tMexS and hepatic steatosis and fibrosis were run individually and through the stratification of significant modifiers. Mean tMexS were 5.9 ± 2.1, hepatic steatosis scores were 288.9 ± 48.9 dB/m, and fibrosis scores were 5.6 ± 2.2 kPa. Among the US-born group, with every point increase in the tMexS, there was a statistically significant 5.7 lower hepatic steatosis point (95% CI: -10.9, -0.6, p-value = 0.07). Higher adherence to a traditional Mexican diet was associated with lower hepatic steatosis in US-born Hispanics of Mexican descent. Findings from the current work may serve to inform future culturally relevant interventions for NAFLD prevention and management in individuals of Mexican descent.

Association of healthy dietary patterns and cardiorespiratory fitness in the community

AIMS

To evaluate the associations of dietary indices and quantitative cardiorespiratory fitness (CRF) measures in a large, community-based sample harnessing metabolomic profiling to interrogate shared biology.

METHODS AND RESULTS

Framingham Heart Study (FHS) participants underwent maximum effort cardiopulmonary exercise tests for CRF quantification (via peak VO2) and completed semi-quantitative food frequency questionnaires. Dietary quality was assessed by the Alternative Healthy Eating Index (AHEI) and Mediterranean-style Diet Score (MDS), and fasting blood concentrations of 201 metabolites were quantified. In 2380 FHS participants (54 ± 9 years, 54% female, body mass index 28 ± 5 kg/m2), 1 SD higher AHEI and MDS were associated with 5.2% (1.2 mL/kg/min, 95% CI 4.3-6.0%, P < 0.0001) and 4.5% (1.0 mL/kg/min, 95% CI 3.6-5.3%, P < 0.0001) greater peak VO2 in linear models adjusted for age, sex, total daily energy intake, cardiovascular risk factors, and physical activity. In participants with metabolite profiling (N = 1154), 24 metabolites were concordantly associated with both dietary indices and peak VO2 in multivariable-adjusted linear models (FDR < 5%). Metabolites that were associated with lower CRF and poorer dietary quality included C6 and C7 carnitines, C16:0 ceramide, and dimethylguanidino valeric acid, and metabolites that were positively associated with higher CRF and favourable dietary quality included C38:7 phosphatidylcholine plasmalogen and C38:7 and C40:7 phosphatidylethanolamine plasmalogens.

CONCLUSION

Higher diet quality is associated with greater CRF cross-sectionally in a middle-aged community-dwelling sample, and metabolites highlight potential shared favourable effects on cardiometabolic health.

The quality and reliability of TikTok videos on non-alcoholic fatty liver disease: a propensity score matching analysis

Background

Lifestyle modification is the cornerstone of non-alcoholic fatty liver disease (NAFLD) prevention and treatment. Short video platforms can facilitate easier access to health information for patients, thereby influencing lifestyle changes. An increasing number of individuals rely on online platforms to acquire health-related information about NAFLD. However, the quality of information regarding NAFLD on these platforms remains unclear.

Objective

This study aimed to investigate the quality of information about NAFLD on TikTok.

Methods

A total of 497 videos were retrieved from TikTok. The basic video information, including the video source, was extracted. Two independent raters evaluated the quality and reliability of the videos using the Global Quality Score system and a modified DISCERN tool. Propensity score matching (PSM) was used to compare video quality across sources.

Results

NAFLD-related videos on TikTok were divided into three groups according to the uploader: health professionals, medical institutions, and science bloggers. Overall, the quality of NAFLD videos on TikTok was not satisfactory. Before PSM, there were no significant differences in video quality or content between the three groups. After PSM, the quality of NAFLD videos from health professionals was significantly better than the videos created by other groups. Besides, the videos of health professionals outperformed those of medical institutions and science bloggers in terms of the definition of disease, risk factors, and treatment, but were inferior to those of medical institutions considering the symptoms and tests of NAFLD.

Conclusion

The quality of NAFLD-related videos on TikTok needs improvement. Compared with videos created by science bloggers and medical institutions, videos from health professionals may provide accurate guidance on the treatment and prevention of NAFLD.

Relationship between diet quality and nonalcoholic fatty liver disease predictor indices in Iranian patients with metabolic syndrome: A cross-sectional study

The present study aimed to assess the association between diet quality and nonalcoholic fatty liver disease (NAFLD) predictor indices in patients with metabolic syndrome (MetS). This cross-sectional study was carried out among 344 adult patients with MetS. The diet quality of patients was calculated by Healthy Eating Index-2015 (HEI-2015). NAFLD predictor indices (Hepatic Steatosis Index [HSI], Triglyceride-Glucose Index [TyG], and Fatty Liver Index [FLI]) were calculated and compared according to the HEI-2015 quartiles. The relationship between the HEI-2015 score and HSI, FLI, and TyG Index was estimated using multiple linear regression analysis. The findings of the present study revealed that patients with the highest HEI score had the lowest FLI score (p = .003) and HSI score (p = .05). There was an inverse relationship between the HEI-2015 score and FLI (β = -0.49; p < .001), HSI (β = -0.05; p = .25), and TyG Index (β = -0.002; p = .34). According to our result, after adjusting for possible confounding factors, there was a statistically significant inverse association between HEI-2015 and FLI.

Plant-based diets, genetic predisposition and risk of non-alcoholic fatty liver disease

BACKGROUND

Diets rich in plant-based foods are associated with lower risks of non-alcoholic fatty liver disease (NAFLD), while the prospective evidence is limited. We aimed to examine longitudinal associations of plant-based diets and genetic susceptibility with NAFLD risk.

