Intermittent fasting and protein pacing are superior to caloric restriction for weight and visceral fat loss

Lipid droplets: Emerging therapeutic targets for age-related metabolic diseases

Lipids metabolism is crucial in regulating aging and metabolic diseases. Lipid droplets (LDs) are dynamic, complex organelles responsible for the storage and release of neutral lipids, essential for maintaining lipid homeostasis and energy metabolism. Aging accelerates the accumulation of LDs, functional deterioration, and metabolic disorders, thereby inducing age-related metabolic diseases (ARMDs). This review examines published datasets on the association between LDs and ARMDs, focusing on the structure and function of LDs, their interactions with other organelles, and associated proteins. Furthermore, we explore the potential mechanisms by which LDs mediate the onset of ARMDs, including Alzheimer's disease (AD), sarcopenia, metabolic cardiomyopathy, non-alcoholic fatty liver disease (NAFLD), and cancer. Lastly, we discuss intervention strategies aimed at targeting LDs to improve outcomes in ARMDs, including exercise, dietary, and pharmacological interventions.

From Soil to Brain: Olive Oil Attributes, Consumer Choices, Intermittent Fasting, and Their Impact on Health

Olive oil (OO) has longstanding significance in human history, particularly in the Mediterranean region, where it has been a cornerstone of diet, economy, and culture. This history adds to modern evidence-based knowledge. Background: The Mediterranean diet (MD), rich in plant-based foods and OO, has been extensively associated with improved cardiometabolic and cognitive health. Recent interest has emerged in understanding how intermittent fasting protocols may enhance these effects. Still, the quality of OO does not only lie in the extraction process; it is also dependent on the tree variety, the soil, and the agricultural practices, ending with the way in which the finished product is stored and consumed. Objectives: This review explores the synergistic potential between OO consumption and intermittent fasting, focusing on their combined impact on metabolic health, oxidative stress, and inflammatory pathways. Methods: A literature search was conducted using multiple databases to identify studies addressing the health effects of OO, fasting, and the MD. Both human and relevant preclinical studies were considered, with emphasis on those evaluating inflammatory markers, lipid metabolism, insulin sensitivity, and neuroprotective mechanisms. Results: Evidence suggests that the bioactive compounds in EVOO may potentiate the benefits of fasting by enhancing antioxidant capacity, reducing postprandial inflammation, and modulating gene expression related to cellular metabolism. Combined, these factors may support improved insulin sensitivity, reduced oxidative damage, and delayed onset of age-related diseases. Conclusions: Understanding the integrative role of OO and fasting within the MD framework could offer valuable insights for nutritional strategies aimed at preventing metabolic syndrome, type 2 diabetes, and neurodegeneration. These findings also support the need for future clinical trials exploring the timing, dosage, and dietary context in which these interventions are most effective.

Effects of induced molting on lipid accumulation in liver of aged laying hens

As the age of laying increases, the metabolic capacity of the liver decreases, leading to excessive lipid accumulation, which seriously affects the laying performance of laying hens. Induced molting (IM) can rejuvenate the reproductive system of older laying hens, allowing them to enter a new laying cycle. However, it remains unclear whether induced molting can enhance lipid accumulation in the liver of aged laying hens and what the underlying mechanism might be. In this study, fasting-induced molting was performed on 70-week-old Hy-line brown laying hens, and the resulting metabolic changes were analyzed using non-targeted metabolomics. Serum lipid levels, liver oxidative stress, and inflammation were measured using kits, while autophagy and lipid metabolism-related factors were assessed through immunofluorescence and western blotting. The results showed that IM could promote hepatic lipid deposition in aged laying hens, reduce hepatic steatosis and injury, lower the blood lipid level, improve hepatic antioxidant capacity and increase egg production rate. During the fasting period, the hepatic autophagic system was activated in laying hens and the level of hepatic autophagy increased. Additionally, AMPK phosphorylation levels increased, while the expression of fatty acid synthesis genes SREBP-1C, ACC, and FASN decreased (P < 0.01). The expression of PPARα, PGC 1α and CPT1A, which are associated with fatty acid oxidation, was upregulated (P < 0.01). In conclusion, IM enhanced lipid metabolism, increased liver autophagy, and improved liver function in aged laying hens.

