Hypercaloric diets with increased meal frequency, but not meal size, increase intrahepatic triglycerides: a randomized controlled trial

Induction of Fructose Mediated De Novo Lipogenesis Coexists with the Upregulation of Mitochondrial Oxidative Function in Mice Livers

BACKGROUND

Dysfunctional mitochondrial metabolism and sustained de novo lipogenesis (DNL) are characteristics of metabolic dysfunction-associated steatotic liver disease (MASLD), a comorbidity of obesity and type 2 diabetes. Fructose, a common sweetener and a potent inducer of lipogenesis, contributes to the etiology of MASLD.

OBJECTIVES

Our goal was to determine whether higher rates of DNL, through its biochemical relationships with mitochondria, can contribute to dysfunctional induction of oxidative networks in the liver.

METHODS

Male C57BL/6JN mice were given a low-fat (10% fat kcal, 49.9% corn starch kcal), high-fat (HF; 60% fat kcal), or HF/high-fructose diet (HF/HFr; 25% fat kcal, 34.9% fructose kcal) for 24 wk. In a follow-up study, mice on normal feed pellets were provided either 30% fructose in drinking water (FW) to induce hepatic DNL or regular water (NW) for 14 d. Hepatic mitochondria and liver tissue were used to determine oxygen consumption, reactive oxygen species (ROS) generation, tricarboxylic acid (TCA) cycle activity, and gene/protein expression profiles.

RESULTS

Hepatic steatosis remained similar between HF and HF/HFr fed mice livers. However, lipogenic and lipid oxidation gene expression profiles and the induction of TCA cycle metabolism were all higher (P ≤ 0.05) in HF/HFr livers. Under fed conditions, the upregulation of DNL in FW livers occurred in concert with higher mitochondrial oxygen consumption (basal; 1.7 ± 0.21 compared with 3.3 ± 0.14 nmoles/min, P ≤ 0.05), higher ROS (0.87 ± 0.09 compared with 1.25 ± 0.12 μM, P ≤ 0.05) and higher flux through TCA cycle components P ≤0.05. Furthermore, TCA cycle activity and lipid oxidation remained higher during fasting in the FW livers P ≤ 0.05.

CONCLUSIONS

Our results show that fructose administration to mice led to the concurrent induction of mitochondrial oxidative networks and DNL in the liver. Sustained induction of both DNL and mitochondrial oxidative function could accelerate cellular stress and metabolic dysfunction during MASLD.

The ins and outs of liver fat metabolism: The effect of phenotype and diet on risk of intrahepatic triglyceride accumulation

In health, the liver is a metabolically flexible organ that plays a key role in regulating systemic lipid and glucose concentrations. There is a constant flux of fatty acids (FAs) to the liver from multiple sources, including adipose tissue, dietary, endogenously synthesized from non-lipid precursors, intrahepatic lipid droplets and recycling of triglyceride-rich remnants. Within the liver, FAs are used for triglyceride synthesis, which can be oxidized, stored or secreted in very low-density lipoproteins into the systemic circulation. The processes of FA uptake, FA synthesis and the intracellular partitioning of FAs into storage, oxidation or secretory pathways are tightly regulated. An imbalance in these processes causes intrahepatic triglyceride to accumulate and is associated with the development of metabolic dysfunction-associated steatotic liver disease. It is well appreciated that many factors can influence intrahepatic FA partitioning, and although there is good evidence that both phenotype (e.g., sex, ethnicity and adiposity) and dietary macronutrient composition can play a role in intrahepatic triglyceride accumulation, their interaction remains poorly understood. The aim of this review is to explore how the respective pathways of FA delivery, synthesis and disposal are altered by phenotype and understand how dietary macronutrient composition might influence the partitioning of FAs in the liver in vivo, in humans.

Diverting hepatic lipid fluxes with lifestyles revision and pharmacological interventions as a strategy to tackle steatotic liver disease (SLD) and hepatocellular carcinoma (HCC)

Steatotic liver disease (SLD) and Hepatocellular Carcinoma (HCC) are characterised by a substantial rewiring of lipid fluxes caused by systemic metabolic unbalances and/or disrupted intracellular metabolic pathways. SLD is a direct consequence of the interaction between genetic predisposition and a chronic positive energy balance affecting whole-body energy homeostasis and the function of metabolically-competent organs. In this review, we discuss how the impairment of the cross-talk between peripheral organs and the liver stalls glucose and lipid metabolism, leading to unbalances in hepatic lipid fluxes that promote hepatic fat accumulation. We also describe how prolonged metabolic stress builds up toxic lipid species in the liver, and how lipotoxicity and metabolic disturbances drive disease progression by promoting a chronic activation of wound healing, leading to fibrosis and HCC. Last, we provide a critical overview of current state of the art (pre-clinical and clinical evidence) regarding mechanisms of action and therapeutic efficacy of candidate SLD treatment options, and their potential to interfere with SLD/HCC pathophysiology by diverting lipids away from the liver therefore improving metabolic health.

Circadian Deregulation: Back Facing the Sun Toward Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) Development

Earth's rotation around its axis has pressured its inhabitants to adapt to 24 h cycles of day and night. Humans adapted their own circadian rhythms to the Earth's rhythms with a light-aligned awake-sleep cycle. As a consequence, metabolism undergoes drastic changes throughout the circadian cycle and needs plasticity to cope with opposing conditions in the day (when there is an increase in energy demands and food availability), and during the night (when prolonged fasting couples with cyclic changes in the energy demands across the sleep stages). In the last century, human behavior changed dramatically with a disregard for the natural circadian cycles. This misalignment in sleep and eating schedules strongly modulates the metabolism and energy homeostasis, favoring the development of obesity, metabolic syndrome, and metabolic dysfunction-associated steatotic liver disease (MASLD). This review summarizes the effects of circadian disruption, with a particular focus on the feeding and sleep cycles in the development of MASLD and hepatocellular carcinoma.

A healthy lifestyle is prospectively associated with lower onset of metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is associated with an unhealthy lifestyle. However, there is limited prospective evidence regarding the association between combined lifestyle factors and MASLD. This study aims to test the association of a combination of lifestyle components, expressed as a healthy lifestyle index (HLI), and unhealthful eating behavior habits with MASLD, insulin resistance (IR), liver fibrosis, and metabolic dysfunction-associated steatohepatitis.

METHODS

A prospective cohort study was conducted among participants of metabolic and hepatic screening surveys. MASLD was evaluated by ultrasonography or controlled attenuation parameter at 2 time points to assess new-onset, persistence, or remission, and IR was estimated by homeostasis model assessment. Presumed liver fibrosis and metabolic dysfunction-associated steatohepatitis were evaluated using FibroMax biomarkers. The HLI was calculated as the sum of 4 lifestyle components: nonsmoking, healthy weight, healthy diet, and physical activity.

RESULTS

The final cohort included 315 subjects with 6.7 years of follow-up, 40-70 years old. In multivariable analyses, a favorable lifestyle (≥3 components) was independently associated with lower odds of new-onset MASLD (OR = 0.42; 95% CI: 0.19-0.90). Similarly, a favorable lifestyle was associated with lower odds of new-onset/persistent (vs. never/remission) MASLD and IR, respectively (OR = 0.49; 95% CI: 0.30-0.80; OR = 0.40; 95% CI: 0.24-0.66). There was a dose-response association between HLI and new-onset/persistent MASLD and IR. A favorable lifestyle was associated with lower odds of new-onset metabolic dysfunction-associated steatohepatitis (OR = 0.50; 95% CI: 0.27-0.95). Adjusting for HLI, unhealthful eating behavior habits were associated with higher odds of MASLD prevalence (OR = 1.81; 95% CI: 1.07-3.06).