METHODS

This longitudinal cohort study included 159,222 participants (58.0 ± 8.0 years old, 55.7% female) free of NAFLD in the UK Biobank. We calculated the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI). New-onset NAFLD was the primary outcome. The weighted polygenic risk score was calculated based on risk variants associated with NAFLD. Hazard ratios (HR) and 95% confidential intervals (CI) were estimated by Cox proportional hazards model. Magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) measured liver fat content in a subsample of 20,692 participants (57.5 ± 7.4 years old, 52.6% female) was the secondary outcome. The associations between plant-based diet indices and MRI-PDFF were evaluated using generalized linear models.

RESULTS

During a median follow-up of 9.5 years, 1541 new-onset NAFLD cases were documented. Compared to the lowest quintile, multivariable-adjusted hazard ratios (HRs) of NAFLD in the highest quintile were 0.78 (95% confidential intervals [CI], 0.66-0.93, p-trend =0.02), 0.74 (95% CI, 0.62-0.87, p-trend <0.0001), and 1.24 (95% CI, 1.05-1.46, p-trend = 0.02) for overall PDI, hPDI, and uPDI, respectively. For liver fat content, higher overall PDI and hPDI were associated with lower MRI-PDFF, while higher uPDI was associated with higher liver fat content. We observed a significant interaction between hPDI and PRS (p-interaction =0.03), and the NAFLD risk was lowest among participants with the highest hPDI and low genetic risk.

CONCLUSIONS

Higher intake of plant-based diets especially healthful plant-based diets was associated with lower NAFLD risk and liver fat content regardless of genetic susceptibility, whereas an unhealthful plant-based diet was associated with higher NAFLD risk and intrahepatic steatosis. These results suggest that the quality of plant-based foods should be highlighted when adopting a plant-based diet.

Dietary strategies in non-alcoholic fatty liver disease patients: From evidence to daily clinical practice, a systematic review

Lifestyle modification comprising calorie restriction (CR) and increased physical activity enabling weight loss is the first-line of treatment for non-alcoholic fatty liver disease (NAFLD). However, CR alone is not optimal and evidence suggests that dietary pattern and composition are also critical in NAFLD management. Accordingly, high consumption of red and processed meat, saturated fat, added sugar, and sweetened beverages are associated with an increased risk of developing NAFLD and hepatocellular carcinoma, while other foods and compounds such as fish, olive oil, and polyphenols are, in contrast, beneficial for metabolic disorders. Therefore, several dietary interventions have been studied in order to determine which strategy would be the most beneficial for NAFLD. The evidence regarding the effectiveness of different dietary interventions such as low carbohydrate/low-fat diet, time-restricted eating diet, CR, and the well-studied Mediterranean diet is summarized.

PEMT rs7946 Polymorphism and Sex Modify the Effect of Adequate Dietary Choline Intake on the Risk of Hepatic Steatosis in Older Patients with Metabolic Disorders

In humans, PEMT rs7946 polymorphism exerts sex-specific effects on choline requirement and hepatic steatosis (HS) risk. Few studies have explored the interaction effect of the PEMT rs7946 polymorphism and sex on the effect of adequate choline intake on HS risk. In this cross-sectional study, we investigated the association between PEMT polymorphism and adequate choline intake on HS risk. We enrolled 250 older patients with metabolic disorders with (n = 152) or without (n = 98; control) ultrasonically diagnosed HS. An elevated PEMT rs7946 A allele level was associated with a lower HS risk and body mass index in both men and women. Dietary choline intake-assessed using a semiquantitative food frequency questionnaire-was associated with reduced obesity in men only (p for trend < 0.05). ROC curve analysis revealed that the cutoff value of energy-adjusted choline intake for HS diagnosis was 448 mg/day in women (AUC: 0.62; 95% CI: 0.57-0.77) and 424 mg/day in men (AUC: 0.63, 95% CI: 0.57-0.76). In women, GG genotype and high choline intake (>448 mg/day) were associated with a 79% reduction in HS risk (adjusted OR: 0.21; 95% CI: 0.05-0.82); notably, GA or AA genotype was associated with a reduced HS risk regardless of choline intake (p < 0.05). In men, GG genotype and high choline intake (>424 mg/day) were associated with a 3.7-fold increase in HS risk (OR: 3.7; 95% CI: 1.19-11.9). Further adjustments for a high-density lipoprotein level and body mass index mitigated the effect of choline intake on HS risk. Current dietary choline intake may be inadequate for minimizing HS risk in postmenopausal Taiwanese women carrying the PEMT rs7946 GG genotype. Older men consuming more than the recommended amount of choline may have an increased risk of nonalcoholic fatty liver disease; this risk is mediated by a high-density lipoprotein level and obesity.

Association of Diet Quality with Metabolic (Dysfunction) Associated Fatty Liver Disease in Veterans in Primary Care

BACKGROUND

Diet is associated with metabolic (dysfunction)-associated fatty liver disease (MAFLD), but the dietary composition associated with MAFLD risk has not been well-examined.

AIM

The purpose of this study was to assess the association of two healthy eating indices with the presence and severity of MAFLD in a sample of Veterans in a primary care setting.

METHODS

This was a single center cross-sectional study using a random stratified sample of Veterans enrolled in primary care. Participants underwent a Fibroscan and completed an interviewer-administered Diet History Questionnaire II from which we calculated the Healthy Eating Index-2015 and Alternate Mediterranean Diet Score. We used multivariable logistic regression models to assess associations of dietary quality with MAFLD.