Time-restricted feeding improves metabolic syndrome by activating thermogenesis in brown adipose tissue and reducing inflammatory markers

Background

Obesity and metabolic syndrome (MetS) have become increasingly significant global health issues. Time-restricted feeding (TRF), as a novel dietary intervention, has garnered attention in recent years. However, there is limited research focusing on the effects of TRF on energy expenditure and systemic low-grade inflammation. This study aims to investigate the impact of TRF on weight management, glucose metabolism, insulin resistance, and lipid metabolism in male C57BL/6J mice, particularly in the context of metabolic disorders induced by a high-fat diet (HFD).

Methods

C57BL/6J mice were divided into two groups: a normal diet (ND) group and a high-fat diet (HFD) group. The study duration was 12 weeks. Key parameters observed included body weight, glucose tolerance (via glucose tolerance tests), insulin resistance (HOMA-IR), and insulin secretion under glucose stimulation. Additionally, liver tissue was subjected to Oil Red O staining to assess lipid accumulation, and white and brown adipose tissues were stained with hematoxylin and eosin (HE) to evaluate adipocyte size. The expression of hepatic lipogenesis-related genes (Srebp-c, Chrebp, Fasn, and Acc1) and thermogenic genes in brown adipose tissue (UCP1 and PGC-1α) were also measured. Furthermore, temperature changes in the interscapular brown adipose tissue (BAT) were monitored.

Results

In the ND group: TRF improved insulin resistance and reduced circulating levels of the pro-inflammatory cytokine IL-6, with a slight reduction in body weight.In the HFD group: TRF significantly mitigated weight gain, improved glucose tolerance and insulin resistance, and enhanced insulin secretion under glucose stimulation. Additionally, TRF reduced hepatic steatosis by downregulating the expression of lipogenesis-related genes in the liver. TRF also increased thermogenesis by upregulating the expression of thermogenic genes (UCP1 and PGC-1α) in BAT, while lowering serum levels of pro-inflammatory cytokines IL-6 and TNF-α, though IL-1β levels remained unchanged.

Conclusion

This study demonstrates that TRF can activate thermogenesis in brown adipose tissue and reduce inflammation maker, leading to an improvement in hepatic steatosis and a reduction in white adipose tissue accumulation. These findings suggest that TRF may be a promising intervention for mitigating metabolic disturbances associated with obesity and metabolic syndrome. The study provides mechanistic insights into the beneficial effects of TRF, highlighting its potential in modulating lipid metabolism and exerting anti-inflammatory effects.

The Effect of the 14:10-Hour Time-Restricted Feeding (TRF) Regimen on Selected Markers of Glucose Homeostasis in Diet-Induced Prediabetic Male Sprague Dawley Rats

BACKGROUND

Prediabetes is a condition that often precedes the onset of type 2 diabetes mellitus (T2DM). Literature evidence indicates that prediabetes is reversible, making it an important therapeutic target for preventing the progression to T2DM. Several studies have investigated intermittent fasting as a possible method to manage or treat prediabetes.

OBJECTIVES

This study evaluated the impact of a 14:10-hour time-restricted feeding (TRF) regimen on leptin concentration, insulin sensitivity and selected markers associated with the insulin signalling pathway and glucose homeostasis in diet-induced prediabetic rats.

METHODS

Twenty-four male Sprague Dawley rats were obtained and randomly divided into two dietary groups: group 1 (n = 6) received a standard diet and water, while group 2 (n = 18) was provided a high-fat, high-carbohydrate (HFHC) diet supplemented with 15% fructose for a period of 20 weeks to induce prediabetes. After confirming prediabetes, an intermittent fasting (IF) regimen was assigned to the rats while also having untreated and metformin-treated prediabetic rats serving as controls.