CONCLUSIONS

Adherence to a healthy lifestyle is prospectively associated with lower odds of MASLD, markers of liver damage, and IR. A holistic approach that considers overall lifestyle and eating behavior may be useful for preventing MASLD.

Manipulation of feeding patterns in high fat diet fed rats improves microbiota composition dynamics, inflammation and gut-brain signaling

Chronic consumption of high fat (HF) diets has been shown to increase meal size and meal frequency in rodents, resulting in overeating. Reducing meal frequency and establishing periods of fasting, independently of caloric intake, may improve obesity-associated metabolic disorders. Additionally, diet-driven changes in microbiota composition have been shown to play a critical role in the development and maintenance of metabolic disorders. In this study, we used a pair-feeding paradigm to reduce meal frequency and snacking episodes while maintaining overall intake and body weight in HF fed rats. We hypothesized that manipulation of feeding patterns would improve microbiota composition and metabolic outcomes. Male Wistar rats were placed in three groups consuming either a HF, low fat diet (LF, matched for sugar), or pair-fed HF diet for 7 weeks (n = 11-12/group). Pair-fed animals received the same amount of food consumed by the HF fed group once daily before dark onset (HF-PF). Rats underwent oral glucose tolerance and gut peptide cholecystokinin sensitivity tests. Bacterial DNA was extracted from the feces collected during both dark and light cycles and sequenced via Illumina MiSeq sequencing of the 16S V4 region. Our pair-feeding paradigm reduced meal numbers, especially small meals in the inactive phase, without changing total caloric intake. This shift in feeding patterns reduced relative abundances of obesity-associated bacteria and maintained circadian fluctuations in microbial abundances. These changes were associated with improved gastrointestinal (GI) function, reduced inflammation, and improved glucose tolerance and gut to brain signaling. We concluded from these data that targeting snacking may help improve metabolic outcomes, independently of energy content of the diet and hyperphagia.

Current strategies for nonalcoholic fatty liver disease treatment (Review)

Nonalcoholic fatty liver disease (NAFLD), the most common chronic hepatic disease, has become a leading health problem worldwide. The present review summarized the methods and mechanisms to treat NAFLD, including the Mediterranean diet, physical activity and exercise, bariatric surgery and specific therapeutic agents, including statins, peroxisome proliferator‑activated receptor agonists, cenicriviroc and farnesoid X receptor agonists. Biologically active substances, such as peptides, alkaloids, polyphenolic compounds, silymarin, antibiotics, fatty acids, vitamins, probiotics, synbiotics and lamiaceae have also demonstrated actions that combat NAFLD. Considering their different mechanisms of action, combining some of them may prove an efficacious treatment for NAFLD. In this light, the present review describes recent progress and future prospects in treating NAFLD.

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.

OBJECTIVES

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

METHODS

The presence of MAFLD was determined in the United Kingdom 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.

CONCLUSIONS

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

Dietary characteristics associated with the risk of non-alcoholic fatty liver disease and metabolic dysfunction-associated steatotic liver disease in non-obese Japanese participants: A cross-sectional study

Background and Aim

Dietary characteristics associated with non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD) in non-obese patients remain to be elucidated. This study examined the association of NAFLD and MASLD with dietary characteristics according to obesity status.

Methods

We performed a cross-sectional study of 15 135 participants (n = 7568 men and 7567 women) aged 35-74 years using data of annual health checks between 2008 and 2020. Obesity was defined as BMI ≥ 25 kg/m2. Diagnosis of fatty liver was based on abdominal ultrasonography. Fatty-liver-related dietary characteristics were assessed using a self-administered questionnaire.

Results

For non-obese participants, NAFLD was found in 31.0% of men and 19.4% of women. Non-obese MASLD was found in 27.6% of men and 18.1% of women. Multivariable-adjusted stepwise logistic regression analysis indicated that, in males, both non-obese NAFLD and non-obese MASLD were significantly and negatively associated with "often eat sesame/nuts", and positively associated with "often eat noodles/rice bowl" and "often eat evening meal" (P < 0.05). For non-obese women, both NAFLD and MASLD were significantly and positively associated with "often eat sweet buns/bread with fillings" (P < 0.05). Adjusted analyses showed that all dietary characteristics were not significantly associated with the risk of NAFLD/MASLD in obese men and women.

Conclusion

This cross-sectional study indicates the existence of sex and obesity differences in the association of NAFLD and MASLD with dietary characteristics. Our findings suggest that some dietary characteristics are associated with NAFLD and MASLD prevalence in non-obese Japanese participants.

Chrononutrition in traditional European medicine-Ideal meal timing for cardiometabolic health promotion

Meal timing plays a crucial role for cardiometabolic health, given the circadian regulation of cardiometabolic function. However, to the best of our knowledge, no concept of meal timing exists in traditional European medicine (TEM). Therefore, in this narrative review, we aim to define the optimal time slot for energy intake and optimal energy distribution throughout the day in a context of TEM and explore further implications. By reviewing literature published between 2002 and 2022, we found that optimal timing for energy intake may be between 06:00 and 09:00, 12:00 and 14:00, and between 15:00 and 18:00, with high energy breakfast, medium energy lunch and low energy dinner and possibly further adjustments according to one's chronotype and genetics. Also, timing and distribution of energy intake may serve as a novel therapeutic strategy to optimize coction, a concept describing digestion and metabolism in TEM. Please cite this article as: Eberli NS, Colas L, Gimalac A. Chrononutrition in traditional European medicine-Ideal meal timing for cardiometabolic health promotion. J Integr Med. 2024; 22(2);115-125.

Lipid metabolism in the immune niche of tumor-prone liver microenvironment

The liver is a common primary site not only for tumorigenesis, but also for cancer metastasis. Advanced cancer patients with liver metastases also show reduced response rates and survival benefits when treated with immune checkpoint inhibitors. Accumulating evidence has highlighted the importance of the liver immune microenvironment in determining tumorigenesis, metastasis-organotropism, and immunotherapy resistance. Various immune cells such as T cells, natural killer and natural killer T cells, macrophages and dendritic cells, and stromal cells including liver sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, and hepatocytes are implicated in contributing to the immune niche of tumor-prone liver microenvironment. In parallel, as the major organ for lipid metabolism, the increased abundance of lipids and their metabolites is linked to processes crucial for nonalcoholic fatty liver disease and related liver cancer development. Furthermore, the proliferation, differentiation, and functions of hepatic immune and stromal cells are also reported to be regulated by lipid metabolism. Therefore, targeting lipid metabolism may hold great potential to reprogram the immunosuppressive liver microenvironment and synergistically enhance the immunotherapy efficacy in the circumstance of liver metastasis. In this review, we describe how the hepatic microenvironment adapts to the lipid metabolic alterations in pathologic conditions like nonalcoholic fatty liver disease. We also illustrate how these immunometabolic alterations promote the development of liver cancers and immunotherapy resistance. Finally, we discuss the current therapeutic options and hypothetic combination immunotherapies for the treatment of advanced liver cancers.

Ramadan fasting model exerts hepatoprotective, anti-obesity, and anti-hyperlipidemic effects in an experimentally-induced nonalcoholic fatty liver in rats

BACKGROUND

The epidemic of nonalcoholic fatty liver disease (NAFLD) and its metabolic effects present a serious public health concern. We hypothesized that the Ramadan fasting model (RFM), which involves fasting from dawn to dusk for a month, could provide potential therapeutic benefits and mitigate NAFLD. Accordingly, we aimed to validate this hypothesis using obese male rats.

METHODS

Rats were split into two groups (n = 24 per group), and they were given either a standard (S) or high-fat diet (HFD) for 12 weeks. During the last four weeks of the study period, both S- and HFD-fed rats were subdivided into eight groups to assess the effect of RFM with/without training (T) or glucose administration (G) on the lipid profile, liver enzymes, and liver structure (n = 6/group).