RESULTS

We analyzed data from 187 participants, 53.5% of whom were female. On average, participants were 50.2 years of age (SD, 12.3 years) with an average BMI of 31.7 kg/m2. MAFLD was detected in 78 (42%) and at least moderate fibrosis in 12 (6%) participants. We found that the Alternate Mediterranean Diet Score was inversely associated with MAFLD (adjusted OR = 0.85, 95%CI 0.72-1.00), but controlling for BMI and total energy intake attenuated the association (adjusted OR = 0.92, 95%CI 0.74-1.15). We found no statistically significant associations between the Healthy Eating Index-2015 and MAFLD or advanced fibrosis.

DISCUSSION

We found that the Alternate Mediterranean Diet Score was significantly associated with lower MAFLD risk in Veterans; however, the association was mediated by BMI and total energy intake. A Mediterranean-style diet could potentially help reduce the risk of MAFLD, particularly if it helps control total energy intake and weight.

The association of healthy lifestyle score and risk of non-alcoholic fatty liver disease

BACKGROUND

The combined role of important environmental factors as a single lifestyle index in predicting non-alcoholic fatty liver disease (NAFLD) risk is not fully assessed. Therefore, we aimed to investigate the association of healthy lifestyle factor score (HLS) with the odds of NAFLD in Iranian adults.

METHODS

This case-control study was conducted on 675 participants, aged ≥ 20-60 years, including 225 new NAFLD cases and 450 controls. We measured dietary intake information using a validated food frequency questionnaire and determined diet quality based on the alternate healthy eating index-2010(AHEI-2010). The score of HLS was calculated based on four lifestyle factors, including a healthy diet, normal body weight, non-smoking, and high physical activity. An ultrasound scan of the liver was used to detect NAFLD in participants of the case group. Logistic regression models were used to determine the odds ratios(ORs) and 95% confidence interval(CI) of NAFLD across tertiles of HLS and AHEI.

RESULTS

Mean ± SD age of the participants were 38.13 ± 8.85 years. The Mean ± SD HLS in the case and control groups was 1.55 ± 0.67 and 2.53 ± 0.87, respectively. Also, the Mean ± SD AHEI in the case and control groups was 48.8 ± 7.7 and 54.1 ± 8.1, respectively. Based on the age and sex-adjusted model, the odds of NAFLD were decreased across tertiles of AHEI (OR:0.18;95%CI:0.16-0.29,P_trend<0.001) and HLS(OR:0.03;95%CI:0.01-0.05,P_trend<0.001). Also, in the multivariable model, the odds of NAFLD were decreased across tertiles AHEI (OR:0.12;95%CI:0.06-0.24,P_trend<0.001) and HLS(OR:0.02;95%CI:0.01-0.04,P_trend<0.001).

CONCLUSIONS

Our findings reported that higher adherence to lifestyle with a higher score of HLS was associated with decreased odds of NAFLD. Also, a diet with a high AHEI score can reduce the risk of NAFLD in the adult population.

Fatty liver index relationship with biomarkers and lifestyle: result from RaNCD cohort study

BACKGROUND

Lifestyle intervention can effectively treat patients with non-alcoholic fatty liver disease (NAFLD). The present study aimed to investigate the association between lifestyle factors with fatty liver index (FLI) in Iranian adults.

METHODS

This study enrolled 7114 subjects from the Ravansar Non-Communicable Diseases (RaNCD) cohort study in western Iran. To compute the FLI score, anthropometric measures, and a few non-invasive liver status indicators were used. Binary logistic regression models examined the association between FLI score and lifestyle.

RESULTS

Participants with FLI < 60 had a lower daily energy intake compared to those with FLI ≥ 60 (2740.29 vs. 2840.33 kcal/day, P = < 0.001). The risk of NAFLD in males with high socioeconomic status (SES) was 72% higher than in those with low SES (OR: 1.72; 95% CIs 1.42-2.08). An adjusted logistic regression model showed a significantly negative association between high physical activity and fatty liver index in both men and women. (OR: 0.44, p-value < 0.001 and OR: 0.54, p-value < 0.001, respectively). The odds of NAFLD in female participants with depression were 71% higher than in non-depressed participants (OR: 1.71, 95% CI: 1.06-2.64). Dyslipidemia and high visceral fat area (VFA) were also associated with a significant increase in the risk of NAFLD (P < 0.05).

CONCLUSION

In our study, we found that good SES, high VFA, and dyslipidemia were associated with an increased risk of NAFLD. Conversely, high physical activity reduces the risk of NAFLD. Therefore, lifestyle modification may help improve liver function.

A Healthy Diet is Associated with a Lower Risk of Hepatic Fibrosis

BACKGROUND

Higher diet quality is associated with a lower risk of NAFLD.

OBJECTIVES

We examined the relationship between diet quality and hepatic fibrosis.

METHODS

We analyzed cross-sectional associations between 3 a priori diet quality scores-the Dietary Approaches to Stop Hypertension (DASH) score, the Alternative Healthy Eating Index (AHEI), and a modified Mediterranean-style Diet Score (MDS)-and hepatic fat [controlled attenuation parameter (CAP)] and fibrosis [liver stiffness measurement (LSM)] measured by vibration-controlled transient elastography (VCTE) in 2532 Framingham Heart Study (FHS) participants and 3295 participants of the National Health and Nutrition Examination Survey (NHANES).