RESULTS

Both IF and HFHC-Met groups yield significantly lower blood glucose, leptin and BMI results compared to the prediabetic group. The IF group yielded significantly lower insulin, HOMA-IR and HbA1C than both controls.

CONCLUSIONS

The study showed the potential of IF in alleviating prediabetes-induced dysregulation of glucose homeostasis and therefore warrants further investigations into its use in the management of prediabetes.

Aging, ROS, and cellular senescence: a trilogy in the progression of liver fibrosis

Ageing is an inevitable and multifaceted biological process that impacts a wide range of cellular and molecular mechanisms, leading to the development of various diseases, such as liver fibrosis. Liver fibrosis progresses to cirrhosis, which is an advanced form due to high amounts of extracellular matrix and restoration of normal liver structure with failure to repair damaged tissue and cells, marking the end of liver function and total liver failure, ultimately death. The most important factors are reactive oxygen species (ROS) and cellular senescence. Oxidative stress is defined as an impairment by ROS, which are by-products of the mitochondrial electron transport chain and other key molecular pathways that induce cell damage and can activate cellular senescence pathways. Cellular senescence is characterized by pro-inflammatory cytokines, growth factors, and proteases secreted by senescent cells, collectively known as the senescence-associated secretory phenotype (SASP). The presence of senescent cells, which disrupt tissue architecture and function and increase senescent cell production in liver tissues, contributes to fibrogenesis. Hepatic stellate cells (HSCs) are activated in response to chronic liver injury, oxidative stress, and senescence signals that drive excessive production and deposition of extracellular matrix. This review article aims to provide a comprehensive overview of the pathogenic role of ROS and cellular senescence in the aging liver and their contribution to fibrosis.

Chronic mistimed feeding results in renal fibrosis and disrupted circadian blood pressure rhythms

Circadian disruption is a disturbance in biological timing, which can occur within or between different organizational levels, ranging from molecular rhythms within specific cells to the misalignment of behavioral and environmental cycles. Previous work from our group showed that less than 1 wk of food restriction to the light (inactive) period is sufficient to invert diurnal blood pressure rhythms in mice. However, kidney excretory rhythms and functions remained aligned with the light-dark cycle. Shift workers have an increased risk of cardiovascular disease that may different between sexes and often have irregular mealtimes, making the possibility of mistimed feeding as a potential contributor to the development of kidney disease. Thus, we hypothesized that chronic mistimed food intake would result in adverse cardiorenal effects, with sex differences in severity. Here, we show that chronic circadian disruption via mistimed feeding results in renal fibrosis and aortic stiffness in a sex-dependent manner. Our results indicate the importance of meal timing for the maintenance of blood pressure rhythms and kidney function, particularly in males. Our results also demonstrate that females are better able to acclimate to circadian-related behavioral change. NEW & NOTEWORTHY Circadian disruption through mistimed feeding resulted in nondipping blood pressure, renal fibrosis, and arterial stiffness that were less severe in females versus males. Mice fed exclusively during the daytime maintain their circadian rhythms of locomotor activity regardless of their loss of blood pressure rhythms. Although these mice ate less food, they maintained body weight, suggesting inefficiencies in overall metabolism. These findings demonstrate the importance of maintaining optimal food intake patterns to prevent cardiorenal pathophysiology.