RESULTS

The HFD+RFM group exhibited a significantly lower final body weight than that in the HFDC group. Serum cholesterol, low-density lipoprotein, and triglyceride levels were significantly lower in the HFD+RFM, HFD+RFM+T, and HFD+RFM+G groups than those in the HFDC group. Compared with the HFDC group, all groups had improved serum high-density lipoprotein levels. Furthermore, HFD groups subjected to RFM had reduced serum levels of aspartate transaminase and alanine transaminase compared with those of the HFD-fed group. Moreover, the liver histology improved in rats subjected to RFM compared with that of HFD-fed rats, which exhibited macro- and micro-fat droplet accumulation.

CONCLUSION

RFM can induce positive metabolic changes and improve alterations associated with NAFLD, including weight gain, lipid profile, liver enzymes, and hepatic steatosis.

Lifestyle factors affecting new-onset nonalcoholic fatty liver disease

Evidence for the influence of lifestyle factors on nonalcoholic fatty liver disease (NAFLD) onset is limited because the association between lifestyle factors and NAFLD has been reported mostly in cross-sectional studies. Our purpose was to elucidate which lifestyle factors are associated with NAFLD onset by performing a longitudinal study. This was a longitudinal study of 1,713 Japanese participants who underwent multiple health checkups from June 2013 to the end of March 2018 and were not diagnosed with NAFLD at the first health checkup at Watari Hospital in Fukushima, Japan. Baseline characteristics, including lifestyle factors, were compared among participants with and without NAFLD. Cox proportional hazards models were used to identify the association between lifestyle factors and NAFLD onset. Among the 1,713 participants, 420 (24.5 %) developed NAFLD during the observation period (median 47 months). There were significant differences in body mass index and hepatobiliary enzyme levels between participants with and without NAFLD. In Cox proportional hazards models, eating between meals (hazard ratio (HR): 2.08, 95 % confidence interval (CI): 1.25-3.45, p < 0.01) and eating fast (HR: 1.59, 95 % CI: 1.26-2.00, p < 0.01) were risk factors for NAFLD onset in men and women, respectively. Moreover, fast walking was a protective factor against NAFLD onset in women (HR: 0.76, 95 % CI: 0.60-0.96, p = 0.02). These findings could help to identify patients at risk and prevent future NAFLD onset.

Time-Restricted Fasting Improves Liver Steatosis in Non-Alcoholic Fatty Liver Disease-A Single Blinded Crossover Trial

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with visceral adiposity. We assessed the effectiveness of time-restricted fasting (TRF) for 16 h daily without calorie restrictions compared to standard care (SC; diet and lifestyle advice) in improving visceral adiposity and steatosis via controlled attenuation parameter (CAP).

METHODS

In a prospective single-blind randomized controlled trial, 32 participants with NAFLD were randomly assigned to TRF or SC for 12 weeks. The secondary endpoints were changes in liver stiffness, anthropometry, blood pressure, and other metabolic factors.

RESULTS

Twenty-eight participants completed the first arm of the study (TRF = 14, SC = 14), with 23 completing the crossover arm (TRF = 10, SC = 13). The baseline demographics were similar between the groups. Intermittent fasting caused a significant decrease in hepatic steatosis (p = 0.038), weight (p = 0.005), waist circumference (p = 0.001), and BMI (p = 0.005) compared to standard care. Intermittent fasting also resulted in additional within-group changes that were not seen in the standard care intervention.

CONCLUSION

TRF offers superior improvements in patients with NAFLD, improving steatosis, weight, and waist circumference despite a lack of change in overall caloric intake. Time-restricted fasting should be considered as a primary weight loss intervention in the context of NAFLD.

TRIAL REGISTRATION

ACTRN12613000935730.

Association of food intake with a risk of metabolic dysfunction-associated fatty liver disease: a cross-sectional study

Background

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common liver disease, the risk of which can be increased by poor diet. The objective of this study was to evaluate the associations between food items and MAFLD, and to propose reasonable dietary recommendations for the prevention of MAFLD.

Methods

Physical examination data were collected from April 2015 through August 2017 at Nanping First Hospital (n = 3,563). Dietary intakes were assessed using a semi-quantitative food frequency questionnaire. The association between food intake and the risk of MAFLD was assessed by using the inverse probability weighted propensity score.

Results

Beverages (soft drinks and sugar-sweetened beverages) and instant noodles were positively associated with MAFLD risk, adjusting for smoking, drinking, tea intake, and weekly hours of physical activity [adjusted odds ratio (ORadjusted): 1.568; P = 0.044; ORadjusted: 4.363; P = 0.001]. Milk, tubers, and vegetables were negatively associated with MAFLD risk (ORadjusted: 0.912; P = 0.002; ORadjusted: 0.633; P = 0.007; ORadjusted: 0.962; P = 0.028). In subgroup analysis, the results showed that women [odds ratio (OR): 0.341, 95% confidence interval (CI): 0.172-0.676] had a significantly lower risk of MAFLD through consuming more tubers than men (OR: 0.732, 95% CI: 0.564-0.951).

Conclusions

These findings suggest that reducing consumption of beverages (soft drinks and sugar-sweetened beverages) and instant noodles, and consuming more milk, vegetables, and tubers may reduce the risk of MAFLD.

Non-alcoholic fatty liver disease: Dietary and nutraceutical approaches

Non-alcoholic fatty liver disease (NAFLD), defined as the presence of fat accumulation in imaging or histology in more than 5% of hepatocytes and exclusion of other causes for secondary hepatic fat accumulation, is one of the major causes of chronic liver disease worldwide. Metabolic syndrome is associated with an increased risk of progression from NAFLD to non-alcoholic steatohepatitis (NASH), fibrosis, and forthcoming liver failure. Also, genetic predisposition contributes to the risk of NAFLD development. This review explores the role of diets and nutraceuticals in delaying the development and the evolution of NAFLD to chronic liver disease. The Mediterranean diet, high-protein diet, low-carbohydrate/high-fat diet, high-carbohydrate/low-fat diet, and intermittent fasting are the dietary approaches investigated given the presence of relevant literature data. Moreover, this review focused on nutraceuticals with proven efficacy in ameliorating NAFLD and grouped them into four different categories: plant-based nutraceuticals (Ascophyllum nodosum and Fucus vesiculosus, Silymarin, Berberine, Curcumin, Resveratrol, Nigella sativa, Quercetin), vitamin-like substances (vitamin E, vitamin D, vitamin C, coenzyme Q10, inositol), fatty acids (omega-3), and microbiota-management tools (probiotics).

Important food sources of fructose-containing sugars and adiposity: A systematic review and meta-analysis of controlled feeding trials

BACKGROUND

Sugar-sweetened beverages (SSBs) providing excess energy increase adiposity. The effect of other food sources of sugars at different energy control levels is unclear.

OBJECTIVES

To determine the effect of food sources of fructose-containing sugars by energy control on adiposity.

METHODS

In this systematic review and meta-analysis, MEDLINE, Embase, and Cochrane Library were searched through April 2022 for controlled trials ≥2 wk. We prespecified 4 trial designs by energy control: substitution (energy-matched replacement of sugars), addition (energy from sugars added), subtraction (energy from sugars subtracted), and ad libitum (energy from sugars freely replaced). Independent authors extracted data. The primary outcome was body weight. Secondary outcomes included other adiposity measures. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence.