RESULTS

Higher diet quality scores were associated with lower LSM in both FHS and NHANES after adjustment for demographic and lifestyle factors. Additional adjustment for CAP or BMI attenuated the observed associations. Association strength was similar across all 3 diet quality scores. Fixed-effect meta-analysis demonstrated that, under CAP-adjusted models, the LSM decreases associated with 1-SD increase of the DASH, AHEI, and MDS scores were 2% (95% CI: 0.7%, 3.3%; P = 0.002), 2% (95% CI: 0.7%, 3.3%; P = 0.003), and 1.7% (95% CI: 0.7%, 2.6%; P = 0.001), respectively, whereas in the meta-analysis of BMI-adjusted models, LSM reductions associated with 1-SD increase of the DASH, AHEI, and MDS scores were 2.2% (95% CI: -0.1%, 2.2%; P = 0.07), 1.5% (95% CI: 0.3%, 2.7%; P = 0.02), and 0.9 (95% CI: -0.1%, 1.9%; P = 0.07), respectively.

CONCLUSIONS

We demonstrated associations of higher diet quality with favorable hepatic fat and fibrosis measures. Our data suggest that a healthy diet may reduce the likelihood of obesity and hepatic steatosis as well as the progression of steatosis to fibrosis.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.

Current, emerging, and potential therapies for non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) has been identified as the most common chronic liver disease worldwide, with a growing incidence. NAFLD is considered the hepatic manifestation of a metabolic syndrome that emerges from multiple factors (e.g., oxidative stress, metabolic disorders, endoplasmic reticulum stress, cell death, and inflammation). Non-alcoholic steatohepatitis (NASH), an advanced form of NAFLD, has been reported to be a leading cause of cirrhosis and hepatic carcinoma, and it is progressing rapidly. Since there is no approved pharmacotherapy for NASH, a considerable number of therapeutic targets have emerged with the deepening of the research on NASH pathogenesis. In this study, the therapeutic potential and properties of regulating metabolism, the gut microbiome, antioxidant, microRNA, inhibiting apoptosis, targeting ferroptosis, and stem cell-based therapy in NASH are reviewed and evaluated. Since the single-drug treatment of NASH is affected by individual heterogeneous responses and side effects, it is imperative to precisely carry out targeted therapy with low toxicity. Lastly, targeted therapeutic agent delivery based on exosomes is proposed in this study, such that drugs with different mechanisms can be incorporated to generate high-efficiency and low-toxicity individualized medicine.

Protein foods from animal sources and risk of nonalcoholic fatty liver disease in representative cohorts from North and South China

BACKGROUND

Emerging evidence suggests that animal protein foods may increase the risk of nonalcoholic fatty liver disease (NAFLD). We therefore examined the NAFLD risk reduction related to substituting plant protein foods for animal protein foods.

METHODS

The cohort in North China included 14,541 participants from the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) study, and the cohort in South China included 1297 participants from the Guangzhou Nutrition and Health Study (GNHS). Dietary intake was assessed using validated food frequency questionnaires. NAFLD was ascertained by abdominal ultrasound. The Cox model was used to fit the substitution analysis.

RESULTS

In the TCLSIH cohort, when replacing one type of animal protein food (eggs, processed meat, unprocessed red meat, poultry, and fish) with an equivalent serving of plant protein foods (nuts, legumes, and whole grains), the replacement of animal protein foods with whole grains showed the strongest benefit; substituting one serving per day of whole grains for an equal amount of eggs (hazard ratio [HR] = 0.89; 95% confidence interval [CI]: 0.79, 1.00), processed meat (HR = 0.76; 95% CI: 0.64, 0.91), unprocessed red meat (HR = 0.90; 95% CI: 0.81, 1.00), poultry (HR = 0.81; 95% CI: 0.72, 0.92), or fish (HR = 0.87; 95% CI: 0.78, 0.97) was associated with a lower risk of NAFLD. In both the TCLSIH and GNHS cohorts, replacing poultry with fish, nuts, legumes, or whole grains was associated with a lower risk of NAFLD. When different numbers of protein foods were simultaneously replaced, the risk reduction of NAFLD was stronger.

CONCLUSIONS

Our findings suggest that replacing animal protein foods with plant protein foods is related to a significant reduction in NAFLD risk.

Nutraceutical approaches to non-alcoholic fatty liver disease (NAFLD): A position paper from the International Lipid Expert Panel (ILEP)

Non-Alcoholic Fatty Liver Disease (NAFLD) is a common condition affecting around 10-25% of the general adult population, 15% of children, and even > 50% of individuals who have type 2 diabetes mellitus. It is a major cause of liver-related morbidity, and cardiovascular (CV) mortality is a common cause of death. In addition to being the initial step of irreversible alterations of the liver parenchyma causing cirrhosis, about 1/6 of those who develop NASH are at risk also developing CV disease (CVD). More recently the acronym MAFLD (Metabolic Associated Fatty Liver Disease) has been preferred by many European and US specialists, providing a clearer message on the metabolic etiology of the disease. The suggestions for the management of NAFLD are like those recommended by guidelines for CVD prevention. In this context, the general approach is to prescribe physical activity and dietary changes the effect weight loss. Lifestyle change in the NAFLD patient has been supplemented in some by the use of nutraceuticals, but the evidence based for these remains uncertain. The aim of this Position Paper was to summarize the clinical evidence relating to the effect of nutraceuticals on NAFLD-related parameters. Our reading of the data is that whilst many nutraceuticals have been studied in relation to NAFLD, none have sufficient evidence to recommend their routine use; robust trials are required to appropriately address efficacy and safety.