Plant-Based Dietary Protein Is Associated with Lower Metabolic Syndrome Risk in Division III Female Athletes: A Pilot Study

BACKGROUND

College athletes are often overlooked for metabolic syndrome (MetS), as their increased physical activity is assumed to reduce their disease risk. However, energy or macronutrient imbalance has been shown to increase risk independent of activity. The purpose of this investigation was to assess the current dietary habits of Division III female athletes and determine their associations with body composition and MetS. Secondly, we sought to determine whether dietary intake and dietary protein source (i.e., animal- and plant-based, ABP and PBP) and quality were associated with MetS, as estimated by the Simple Method for Quantifying Metabolic Syndrome (siMS) score and the siMS risk score, and whether protein pacing was associated with body composition in Division III female athletes.

METHODS

Stepwise linear regression determined whether age (years), body mass (kg), body mass index (BMI; kg/m2), ABP (g/d), PBP (g/d), ABP:PBP, ratio of high-quality to low-quality ABP (ABP QR), relative energy intake (kcal/kg/d), and relative protein, carbohydrate, and fat intake (g/kg/d) were predictors of siMS score and siMS risk score.

RESULTS

Twenty-five athletes (19.6 ± 1.3 years; 65.9 ± 7.0 kg; 23.5 ± 2.0 kg/m2; ABP 71.7 ± 28.2 g/d; PBP 30.0 ± 12.2 g/d) were included in the analyses. An inverse relationship was observed between PBP and the siMS score (F1, 22 = 5.498, p = 0.028) and siMS risk score (F1, 22 = 7.614, p = 0.011). The models explained 20% and 26% of the variance in siMS score and siMS risk score, respectively.

CONCLUSIONS

PBP was associated with lower MetS risk in Division III female athletes, while ABP, regardless of quality, was unrelated. These associations were independent of physical activity in this cohort of Division III female athletes.

Molecular Mechanisms of Healthy Aging: The Role of Caloric Restriction, Intermittent Fasting, Mediterranean Diet, and Ketogenic Diet-A Scoping Review

As the population ages, promoting healthy aging through targeted interventions becomes increasingly crucial. Growing evidence suggests that dietary interventions can significantly impact this process by modulating fundamental molecular pathways. This review focuses on the potential of targeted dietary strategies in promoting healthy aging and the mechanisms by which specific nutrients and dietary patterns influence key pathways involved in cellular repair, inflammation, and metabolic regulation. Caloric restriction, intermittent fasting, the Mediterranean diet, as well as the ketogenic diet showed promising effects on promoting healthy aging, possibly by modulating mTORC1 AMPK, an insulin signaling pathway. By understanding the intricate interplay between diet and molecular pathways, we can develop personalized dietary strategies that not only prevent age-related diseases, but also promote overall health and well-being throughout the aging process.

Therapeutic Potential of Various Intermittent Fasting Regimens in Alleviating Type 2 Diabetes Mellitus and Prediabetes: A Narrative Review

Intermittent fasting has drawn significant interest in the clinical research community due to its potential to address metabolic complications such as obesity and type 2 diabetes mellitus. Various intermittent fasting regimens include alternate-day fasting (24 h of fasting followed by 24 h of eating), time-restricted fasting (fasting for 14 h and eating within a 10 h window), and the 5:2 diet (fasting for two days and eating normally for the other five days). Intermittent fasting is associated with a reduced risk of type 2 diabetes mellitus-related complications and can slow their progression. The increasing global prevalence of type 2 diabetes mellitus highlights the importance of early management. Since prediabetes is a precursor to type 2 diabetes mellitus, understanding its progression is essential. However, the long-term effects of intermittent fasting on prediabetes are not yet well understood. Therefore, this review aims to comprehensively compile existing knowledge on the therapeutic effects of intermittent fasting in managing type 2 diabetes mellitus and prediabetes.

Time-restricted eating, the clock ticking behind the scenes

Introduction

Maintaining metabolic balance relies on accumulating nutrients during feeding periods and their subsequent release during fasting. In obesity and metabolic disorders, strategies aimed at reducing food intake while simulating fasting have garnered significant attention for weight loss. Caloric restriction (CR) diets and intermittent fasting (IF) interventions have emerged as effective approaches to improving cardiometabolic health. Although the comparative metabolic benefits of CR versus IF remain inconclusive, this review focuses on various forms of IF, particularly time-restricted eating (TRE).