RESULTS

We included 169 trials (255 trial comparisons, n = 10,357) assessing 14 food sources at 4 energy control levels over a median 12 wk. Total fructose-containing sugars increased body weight (MD: 0.28 kg; 95% CI: 0.06, 0.50 kg; P_MD = 0.011) in addition trials and decreased body weight (MD: -0.96 kg; 95% CI: -1.78, -0.14 kg; P_MD = 0.022) in subtraction trials with no effect in substitution or ad libitum trials. There was interaction/influence by food sources on body weight: substitution trials [fruits decreased; added nutritive sweeteners and mixed sources (with SSBs) increased]; addition trials [dried fruits, honey, fruits (≤10%E), and 100% fruit juice (≤10%E) decreased; SSBs, fruit drink, and mixed sources (with SSBs) increased]; subtraction trials [removal of mixed sources (with SSBs) decreased]; and ad libitum trials [mixed sources (with/without SSBs) increased]. GRADE scores were generally moderate. Results were similar across secondary outcomes.

CONCLUSIONS

Energy control and food sources mediate the effect of fructose-containing sugars on adiposity. The evidence provides a good indication that excess energy from sugars (particularly SSBs at high doses ≥20%E or 100 g/d) increase adiposity, whereas their removal decrease adiposity. Most other food sources had no effect, with some showing decreases (particularly fruits at lower doses ≤10%E or 50 g/d). This trial was registered at clinicaltrials.gov as NCT02558920 (https://clinicaltrials.gov/ct2/show/NCT02558920).

Self-Reported Eating-Occasion Frequency and Timing are Reproducible and Relatively Valid in the American Cancer Society Cancer Prevention Study-3 Diet Assessment Substudy

BACKGROUND

Accurate assessment of eating-occasion behaviors, such as timing, frequency, and consumption intervals, is important for evaluating associations with obesity and other chronic diseases.

OBJECTIVES

The main objective of this study was to assess the relative validity of a 24-hour grid approach to assess eating-occasion timing and frequency in comparison to data derived from repeated 24-hour dietary recalls (DRs). A second objective was to assess the 1-year test-retest reproducibility of the 24-hour grid.

METHODS

Between 2015 and 2016, 626 participants in the Cancer Prevention Study-3 (CPS-3) Diet Assessment Substudy (mean age, 52 years; age range, 31-70 years; 64% female; 64% non-Hispanic white, 22% non-Hispanic black, 14% Hispanic) completed 2 grids and up to 6 unannounced, telephone, interviewer-administered DRs over 1 year. Spearman correlations (ρ; 95% CIs) were calculated to assess reproducibility between the repeated eating-occasion grid-derived variables (e.g., numbers of snacks and meals per day, timing of eating occasions) and to assess relative validity by comparing the meal grid and DR-derived summary data separately for weekdays and weekend days.

RESULTS

Reproducibility correlations for eating-occasion variables derived from the eating-occasion grids completed 1 year apart were ≥0.5 for the majority of variables analyzed for both weekdays and weekend days, including numbers of snacks and meals per day and timing of the first and last eating occasions of the day. Relative validity was highest among weekday variables and was ≥0.5 for the majority of variables, with correlations ranging from ρ values of 0.32 (number of meals per day) to 0.68 (hour of the first eating occasion).

CONCLUSIONS

These findings suggest the eating-occasion grid used in CPS-3 has good reproducibility over 1 year and yields estimates comparable to those from a more detailed method of assessment of eating timing and frequency.

Sugar-sweetened beverage consumption and weight gain in children and adults: a systematic review and meta-analysis of prospective cohort studies and randomized controlled trials

BACKGROUND

Sugar-sweetened beverages (SSBs) have been implicated in fueling the obesity epidemic.

OBJECTIVES

This study aimed to update a synthesis of the evidence on SSBs and weight gain in children and adults.

METHODS

MEDLINE, Embase, and Cochrane databases were searched through September 8, 2022, for prospective cohort studies and randomized controlled trials (RCTs) that evaluated intake of SSBs in relation to BMI and body weight in children and adults, respectively. Eligible interventions were compared against a noncaloric control. Study-level estimates were pooled using random-effects meta-analysis and presented as β-coefficients with 95% CIs for cohorts and weighted mean differences (MDs) with 95% CIs for RCTs.

RESULTS

We identified 85 articles including 48 in children (40 cohorts, n = 91,713; 8 RCTs, n = 2783) and 37 in adults (21 cohorts, n = 448,661; 16 RCTs, n = 1343). Among cohort studies, each serving/day increase in SSB intake was associated with a 0.07-kg/m² (95% CI: 0.04 kg/m², 0.10 kg/m²) higher BMI in children and a 0.42-kg (95% CI: 0.26 kg, 0.58 kg) higher body weight in adults. RCTs in children indicated less BMI gain with SSB reduction interventions compared with control (MD: -0.21 kg/m²; 95% CI: -0.40 kg/m², -0.01 kg/m²). In adults, randomization to addition of SSBs to the diet led to greater body weight gain (MD: 0.83 kg; 95% CI: 0.47 kg, 1.19 kg), and subtraction of SSBs led to weight loss (MD: -0.49 kg; 95% CI: -0.66 kg, -0.32 kg) compared with the control groups. A positive linear dose-response association between SSB consumption and weight gain was found in all outcomes assessed.

CONCLUSIONS

Our updated systematic review and meta-analysis expands on prior evidence to confirm that SSB consumption promotes higher BMI and body weight in both children and adults, underscoring the importance of dietary guidance and public policy strategies to limit intake. This meta-analysis was registered at the International Prospective Register of Systematic Reviews as CRD42020209915.

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.

Important Food Sources of Fructose-Containing Sugars and Non-Alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis of Controlled Trials

Background: Fructose providing excess calories in the form of sugar sweetened beverages (SSBs) increases markers of non-alcoholic fatty liver disease (NAFLD). Whether this effect holds for other important food sources of fructose-containing sugars is unclear. To investigate the role of food source and energy, we conducted a systematic review and meta-analysis of controlled trials of the effect of fructose-containing sugars by food source at different levels of energy control on non-alcoholic fatty liver disease (NAFLD) markers. Methods and Findings: MEDLINE, Embase, and the Cochrane Library were searched through 7 January 2022 for controlled trials ≥7-days. Four trial designs were prespecified: substitution (energy-matched substitution of sugars for other macronutrients); addition (excess energy from sugars added to diets); subtraction (excess energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced by other macronutrients). The primary outcome was intrahepatocellular lipid (IHCL). Secondary outcomes were alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Independent reviewers extracted data and assessed risk of bias. The certainty of evidence was assessed using GRADE. We included 51 trials (75 trial comparisons, n = 2059) of 10 food sources (sugar-sweetened beverages (SSBs); sweetened dairy alternative; 100% fruit juice; fruit; dried fruit; mixed fruit sources; sweets and desserts; added nutritive sweetener; honey; and mixed sources (with SSBs)) in predominantly healthy mixed weight or overweight/obese younger adults. Total fructose-containing sugars increased IHCL (standardized mean difference = 1.72 [95% CI, 1.08 to 2.36], p < 0.001) in addition trials and decreased AST in subtraction trials with no effect on any outcome in substitution or ad libitum trials. There was evidence of influence by food source with SSBs increasing IHCL and ALT in addition trials and mixed sources (with SSBs) decreasing AST in subtraction trials. The certainty of evidence was high for the effect on IHCL and moderate for the effect on ALT for SSBs in addition trials, low for the effect on AST for the removal of energy from mixed sources (with SSBs) in subtraction trials, and generally low to moderate for all other comparisons. Conclusions: Energy control and food source appear to mediate the effect of fructose-containing sugars on NAFLD markers. The evidence provides a good indication that the addition of excess energy from SSBs leads to large increases in liver fat and small important increases in ALT while there is less of an indication that the removal of energy from mixed sources (with SSBs) leads to moderate reductions in AST. Varying uncertainty remains for the lack of effect of other important food sources of fructose-containing sugars at different levels of energy control.