Severity of Liver Fibrosis Is Associated with the Japanese Diet Pattern and Skeletal Muscle Mass in Patients with Nonalcoholic Fatty Liver Disease

It is not fully clear as to which dietary patterns are associated with the pathogenesis of nonalcoholic fatty liver disease (NAFLD) in Asia. We conducted a cross-sectional study of 136 consecutively recruited patients with NAFLD (49% female, median age 60 years). Severity of liver fibrosis was assessed using the Agile 3+ score, a recently proposed system based on vibration-controlled transient elastography. Dietary status was assessed using the 12-component modified Japanese diet pattern index (mJDI12). Skeletal muscle mass was assessed by bioelectrical impedance. Factors associated with intermediate-high-risk Agile 3+ scores and skeletal muscle mass (75th percentile or higher) were analyzed by multivariable logistic regression. After adjustment for confounders, such as age and sex, the mJDI12 (OR: 0.77; 95% CI: 0.61, 0.99) and skeletal muscle mass (75th percentile or higher) (OR: 0.23; 95% CI: 0.07, 0.77) were significantly associated with intermediate-high-risk Agile 3+ scores. Soybeans and soybean foods were significantly associated with skeletal muscle mass (75th percentile or higher) (OR: 1.02; 95% CI: 1.00, 1.04). In conclusion, the Japanese diet pattern was associated with the severity of liver fibrosis in Japanese patients with NAFLD. Skeletal muscle mass was also associated with the severity of liver fibrosis, and intake of soybeans and soybean foods.

Association of Healthy Dietary Patterns and Cardiorespiratory Fitness in the Community

Aims

To evaluate the associations of dietary indices and quantitative CRF measures in a large, community-based sample harnessing metabolomic profiling to interrogate shared biology.

Methods

Framingham Heart Study (FHS) participants underwent maximum effort cardiopulmonary exercise tests for CRF quantification (via peak VO 2 ) and completed semi-quantitative FFQs. Dietary quality was assessed by the Alternative Healthy Eating Index (AHEI) and Mediterranean-style Diet Score (MDS), and fasting blood concentrations of 201 metabolites were quantified.

Results

In 2380 FHS participants (54±9 years, 54% female, BMI 28±5 kg/m 2 ), 1-SD higher AHEI and MDS were associated with 5.1% (1.2 ml/kg/min, p<0.0001) and 4.4% (1.0 ml/kg/min, p<0.0001) greater peak VO 2 in linear models adjusted for age, sex, total energy intake, cardiovascular risk factors, and physical activity. In participants with metabolite profiling (N=1154), 24 metabolites were concordantly associated with both dietary indices and peak VO 2 in multivariable-adjusted linear models (FDR<5%). These metabolites included C6 and C7 carnitines, C16:0 ceramide, and dimethylguanidino valeric acid, which were higher with lower CRF and poorer dietary quality and are known markers of insulin resistance and cardiovascular risk. Conversely, C38:7 phosphatidylcholine plasmalogen and C38:7 and C40:7 phosphatidylethanolamine plasmalogens were associated with higher CRF and favorable dietary quality and may link to lower cardiometabolic risk.

Conclusion

Higher diet quality is associated with greater CRF cross-sectionally in a middle-aged community-dwelling sample, and metabolites highlight potential shared favorable effects on health.

Eating, diet, and nutrition for the treatment of non-alcoholic fatty liver disease

Nutrition and dietary interventions are a central component in the pathophysiology, but also a cornerstone in the management of patients with non-alcoholic fatty liver disease (NAFLD). Summarizing our rapidly advancing understanding of how our diet influences our metabolism and focusing on specific effects on the liver, we provide a comprehensive overview of dietary concepts to counteract the increasing burden of NAFLD. Specifically, we emphasize the importance of dietary calorie restriction independently of the macronutrient composition together with adherence to a Mediterranean diet low in added fructose and processed meat that seems to exert favorable effects beyond calorie restriction. Also, we discuss intermittent fasting as a type of diet specifically tailored to decrease liver fat content and increase ketogenesis, awaiting future study results in NAFLD. Finally, personalized dietary recommendations could be powerful tools to increase the effectiveness of dietary interventions in patients with NAFLD considering the genetic background and the microbiome, among others.

Nutritional Genomics in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common chronic condition associated with genetic and environmental factors in which fat abnormally accumulates in the liver. NAFLD is epidemiologically associated with obesity, type 2 diabetes, and dyslipidemia. Environmental factors, such as physical inactivity and an unbalanced diet, interact with genetic factors, such as epigenetic mechanisms and polymorphisms for the genesis and development of the condition. Different genetic polymorphisms seem to be involved in this context, including variants in PNPLA3, TM6SF2, PEMT, and CHDH genes, playing a role in the disease's susceptibility, development, and severity. From carbohydrate intake and weight loss to omega-3 supplementation and caloric restriction, different dietary and nutritional factors appear to be involved in controlling the onset and progression of NAFLD conditions influencing metabolism, gene, and protein expression. The polygenic risk score represents a sum of trait-associated alleles carried by an individual and seems to be associated with NAFLD outcomes depending on the dietary context. Understanding the exact extent to which lifestyle interventions and genetic predispositions can play a role in the prevention and management of NAFLD can be crucial for the establishment of a personalized and integrative approach to patients.