Methods

This study employs a narrative review methodology, systematically collecting, synthesizing, and interpreting the existing literature on TRE and its metabolic effects. A comprehensive and unbiased search of relevant databases was conducted to identify pertinent studies, including pre-clinical animal studies and clinical trials in humans. Keywords such as "Obesity," "Intermittent Fasting," "Time-restricted eating," "Chronotype," and "Circadian rhythms" guided the search. The selected studies were critically appraised based on predefined inclusion and exclusion criteria, allowing for a thorough exploration and synthesis of current knowledge.

Results

This article synthesizes pre-clinical and clinical studies on TRE and its metabolic effects, providing a comprehensive overview of the current knowledge and identifying gaps for future research. It explores the metabolic outcomes of recent clinical trials employing different TRE protocols in individuals with overweight, obesity, or type II diabetes, emphasizing the significance of individual chronotype, which is often overlooked in practice. In contrast to human studies, animal models underscore the role of the circadian clock in mitigating metabolic disturbances induced by obesity through time-restricted feeding (TRF) interventions. Consequently, we examine pre-clinical evidence supporting the interplay between the circadian clock and TRF interventions. Additionally, we provide insights into the role of the microbiota, which TRE can modulate and its influence on circadian rhythms.

Gut microbiome remodeling and metabolomic profile improves in response to protein pacing with intermittent fasting versus continuous caloric restriction

The gut microbiome (GM) modulates body weight/composition and gastrointestinal functioning; therefore, approaches targeting resident gut microbes have attracted considerable interest. Intermittent fasting (IF) and protein pacing (P) regimens are effective in facilitating weight loss (WL) and enhancing body composition. However, the interrelationships between IF- and P-induced WL and the GM are unknown. The current randomized controlled study describes distinct fecal microbial and plasma metabolomic signatures between combined IF-P (n = 21) versus a heart-healthy, calorie-restricted (CR, n = 20) diet matched for overall energy intake in free-living human participants (women = 27; men = 14) with overweight/obesity for 8 weeks. Gut symptomatology improves and abundance of Christensenellaceae microbes and circulating cytokines and amino acid metabolites favoring fat oxidation increase with IF-P (p < 0.05), whereas metabolites associated with a longevity-related metabolic pathway increase with CR (p < 0.05). Differences indicate GM and metabolomic factors play a role in WL maintenance and body composition. This novel work provides insight into the GM and metabolomic profile of participants following an IF-P or CR diet and highlights important differences in microbial assembly associated with WL and body composition responsiveness. These data may inform future GM-focused precision nutrition recommendations using larger sample sizes of longer duration. Trial registration, March 6, 2020 (ClinicalTrials.gov as NCT04327141), based on a previous randomized intervention trial.

The pathophysiology of visceral adipose tissues in cardiometabolic diseases

Central pattern of fat distribution, especially fat accumulation within the intraabdominal cavity increases risks for cardiometabolic diseases. Portal hypothesis combined with a pathological remodeling in visceral fat is considered the major etiological factor explaining the independent contribution of visceral obesity to cardiometabolic diseases. Excessive remodeling in visceral fat during development of obesity leads to dysfunctions in the depot, characterized by hypertrophy and death of adipocytes, hypoxia, inflammation, and fibrosis. Dysfunctional visceral fat secretes elevated levels of fatty acids, glycerol, and proinflammatory and profibrotic cytokines into the portal vein directly impacting the liver, the central regulator of systemic metabolism. These metabolic and endocrine products induce ectopic fat accumulation, insulin resistance, inflammation, and fibrosis in the liver, which in turn causes or exacerbates systemic metabolic derangements. Elucidation of underlying mechanisms that lead to the pathological remodeling and higher degree of dysfunctions in visceral adipose tissue is therefore, critical for the development of therapeutics to prevent deleterious sequelae in obesity. We review depot differences in metabolic and endocrine properties and expendabilities as well as underlying mechanisms that contribute to the pathophysiological aspects of visceral adiposity in cardiometabolic diseases. We also discuss impacts of different weight loss interventions on visceral adiposity and cardiometabolic diseases.