Alternate-day fasting, a high-sucrose/caloric diet and praziquantel treatment influence biochemical and behavioral parameters during Schistosoma mansoni infection in male BALB/c mice

Schistosoma mansoni-induced granulomas result in severe damage to the host's liver, as well as neurological and metabolic disorders. We evaluated the biochemical and behavioral changes during schistosomiasis under three diet protocols: ad libitum (AL), alternate-day fasting (ADF) and a high-sucrose/caloric diet (HSD). Healthy male BALB/c mice were divided into noninfected, matched infected and infected/treated [praziquantel (PZQ)] groups. Caloric intake and energy efficiency coefficients associated with diets were measured. Behavioral (exploratory and locomotor) and biochemical (glucose, triglycerides, total cholesterol, AST, ALT, ALP, and γ-GT) tests and histological analysis were performed. Fifteen weeks postinfection, HSD and PZQ promoted weight gain, with higher caloric consumption than ADF (p < 0.05), reflecting serum glucose levels and lipid profiles. HSD and PZQ prevented liver dysfunction (AST and ALT) and significantly prevented increases in granuloma area (p < 0.05). HSD and PZQ also significantly improved mouse physical performance in exploratory and locomotor behavior (p < 0.05), reversing the impaired motivation caused by infection. These findings showed that ADF worsened the course of S. mansoni infection, while HSD and PZQ, even with synergistic effects, prevented and/or attenuated biochemical and behavioral impairment from infection.

Fatty Hepatocytes Induce Skeletal Muscle Atrophy In Vitro: A New 3D Platform to Study the Protective Effect of Albumin in Non-Alcoholic Fatty Liver

The liver neutralizes endogenous and exogenous toxins and metabolites, being metabolically interconnected with many organs. Numerous clinical and experimental studies show a strong association between Non-alcoholic fatty liver disease (NAFLD) and loss of skeletal muscle mass known as sarcopenia. Liver transplantation solves the hepatic-related insufficiencies, but it is unable to revert sarcopenia. Knowing the mechanism(s) by which different organs communicate with each other is crucial to improve the drug development that still relies on the two-dimensional models. However, those models fail to mimic the pathological features of the disease. Here, both liver and skeletal muscle cells were encapsulated in gelatin methacryloyl and carboxymethylcellulose to recreate the disease’s phenotype in vitro. The 3D hepatocytes were challenged with non-esterified fatty acids (NEFAs) inducing features of Non-alcoholic fatty liver (NAFL) such as lipid accumulation, metabolic activity impairment and apoptosis. The 3D skeletal muscle tissues incubated with supernatant from fatty hepatocytes displayed loss of maturation and atrophy. This study demonstrates the connection between the liver and the skeletal muscle in NAFL, narrowing down the players for potential treatments. The tool herein presented was employed as a customizable 3D in vitro platform to assess the protective effect of albumin on both hepatocytes and myotubes.

Empirically derived dietary pattern and odds of non-alcoholic fatty liver diseases in overweight and obese adults: a case-control study

Background

The prevalence of non-alcoholic fatty liver disease (NAFLD) is rising at an exponential rate throughout the world. Given the confirmed association between nutritional status and NAFLD, this study aimed to investigate the relationship of dietary patterns with NAFLD in overweight and obese adults.

Methods

In this age- and gender-matched case–control study, 115 newly diagnosed cases and 102 control individuals participated. A validated 178-item semi-quantitative food frequency questionnaire was administered to assess the participants' dietary data. Dietary patterns were extracted from 24 predefined food groups by factor analysis. Multivariate logistic regression was run to evaluate the relationship between dietary patterns and NAFLD.

Results

Factor analysis resulted in: “western”, “traditional”, and “snack and sweets” dietary patterns. The NAFLD odds were greater in participants at the highest quintile of the “western” dietary pattern than the lowest quintile (OR: 3.52; 95% CI: 1.64, 8.61). A significant increasing trend was observed in NAFLD odds across increasing quintiles of the “western” dietary pattern (P-trend = 0.01). After adjusting for the potential confounders, this relationship remained significant (OR: 3.30; 95% CI: 1.06–10.27). After full adjustments, NAFLD had no association with “traditional” or “snack and sweets” dietary patterns.

Conclusion

The “western” dietary pattern containing fast food, refined grains, liquid oil, pickles, high-fat dairy, sweet desserts, red meat, tea, and coffee was associated with increased odds of NAFLD. However, further prospective studies are required to establish these results.

Nonalcoholic fatty liver disease: lifestyle and quality of life

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder whose current rapidly expanding prevalence is causing it to develop into a major global health concern. NAFLD is closely linked to the modern, unhealthy lifestyle. The Western diet, characterized by excessive energy intake, frequent consumption of red meat, processed meat and foods, soft drinks, and sugar-sweetened beverages (SSBs), irregular meal distribution throughout the day, and unhealthy ways of cooking, predisposes to development of NAFLD. Low levels of physical activity and prolonged sedentary time are additional lifestyle risk factors for NAFLD. Given the present lack of effective pharmacological treatment, lifestyle modifications are regarded as the cornerstone of NAFLD management. Reducing daily calorie intake together with following the Mediterranean diet (MD) is an increasingly accepted approach. Furthermore, increasing the level of physical activity and limiting sedentary behavior are additional measures proposed to improve the outcomes of the disease. Apart from being affected by lifestyle, NAFLD may also affect patients' quality of life (QoL), mostly in the domain of physical function. In this regard, while the early and more benign form of the disease, i.e., simple hepatic steatosis, may not affect QoL, there is evidence, though conflicting, of the impact of nonalcoholic steatohepatitis (NASH) on this index, with, however, most studies showing that QoL is consistently affected in advanced disease, i.e., hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. Considering all the above, appropriate management of lifestyle is likely to attenuate the severity of the disease and improve the QoL of NAFLD patients.

Systematic Review and Meta-Analysis on the Effect of Portion Size and Ingestive Frequency on Energy Intake and Body Weight among Adults in Randomized Controlled Feeding Trials

Energy intake is the product of portion size (PS)-the energy content of an ingestive event-and ingestive frequency (IF)-the number of ingestive events per unit time. An uncompensated alteration in either PS or IF would result in a change in energy intake and body weight if maintained over time. The objective of this meta-analysis was to assess the independent effects of PS and IF on energy intake and body weight among healthy adults in randomized controlled trials (RCTs). A total of 9708 articles were identified in PubMed, Web of Science, Cochrane, and CINAHL databases. The articles were divided among 10 researchers; each article was screened for eligibility by 2-3 independent reviewers. Exclusion criteria included: populations <19 y and >65 y, unhealthy populations (i.e. participants with an acute or chronic disease), assessments <24 h and <4 wk in duration for trials investigating energy intake or body weight, respectively. Controlled feeding trials (i.e. fixed energy intake) that manipulated IF and PS in the same study intervention (IF/PS) were evaluated separately and for the body weight outcome only. Twenty-two studies (IF = 4, PS = 14, IF/PS = 4) met the inclusion criteria. There was an insufficient number of studies to assess the effect of IF, PS, or IF/PS on body weight. There was heterogeneity in the effect sizes among all comparisons (I2 ≥75%). Consuming larger portion sizes was associated with higher daily energy intake [295 kcal (202, 388), n = 24; weighted mean differences (WMD) (95% CI), n = comparisons], and increased frequency of ingestive events was associated with higher energy intake [203 kcal (76, 330), n = 10]. Results from RCTs support that larger PS and greater IF are both associated with higher energy consumption. However, there is insufficient information to determine chronic effects on body weight. This protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018104757.