Dietary Patterns and Long-Term Outcomes in Patients with NAFLD: A Prospective Analysis of 128,695 UK Biobank Participants

Large longitudinal studies exploring the role of dietary patterns in the assessment of long-term outcomes of NAFLD are still lacking. We conducted a prospective analysis of 128,695 UK Biobank participants. Cox proportional hazards models were used to estimate the risk associated with two dietary patterns for long-term outcomes of NAFLD. During a median follow-up of 12.5 years, 1925 cases of end-stage liver disease (ESLD) and 12,466 deaths occurred in patients with NAFLD. Compared with patients in the lowest quintile, those in the highest quintile of the diet quality score was negatively associated with the risks of ESLD and all-cause mortality (HRQ5vsQ1: 0.76, 95% CI: 0.66−0.87, p < 0.001; HRQ5vsQ1: 0.84, 95% CI: 0.79−0.88, p < 0.001, respectively). NAFLD patients with high-quality carbohydrate patterns carried a 0.74-fold risk of ESLD and a 0.86-fold risk of all-cause mortality (HRQ5vsQ1: 0.74, 95% CI: 0.65−0.86, p < 0.001; HRQ5vsQ1: 0.86, 95% CI: 0.82−0.91, p < 0.001, respectively). For prudent dietary patterns rich in vegetables, fruits and fish, the adjusted HR Q5vsQ1 (95% CI) was 0.87 (0.76−0.99) and 0.94 (0.89−0.99) for ESLD and all-cause mortality of NAFLD patients. There was a U-shaped association between the meat-rich dietary pattern and all-cause mortality in patients with NAFLD. These findings suggest that a diet characterized by a high-quality, high intake of vegetables, fruits, fish and whole grains as well as an appropriate intake of meat, was associated with a lower risk of adverse outcomes of NAFLD.

Ideal Cardiovascular Health Metrics Are Associated with Reduced Severity of Hepatic Steatosis and Liver Fibrosis Detected by Transient Elastography

Life's Simple 7 (LS7) is the American Heart Association's (AHA) proposal for a healthy lifestyle, also known as cardiovascular health (CVH) metrics. However, the association between CVH metrics and the severity of hepatic steatosis and liver fibrosis detected by transient elastography is unknown. We performed a cross-sectional study using the data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) cycle. The controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were used to evaluate the severity of hepatic steatosis and liver fibrosis and to define NAFLD, advanced liver fibrosis, and cirrhosis. A total of 2679 participants were included. Multivariate linear regression analysis revealed that per 1-unit increase in the CVH metric, CAP and LSM decreased by 8.565 units and 0.274 units, respectively. In the multivariate logistic regression analysis, the risk of NAFLD, advanced liver fibrosis, and cirrhosis were 7, 10, and 6 times higher in the poor CVH group than in the ideal CVH group. Subgroup analysis indicated that CVD patients and non-Hispanic whites could benefit more from ideal CVH. In conclusion, adherence to ideal CVH metrics, as proposed by the AHA, can significantly reduce the risk of hepatic steatosis and liver fibrosis.

Dietary Quality and Relationships with Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) among United States Adults, Results from NHANES 2017-2018

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a new definition for the evidence of hepatic steatosis and metabolic dysfunctions. The specific role of the dietary factors in the development and progress of the disease are not well illuminated. Thus, we conducted this study on the associations between dietary quality assessed by five dietary quality indexes (Dietary Inflammatory Index, DII; Mediterranean diet, MED; Dietary Approach to Stop Hypertension, DASH; Alternate Healthy Eating Index diet, AHEI; Healthy Eating Indices, HEI) and MAFLD phenotypes. This study was extracted from the latest NHANES 2017-2018 wave. Demographic information, health status, lifestyles, and dietary habits were reported in the questionnaire. Multivariate logistic regression and multivariate ordinal logistic regression methods were applied to explore the associations between dietary quality indexes and MAFLD or MAFLD with liver fibrosis. The weighted prevalence of Non-MAFLD, MAFLD without fibrosis, and MAFLD with fibrosis were 47.05%, 36.67%, and 16.28%, respectively, at the cutoff value of a median Controlled Attenuation Parameter (CAP) 248 dB/m and a median Liver Stiffness Measurement (LSM) 6.3 kPa. When the diagnostic cutoff values of CAP changed to 285 dB/m, the weighted prevalence of Non-MAFLD, MAFLD without liver fibrosis, and MAFLD with fibrosis turned to 64.62%, 22.08%, and 13.30%, respectively. All five dietary quality indexes, including DII, HEI-2015, AHEI, DASH, and MED, were all significantly associated with MAFLD phenotypes. DII was positively associated with MAFLD phenotypes, while other four dietary quality indexes, including HEI-2015, AHEI, DASH, and MED, were significantly associated with lower risk of MAFLD phenotypes. MAFLD is becoming a threatening public health concern among adult Americans and dietary quality is markedly associated with MAFLD phenotypes.

Trends in Diet Quality by Race/Ethnicity among Adults in the United States for 2011-2018

This study aimed to investigate time trends in diet quality and the consumption of major food groups and nutrients by race/ethnicity among adults in the United States. Dietary data from 19,192 adults aged ≥ 20 years from four National Health and Nutrition Survey (NHANES) cycles (2011-2018) were included. The Healthy Eating Index (HEI) 2015 scores (range: 0-100; higher scores indicate better diet quality) and dietary consumption of food groups and nutrients were estimated for each cycle. Linear regression was used to test trends. For the overall population, the estimated overall HEI-2015 scores significantly decreased (p for trend = 0.011). However, decreases were observed in the estimated consumption of added sugars and total carbohydrates, while the estimated consumption of soy products and polyunsaturated fatty acids was significantly increased. A significant decrease in overall HEI-2015 score was observed in the non-Hispanic white group, but not in other racial/ethnic groups. Decreases in added sugar intake were found in the non-Hispanic black and Hispanic groups; sodium intake significantly decreased in the non-Hispanic Asian group. From 2011 to 2018, there was a decrease in estimated overall diet quality in US adults; however, there were improvements in certain nutrients and dietary components. Nevertheless, disparities in diet quality exist among racial/ethnic groups.