Clinical practice advice on lifestyle modification in the management of nonalcoholic fatty liver disease in Japan: an expert review

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver diseases worldwide, including in Japan. The Japanese Society of Gastroenterology (JSGE) and the Japanese Society of Hepatology (JSH) have established the Japanese NAFLD/NASH guidelines in 2014 and revised these guidelines in 2020. As described in these guidelines, weight reduction by diet and/or exercise therapy is important for the treatment of NAFLD patients. The I148M single nucleotide polymorphism (rs738409 C > G) of PNPLA3 (patatin-like phospholipase domain-containing 3 protein) is widely known to be associated with the occurrence and progression of NAFLD. In the Japanese, the ratio of PNPLA3 gene polymorphisms found is approximately 20%, which is higher than that found in Westerners. In addition, the ratio of lean NAFLD patients is also higher in Japan than in Western countries. Therefore, the method for lifestyle guidance for the NAFLD patients in Japan would be different from that for the people in Western countries. The problems in the treatment of NAFLD patients include alcohol consumption and sarcopenia. Therefore, guidelines that can help clinicians treat Japanese patients with NAFLD are needed. In this expert review, we summarize evidence-based interventions for lifestyle modification (diet, exercise, alcohol, and sarcopenia) for the treatment of patients with NAFLD, especially from Japan and Asian countries.

A Step Closer to the "Fourth 90": A Practical Narrative Review of Diagnosis and Management of Nutritional Issues of People Living with HIV

The quality of life of people living with HIV (PLWH) has remarkably increased thanks to the introduction of combined antiretroviral therapy. Still, PLWH are exposed to an increased risk of cardiovascular diseases, diabetes, chronic kidney disease, and liver disease. Hence, the purpose of this review is to summarize the current knowledge about diagnosis and nutritional management with specific indication of macro and micronutrients intake for the main comorbidities of PLWH. In fact, a prompt diagnosis and management of lifestyle behaviors are fundamental steps to reach the "fourth 90". To achieve an early diagnosis of these comorbidities, clinicians have at their disposal algorithms such as the Framingham Score to assess cardiovascular risk; transient elastography and liver biopsy to detect NAFLD and NASH; and markers such as the oral glucose tolerance test and GFR to identify glucose impairment and renal failure, respectively. Furthermore, maintenance of ideal body weight is the goal for reducing cardiovascular risk and to improve diabetes, steatosis and fibrosis; while Mediterranean and low-carbohydrate diets are the dietetic approaches proposed for cardioprotective effects and for glycemic control, respectively. Conversely, diet management of chronic kidney disease requires different nutritional assessment, especially regarding protein intake, according to disease stage and eventually concomitant diabetes.

Nonalcoholic fatty liver disease (NAFLD) from pathogenesis to treatment concepts in humans

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) comprises hepatic alterations with increased lipid accumulation (steatosis) without or with inflammation (nonalcoholic steatohepatitis, NASH) and/or fibrosis in the absence of other causes of liver disease. NAFLD is developing as a burgeoning health challenge, mainly due to the worldwide obesity and diabetes epidemics.

SCOPE OF REVIEW

This review summarizes the knowledge on the pathogenesis underlying NAFLD by focusing on studies in humans and on hypercaloric nutrition, including effects of saturated fat and fructose, as well as adipose tissue dysfunction, leading to hepatic lipotoxicity, abnormal mitochondrial function, and oxidative stress, and highlights intestinal dysbiosis. These mechanisms are discussed in the context of current treatments targeting metabolic pathways and the results of related clinical trials.

MAJOR CONCLUSIONS

Recent studies have provided evidence that certain conditions, for example, the severe insulin-resistant diabetes (SIRD) subgroup (cluster) and the presence of an increasing number of gene variants, seem to predispose for excessive risk of NAFLD and its accelerated progression. Recent clinical trials have been frequently unsuccessful in halting or preventing NAFLD progression, perhaps partly due to including unselected cohorts in later stages of NAFLD. On the basis of this literature review, this study proposed screening in individuals with the highest genetic or acquired risk of disease progression, for example, the SIRD subgroup, and developing treatment concepts targeting the earliest pathophysiolgical alterations, namely, adipocyte dysfunction and insulin resistance.

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).

Dietary Interventions in Liver Diseases: Focus on MAFLD and Cirrhosis

Purpose of Review

Dietary interventions (DI) aimed at improving overweight and metabolic abnormalities in metabolic dysfunction-associated fatty liver disease (MAFLD) and at reducing malnutrition and sarcopenia in cirrhosis should become part of routine care in hepatology. This review focuses on recent advances in this field.

Recent Findings

In patients with MAFLD, a gradual reduction, respectively, of 7–10% of body weight if overweight or of 3–5% if lean, obtained by moderately reducing caloric intake, is effective to improve liver disease. Intermittent energy restriction might be an alternative to continuous energy restriction with higher adherence. Qualitative dietary adjustments should include increased intake of unprocessed foods including fruits and vegetables, whole grains, fiber, and unsaturated fatty acids (FAs), for example, through a Mediterranean diet. Refined carbohydrates (CHOs), saturated FA (SFAs), red meat, and processed meat should be limited. DI studies in HIV-infected subjects with MAFLD are very limited, and this is a field for future research. In patients with cirrhosis, DI should aim at correcting malnutrition and improving skeletal muscle mass. Daily diet contents should aim at achieving 30–35 kcal/kg of body weight, including 1.2–1.5 g/kg proteins, and oral or enteral supplementation might be used in patients unable to achieve these targets. In some studies, branched-chain amino acids (BCAAs) proved to be effective in improving muscle mass and were associated with a lower risk of hepatic encephalopathy. Obesity requires adjustment of the above-mentioned targets, and its management is challenging. Studies looking at the efficacy of DI recommended by the existing guidelines on clinical endpoints are a field for future research.

Summary

Dietary interventions are able to improve MAFLD and show potential to reduce complications in liver disease. Despite its key importance, there are many barriers limiting the implementation of DI in patients with chronic liver disease. Patients’ empowerment is crucial and should be the focus of specific educational programs. In addition, liver clinics would benefit from multidisciplinary teams involving experts in nutrition, physical exercise, primary care physicians, and psychologists when needed.

The Role of Fructose in Non-Alcoholic Steatohepatitis: Old Relationship and New Insights

Non-alcoholic fatty liver disease (NAFLD) represents the result of hepatic fat overload not due to alcohol consumption and potentially evolving to advanced fibrosis, cirrhosis, and hepatocellular carcinoma. Fructose is a naturally occurring simple sugar widely used in food industry linked to glucose to form sucrose, largely contained in hypercaloric food and beverages. An increasing amount of evidence in scientific literature highlighted a detrimental effect of dietary fructose consumption on metabolic disorders such as insulin resistance, obesity, hepatic steatosis, and NAFLD-related fibrosis as well. An excessive fructose consumption has been associated with NAFLD development and progression to more clinically severe phenotypes by exerting various toxic effects, including increased fatty acid production, oxidative stress, and worsening insulin resistance. Furthermore, some studies in this context demonstrated even a crucial role in liver cancer progression. Despite this compelling evidence, the molecular mechanisms by which fructose elicits those effects on liver metabolism remain unclear. Emerging data suggest that dietary fructose may directly alter the expression of genes involved in lipid metabolism, including those that increase hepatic fat accumulation or reduce hepatic fat removal. This review aimed to summarize the current understanding of fructose metabolism on NAFLD pathogenesis and progression.

Improving insulin sensitivity, liver steatosis and fibrosis in type 2 diabetes by a food-based digital education-assisted lifestyle intervention program: a feasibility study

PURPOSE

Recent trials demonstrated remission of type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) following formula diet-induced weight loss. To improve the outreach for populations in need, many mobile health apps targeting weight loss have been developed with limited scientific evaluation of these apps. The present feasibility study investigated the effects of a novel approach incorporating a regular 'whole food-based' low-calorie diet combined with app-based digital education and behavioral change program on glucose metabolism and disease management.

METHODS

Twenty-four individuals with type 2 diabetes followed this approach supported by weekly coaching calls for 12 weeks. Phenotyping included bioimpedance analysis, mixed-meal tolerance test, magnetic resonance spectroscopy and transient elastography for assessing liver fat content and liver stiffness.

RESULTS

Over 12 weeks, participants reduced their body weight by 9% (97 ± 13 to 88 ± 12 kg), body mass index (BMI; 33 ± 5 to 29 ± 4 kg/m²), total fat mass (31 ± 10 to 27 ± 10%) (all p < 0.01) and liver fat by 50% alongside with decreased liver stiffness. Target HbA1c (< 6.5%) was achieved by 38% and resolution of NAFLD (liver fat content < 5.6%) was observed in 30% of the participants.

CONCLUSION

This novel approach combining digital education with a low-calorie diet results in effective improvements of body weight, glycemic control and NAFLD and could complement existing care for patients with type 2 diabetes.

TRIAL REGISTRATION

NCT04509245.

Dietary Patterns with Healthy and Unhealthy Traits Among Overweight/Obese Hispanic Women with or at High Risk for Type 2 Diabetes

Hispanic women are at high risk for type 2 diabetes (T2D), with obesity and unhealthy eating being important contributing factors. A cross-sectional design was used in this study to identify dietary patterns and their associations with diabetes risk factors. Participants completed a culturally adapted Food Frequency Questionnaire capturing intake over the prior 3 months. Overweight/obese Hispanic women (n = 191) with or at risk for T2D were recruited from a community clinic into a weight loss intervention. Only baseline data was used for this analysis. Dietary patterns and their association with diabetes risk factors (age, body mass index, abdominal obesity, elevated fasting blood glucose [FBG], and hemoglobin A1c). An exploratory factor analysis of dietary data adjusted for energy intake was used to identify eating patterns, and Pearson correlation coefficient (r) to assess the association of the eating patterns with the diabetes risk factors. Six meaningful patterns with healthful and unhealthful traits emerged: (1) sugar and fat-laden, (2) plant foods and fish, (3) soups and starchy dishes, (4) meats and snacks, (5) beans and grains, and (6) eggs and dairy. Scores for the "sugar and fat-laden" and "meats and snacks" patterns were negatively associated with age (r = - 0.230, p = 0.001 and r = - 0.298, p < 0.001, respectively). Scores for "plant foods and fish" were positively associated with FBG (r = 0.152, p = 0.037). Being younger may be an important risk factor for a diet rich in sugar and fat; this highlights the need to assess dietary patterns among younger Hispanic women to identify traits potentially detrimental for their health.

Diversity in NAFLD: A Review of Manifestations of Nonalcoholic Fatty Liver Disease in Different Ethnicities Globally

Globally, the rise in prevalence of obesity and metabolic syndrome as a whole has been linked to increased access to processed foods, such as refined sugars and saturated fats. Consequently, nonalcoholic fatty liver disease (NAFLD) is on the rise in both developed and developing nations. However, much is still unknown on the NAFLD phenotype with regards to the effect of ethnic diversity. Despite similarities in dietary habits, it appears that certain ethnicities are more protected against NAFLD than others. However, manifestations of the same genetic polymorphisms in different groups of people increase those individuals' predisposition to NAFLD. Diets from different regions have been associated with a lower prevalence of NAFLD and have even been linked to regression of hepatic steatosis. Socioeconomic variations amongst different regions of the world also contribute to NAFLD prevalence and associated complications. Thus, a thorough understanding of ethnic variability in NAFLD is essential to tailoring treatment recommendations to patients of different backgrounds.

The Impact of Macronutrient Intake on Non-alcoholic Fatty Liver Disease (NAFLD): Too Much Fat, Too Much Carbohydrate, or Just Too Many Calories?

Non-alcoholic fatty liver disease (NAFLD) is a growing epidemic, in parallel with the obesity crisis, rapidly becoming one of the commonest causes of chronic liver disease worldwide. Diet and physical activity are important determinants of liver fat accumulation related to insulin resistance, dysfunctional adipose tissue, and secondary impaired lipid storage and/or increased lipolysis. While it is evident that a hypercaloric diet (an overconsumption of calories) promotes liver fat accumulation, it is also clear that the macronutrient composition can modulate this risk. A number of other baseline factors modify the overfeeding response, which may be genetic or environmental. Although it is difficult to disentangle the effects of excess calories vs. specifically the individual effects of excessive carbohydrates and/or fats, isocaloric, and hypercaloric dietary intervention studies have been implemented to provide insight into the effects of different macronutrients, sub-types and their relative balance, on the regulation of liver fat. What has emerged is that different types of fat and carbohydrates differentially influence liver fat accumulation, even when diets are isocaloric. Furthermore, distinct molecular and metabolic pathways mediate the effects of carbohydrates and fat intake on hepatic steatosis. Fat accumulation appears to act through impairments in lipid storage and/or increased lipolysis, whereas carbohydrate consumption has been shown to promote liver fat accumulation through de novo lipogenesis. Effects differ dependent upon carbohydrate and fat type. Saturated fat and fructose induce the greatest increase in intrahepatic triglycerides (IHTG), insulin resistance, and harmful ceramides compared with unsaturated fats, which have been found to be protective. Decreased intake of saturated fats and avoidance of added sugars are therefore the two most important dietary interventions that can lead to a reduction in IHTG and potentially the associated risk of developing type 2 diabetes. A healthy and balanced diet and regular physical activity must remain the cornerstones of effective lifestyle intervention to prevent the development and progression of NAFLD. Considering the sub-type of each macronutrient, in addition to the quantity, are critical determinants of liver health.

Insights into the Impact of Microbiota in the Treatment of NAFLD/NASH and Its Potential as a Biomarker for Prognosis and Diagnosis

Non-alcoholic fatty liver disease (NAFLD) is an increasing cause of chronic liver illness associated with obesity and metabolic disorders, such as hypertension, dyslipidemia, or type 2 diabetes mellitus. A more severe type of NAFLD, non-alcoholic steatohepatitis (NASH), is considered an ongoing global health threat and dramatically increases the risks of cirrhosis, liver failure, and hepatocellular carcinoma. Several reports have demonstrated that liver steatosis is associated with the elevation of certain clinical and biochemical markers but with low predictive potential. In addition, current imaging methods are inaccurate and inadequate for quantification of liver steatosis and do not distinguish clearly between the microvesicular and the macrovesicular types. On the other hand, an unhealthy status usually presents an altered gut microbiota, associated with the loss of its functions. Indeed, NAFLD pathophysiology has been linked to lower microbial diversity and a weakened intestinal barrier, exposing the host to bacterial components and stimulating pathways of immune defense and inflammation via toll-like receptor signaling. Moreover, this activation of inflammation in hepatocytes induces progression from simple steatosis to NASH. In the present review, we aim to: (a) summarize studies on both human and animals addressed to determine the impact of alterations in gut microbiota in NASH; (b) evaluate the potential role of such alterations as biomarkers for prognosis and diagnosis of this disorder; and (c) discuss the involvement of microbiota in the current treatment for NAFLD/NASH (i.e., bariatric surgery, physical exercise and lifestyle, diet, probiotics and prebiotics, and fecal microbiota transplantation).

The effect of meal frequency on biochemical cardiometabolic factors: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Although several randomized controlled trials (RCTs) have supported the beneficial effects of higher meal frequency (MF) on cardiometabolic risk factors, the putative effects of higher MF on health remain inconclusive. This study systematically reviewed the evidence from RCTs of the effect of higher compared with lower MF on the blood lipid profile, glucose homeostasis, and adipokines.