The role of dietary factors in nonalcoholic fatty liver disease to hepatocellular carcinoma progression: A systematic review

BACKGROUND AND AIMS

Dietary factors play an important role in promoting nonalcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC) development through regulation of metabolism and inflammation. However, so far there was no evidence regarding how dietary factors may influence different disease outcomes in the NAFLD to HCC progression. Our study aimed to comprehensively evaluate the role of dietary factors on the risk of progression from NAFLD to HCC.

METHODS

A comprehensive literature research was conducted in PubMed, Web of Science and Embase databases to identify case-control and cohort studies published up to March 15, 2022 in English. We included studies investigating associations of food and beverage items (excluding alcohol), food groups, dietary patterns, and dietary habits with incidence risk of four main chronic liver diseases involved in the NAFLD-to-HCC progression (i.e., NAFLD, liver fibrosis, liver cirrhosis, and HCC). Three researchers independently performed the literature search, selected eligible articles, performed data abstraction and evaluated study quality. After evaluating adequacy and credibility of the associations reported for each dietary factor and each liver disease outcome, we summarized and evaluated the consistency of associations based on a priori determined criteria considering study design and the proportion of significant associations.

RESULTS

There were 109 studies included in this review (47 on NAFLD, 1 on liver fibrosis, 6 on liver cirrhosis, and 55 on HCC). Consistent evidence suggested that higher dietary inflammatory potential was associated with increased risk of both NAFLD and HCC whereas Mediterranean diet was associated with lower risk of both diseases. Additionally, greater conformity to the Healthy Eating Index, Dietary Approaches to Stop Hypertension score, and Mediterranean Diet Score, and dietary patterns with high dietary antioxidant capacity reduced NAFLD risk. Some specific foods including soft drinks and red and/or processed meat were associated with increased NAFLD risk while total vegetables and spinach were associated with reduced NAFLD risk. Coffee and white meat consumption were inversely related to HCC risk.

CONCLUSIONS

Dietary patterns or individual foods representing a more anti-inflammatory potential were associated with reduced risk of both NAFLD and HCC, which implied diet-induced inflammation may impact NAFLD progression towards HCC.

Therapies for non-alcoholic fatty liver disease: A 2022 update

The incidence of non-alcoholic fatty liver disease (NAFLD) is rapidly increasing and lifestyle interventions to treat this disease by addressing the underlying metabolic syndrome are often limited. Many pharmacological interventions are being studied to slow or even reverse NAFLD progression. This review for hepatologists aims to provide an updated understanding of the pathogenesis of NAFLD, current recommended therapies, and the most promising treatment options that are currently under development.

Association between Mediterranean Diet and Fatty Liver in Women with Overweight and Obesity

Obesity is a risk factor for NAFLD. However, not all people with obesity have an excessive intrahepatic fat content. Adherence to a high-quality dietary pattern may also promote liver health in obesity. A cross-sectional study of 2967 women with overweight and obesity was carried out to assess the association between a Mediterranean diet and fatty liver. All women underwent clinical examination, anthropometric measurements, blood sampling, ultrasound measurements of abdominal visceral and subcutaneous fat, and assessment of adherence to the Mediterranean diet using the 14-item MEDAS questionnaire. Fatty liver index (FLI), NAFLD fatty liver steatosis (NAFLD-FLS) and hepatic steatosis index (HSI) were calculated. In women with obesity, the MEDAS score was inversely associated with FLI (β = −0.60, 95% CI: −1.04, −0.16, p = 0.008), NAFLD-FLS (β = −0.092, 95% CI: −0.134, −0.049, p < 0.001) and HSI (β = −0.17, 95% CI: −0.30, −0.04, p = 0.011). Stronger associations were observed in premenopausal women with obesity. Mediterranean diet was inversely associated with NAFLD-FLS in women with overweight, independently of menopausal status. In conclusion, Mediterranean diet is associated with a better liver status in women with overweight and obesity. This may have a public health impact and be useful in drafting nutritional guidelines for NAFLD.

One size does not fit all; practical, personal tailoring of the diet to NAFLD patients

Different dietary regimens for weight loss have developed over the years. Since the most evidenced treatment for non-alcoholic fatty liver disease (NAFLD) is weight reduction, it is not surprising that more diets targeting obesity are also utilized for NAFLD treatment. However, beyond the desired weight loss effects, one should not ignore the dietary composition of each diet, which may not necessarily be healthy or safe over the long term for hepatic and extrahepatic outcomes, especially cardiometabolic outcomes. Some of these diets are rich in saturated fat and red meat, are very strict, and require close medical supervision. Some may also be very difficult to adhere to for long periods, thus reducing the patient's motivation. The evidence for a direct benefit to NAFLD by restrictive diets such as very-low-carb, ketogenic, very-low-calorie diets, and intermittent fasting is scarce, and the long-term safety has not been tested. Nowadays, the approach is that the diet should be tailored to the patient's cultural and personal preferences. There is strong evidence for the independent protective association of NAFLD with a diet based on healthy eating patterns of minimally-processed foods, low in sugar and saturated fat, high in polyphenols, and healthy types of fats. This leads to the conclusion that a Mediterranean diet should serve as a basis that can be restructured into other kinds of diets. This review will elaborate on the different diets and their role in NAFLD. It will provide a practical guide to tailor the diet to the patients without compromising its composition and safety.