METHODS

PubMed, Scopus, ISI Web of Science, and the Cochrane database were searched up to October 2020 to retrieve relevant RCTs. A DerSimonian and Laird random effects model was used to pool mean differences and 95% CI for each outcome. The quality of studies and evidence was assessed through standard methods.

RESULTS

Twenty-one RCTs (686 participants) were included in this meta-analysis. Overall results showed a significant improvement in total cholesterol [weighted mean difference (WMD) = -6.08 mg/dl; 95% CI: -10.68, -1.48; P = 0.01; I² = 88%], and low-density cholesterol (LDL-C) (WMD = -6.82 mg/dl; 95% CI: -10.97, -1.60; P = 0.009; I² = 85.7%), while LDL-C to high-density cholesterol ratio (LDL-C: HDL-C) increased (WMD = 0.22; 95% CI: 0.07, 0.36; P = 0.003; I² = 0.0%) in higher MF vs. lower MF. No significant effects were found on measures of glycemic control, apolipoproteins-A1 and B, or leptin. In subgroup analyses, higher MF significantly reduced serum triglyceride (TG), and increased HDL-C, compared with lower MF in interventions > 12 weeks, and decreased serum TC and LDL-C in healthy participants. A significant reduction in LDL-C also was observed in studies where the same foods given both arms, simply divided into different feeding occasions, and in feeding studies, following higher MF compared to lower MF.

CONCLUSION

Our meta-analysis found that higher, compared with lower MF may improve total cholesterol, and LDL-C. The intervention does not affect measures of glycemic control, apolipoproteins-A1 and B, or leptin. However, the GRADE ratings of low credibility of the currently available evidence highlights the need for more high-quality studies in order to reach a firm conclusion.

Infusion of donor feces affects the gut-brain axis in humans with metabolic syndrome

OBJECTIVE

Increasing evidence indicates that intestinal microbiota play a role in diverse metabolic processes via intestinal butyrate production. Human bariatric surgery data suggest that the gut-brain axis is also involved in this process, but the underlying mechanisms remain unknown.

METHODS

We compared the effect of fecal microbiota transfer (FMT) from post-Roux-en-Y gastric bypass (RYGB) donors vs oral butyrate supplementation on (123I-FP-CIT-determined) brain dopamine transporter (DAT) and serotonin transporter (SERT) binding as well as stable isotope-determined insulin sensitivity at baseline and after 4 weeks in 24 male and female treatment-naïve metabolic syndrome subjects. Plasma metabolites and fecal microbiota were also determined at these time points.

RESULTS

We observed an increase in brain DAT after donor FMT compared to oral butyrate that reduced this binding. However, no effect on body weight and insulin sensitivity was demonstrated after post-RYGB donor feces transfer in humans with metabolic syndrome. Increases in fecal levels of Bacteroides uniformis were significantly associated with an increase in DAT, whereas increases in Prevotella spp. showed an inverse association. Changes in the plasma metabolites glycine, betaine, methionine, and lysine (associated with the S-adenosylmethionine cycle) were also associated with altered striatal DAT expression.

CONCLUSIONS

Although more and larger studies are needed, our data suggest a potential gut microbiota-driven modulation of brain dopamine and serotonin transporters in human subjects with obese metabolic syndrome. These data also suggest the presence of a gut-brain axis in humans that can be modulated.

NTR REGISTRATION

4488.

Nutrients, Genetic Factors, and Their Interaction in Non-Alcoholic Fatty Liver Disease and Cardiovascular Disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western countries and expose patients to increased risk of hepatic and cardiovascular (CV) morbidity and mortality. Both environmental factors and genetic predisposition contribute to the risk. An inappropriate diet, rich in refined carbohydrates, especially fructose, and saturated fats, and poor in fibers, polyunsaturated fats, and vitamins is one of the main key factors, as well as the polymorphism of patatin-like phospholipase domain containing 3 (PNPLA3 gene) for NAFLD and the apolipoproteins and the peroxisome proliferator-activated receptor (PPAR) family for the cardiovascular damage. Beyond genetic influence, also epigenetics modifications are responsible for various clinical manifestations of both hepatic and CV disease. Interestingly, data are accumulating on the interplay between diet and genetic and epigenetic modifications, modulating pathogenetic pathways in NAFLD and CV disease. We report the main evidence from literature on the influence of both macro and micronutrients in NAFLD and CV damage and the role of genetics either alone or combined with diet in increasing the risk of developing both diseases. Understanding the interaction between metabolic alterations, genetics and diet are essential to treat the diseases and tailoring nutritional therapy to control NAFLD and CV risk.

Organismal Fructose Metabolism in Health and Non-Alcoholic Fatty Liver Disease

NAFLD has alarmingly increased, yet FDA-approved drugs are still lacking. An excessive intake of fructose, especially in liquid form, is a dietary risk factor of NAFLD. While fructose metabolism has been studied for decades, it is still controversial how fructose intake can cause NAFLD. It has long been believed that fructose metabolism solely happens in the liver and accordingly, numerous studies have investigated liver fructose metabolism using primary hepatocytes or liver cell lines in culture. While cultured cells are useful for studying detailed signaling pathways and metabolism in a cell-autonomous manner, it is equally important to understand fructose metabolism at the whole-body level in live organisms. In this regard, recent in vivo studies using genetically modified mice and stable isotope tracing have tremendously expanded our understanding of the complex interaction between fructose-catabolizing organs and gut microbiota. Here, we discuss how the aberrant distribution of fructose metabolism between organs and gut microbiota can contribute to NAFLD. We also address potential therapeutic interventions of fructose-elicited NAFLD.

EZH2 as a Potential Target for NAFLD Therapy

Non-alcoholic fatty liver disease (NAFLD) is a complex disease that is affected by genetic predisposition and epigenetic modification. Deregulation of epigenetic pathways is now recognized as a frequent event in NAFLD, and understanding the mechanistic roles of these epigenetic factors may lead to new strategies for NAFLD treatment. Enhancer of zeste homolog 2 (EZH2) catalyzes methylation on Lys 27 of histone H3, which leads to chromatin compaction and gene silencing. EZH2 regulates embryonic development and cell lineage determination and is related to many human diseases. Recent studies show that EZH2 has critical roles in liver development, homeostasis, and regeneration. Moreover, aberrant activation of EZH2 promotes NAFLD progression. Several EZH2 inhibitors have been developed and studied both in vitro and in clinical trials. In this review, we summarize our current understanding of the role of EZH2 in NAFLD and highlight its potential as a novel therapeutic target for NAFLD treatment.

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

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

Lifestyle interventions affecting hepatic fatty acid metabolism

PURPOSE OF REVIEW

Prevalence of metabolic-associated fatty liver disease (MAFLD) is increasing, and as pharmacological treatment does not exist, lifestyle interventions (i.e. diet and exercise) represent the cornerstone management and treatment strategy. Although the available data clearly demonstrate that changes in lifestyle influence intrahepatic triglyceride (IHTG) content, the mechanisms through which this is achieved are seldom investigated. Here, we review recent evidence demonstrating the influence of lifestyle interventions on hepatic fatty acid metabolism and IHTG content.

RECENT FINDINGS

Diet and exercise influence IHTG content through various, and often interrelated factors. These include alterations in whole-body and tissue-specific insulin sensitivity, which may influence the flux of fatty acid and lipogenic substrates to the liver, and changes in intrahepatic fatty acid synthesis and partitioning. Notably, there are only a few studies that have investigated intrahepatic fatty acid metabolism in vivo in humans before and after an intervention.

SUMMARY

Lifestyle interventions represent an effective means of influencing hepatic fatty acid metabolism. IHTG content is decreased without weight-loss either through exercise or by changing the macronutrient composition of the diet, although what the optimal macronutrient composition is to achieve this has yet to be defined.