Quality standards for the management of non-alcoholic fatty liver disease (NAFLD): consensus recommendations from the British Association for the Study of the Liver and British Society of Gastroenterology NAFLD Special Interest Group

Non-alcoholic fatty liver disease (NAFLD) is common, affecting approximately 25% of the general population. The evidence base for the investigation and management of NAFLD is large and growing, but there is currently little practical guidance to support development of services and delivery of care. To address this, we produced a series of evidence-based quality standard recommendations for the management of NAFLD, with the aim of improving patient care. A multidisciplinary group of experts from the British Association for the Study of the Liver and British Society of Gastroenterology NAFLD Special Interest Group produced the recommendations, which cover: management of people with, or at risk of, NAFLD before the gastroenterology or liver clinic; assessment and investigations in secondary care; and management in secondary care. The quality of evidence for each recommendation was evaluated by the Grading of Recommendation Assessment, Development and Evaluation tool. An anonymous modified Delphi voting process was conducted individually by each member of the group to assess the level of agreement with each statement. Statements were included when agreement was 80% or greater. From the final list of statements, a smaller number of auditable key performance indicators were selected to allow services to benchmark their practice. It is hoped that services will review their practice against our recommendations and key performance indicators and institute service development where needed to improve the care of patients with NAFLD.

Levels of abdominal adipose tissue and metabolic-associated fatty liver disease (MAFLD) in middle age according to average fast-food intake over the preceding 25 years: the CARDIA Study

BACKGROUND

Higher levels of intra-abdominal adipose tissue (IAAT) comprising visceral adipose tissue (VAT), intermuscular adipose tissue (IMAT), and liver fat are posited drivers of obesity-related chronic disease risk. Fast food is hypothesized to contribute to IAAT patterns.

OBJECTIVES

We quantified levels of abdominal subcutaneous adipose tissue (SAT), IAAT, and odds of metabolic-associated fatty liver disease (MAFLD) in middle age according to average fast-food intake over the preceding 25 y.

METHODS

We analyzed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants underwent 6 clinical exams and measurements over 25 y with computed tomography-measured VAT, SAT, and IMAT (n = 3156), plus MAFLD defined by liver attenuation (≤40 Hounsfield units) and 1 metabolic abnormality at year 25 (2010, n = 3001, n cases = 302). We estimated means of VAT, SAT, IMAT, and liver attenuation at the year 25 exam according to categories of average fast-food intake over the previous 25 y adjusted for sociodemographic and lifestyle factors and logistic regression to estimate the odds ratio of MAFLD at year 25.

RESULTS

With higher average fast-food intake over 25 y (categorized as follows: never-1×/mo, >1×-3×/mo, 1-<2×/wk, 2-<3×/wk, ≥3×/wk), there were monotonic higher levels of VAT (98.5, 127.6, 134.5, 142.0, 145.5 cm3), P-trend < 0.0001, which were consistent across anthropometrically classified obesity categories. There was a similar pattern with liver fat. There were higher levels of IMAT and SAT with higher fast-food intake (P-trend = 0.003, 0.0002, respectively), with amounts leveling off at ≥2×/wk. In addition, compared with participants who ate fast food never-1×/mo, there were monotonic higher odds of having MAFLD at year 25 with higher average fast-food intake, with participants who ate fast food ≥3×/wk having an OR of MAFLD = 5.18 (95% CI: 2.87, 9.37).

CONCLUSIONS

There were monotonic higher levels of VAT, liver fat, and odds of having MAFLD in middle age according to higher average fast-food intake over the preceding 25 y.

Interactions of physical activity, muscular fitness, adiposity, and genetic risk for NAFLD

Genetic predisposition and unhealthy lifestyle are risk factors for nonalcoholic fatty liver disease (NAFLD). We investigated whether the genetic risk of NAFLD is modified by physical activity, muscular fitness, and/or adiposity. In up to 242,524 UK Biobank participants without excessive alcohol intake or known liver disease, we examined cross-sectional interactions and joint associations of physical activity, muscular fitness, body mass index (BMI), and a genetic risk score (GRS) with alanine aminotransferase (ALT) levels and the proxy definition for suspected NAFLD of ALT levels > 30 U/L in women and >40 U/L in men. Genetic predisposition to NAFLD was quantified using a GRS consisting of 68 loci known to be associated with chronically elevated ALT. Physical activity was assessed using accelerometry, and muscular fitness was estimated by measuring handgrip strength. We found that increased physical activity and grip strength modestly attenuate genetic predisposition to elevation in ALT levels, whereas higher BMI markedly amplifies it (all p values < 0.001). Among those with normal weight and high level of physical activity, the odds of suspected NAFLD were 1.6-fold higher in those with high versus low genetic risk (reference group). In those with high genetic risk, the odds of suspected NAFLD were 12-fold higher in obese participants with low physical activity versus those with normal weight and high physical activity (odds ratio for NAFLD = 19.2 and 1.6, respectively, vs. reference group). Conclusion: In individuals with high genetic predisposition for NAFLD, maintaining a normal body weight and increased physical activity may reduce the risk of NAFLD.