Metabolic changes with intermittent fasting

BACKGROUND

The prevalence of obesity is rising globally and effective strategies to treat obesity are needed. Intermittent fasting, a dietary intervention for weight management, has received growing interest from the general public, as well as healthcare professionals, as a form of lifestyle intervention.

METHODS

We executed a rapid review using PUBMED database to identify systematic reviews that examined the impact of intermittent fasting on metabolic indices, published between 2011 and 2022.

RESULTS

Intermittent fasting leads to weight loss of a similar magnitude to continuous energy restriction. Most of the evidence shows that intermittent fasting leads to greater fat loss as measured by fat mass (kg) or body fat percentage compared to an ad libitum diet, but fat loss attained during intermittent fasting is not significantly different to continuous energy restriction, although recent evidence shows intermittent fasting to be superior. There is mixed evidence for the impact of intermittent fasting on insulin resistance, fasting glucose and lipid profile. Some studies focused on populations of Muslim people, which showed that Ramadan fasting may lead to weight loss and improvement of metabolic parameters during fasting, although the effects are reversed when fasting is finished.

CONCLUSIONS

Intermittent fasting is more effective than an ad libitum dietary intake, and equally or more effective as continuous energy restriction, for weight management. However, there is inconclusive evidence on whether intermittent fasting has a clinically beneficial effect on glucose and lipid metabolism.

Mammalian target of rapamycin inhibition impacts energy homeostasis and induces sex-specific body weight loss in humans

BACKGROUND

Previous data from a 2-year randomized controlled trial (CRAD001ADE12) indicated that mammalian target of rapamycin (mTOR) inhibition by everolimus slowed cyst growth in patients with autosomal-dominant polycystic kidney disease (ADPKD). During the trial, we noted body weight loss in some patients, particularly in women. We hypothesized that everolimus causes body weight reduction by reduced food intake and/or metabolic changes, which could lead to cachexia.

METHODS

Within a sub-analysis of the CRAD001ADE12 trial, body weight course was investigated regarding sex-specific differences in 433 adult ADPKD patients (everolimus, n = 215; placebo, n = 218). One hundred four out of 111 patients who participated in the clinical trial centre in Berlin were evaluated under everolimus/placebo therapy (on drug: everolimus, n = 48; placebo, n = 56) and after therapy (off drug: everolimus, n = 15; placebo, n = 18). Eating habits and nutrient/caloric intake were evaluated by validated questionnaires. Systemic and local metabolism was evaluated in four patients after an oral glucose load (OGL) by using calorimetry and adipose/muscle tissue microdialysis.

RESULTS

Within the 2-year CRAD001ADE12 trial, a significant body weight loss was observed in female patients on everolimus versus placebo (P = 0.0029). Data of the Berlin Cohort revealed that weight loss was greater in women on everolimus versus men (P < 0.01). After 9 months, women and men had lost 2.6 ± 3.8 and 0.8 ± 1.5 kg (P < 0.05) in body weight, respectively, and after 21 months, they had lost 4.1 ± 6.6 and 1.0 ± 3.3 kg (P < 0.05), respectively. On everolimus, caloric intake was significantly lower in women versus men (1510 ± 128 vs. 2264 ± 216 kcal/day, P < 0.05), caused mainly by a lower fat and protein intake in women versus men. Cognitive restraints, disinhibition and hunger remained unchanged. In a subgroup of patients resting metabolic rate was unchanged whereas OGL-induced thermogenesis was reduced (7 ± 2 vs. 11 ± 2 kcal, P < 0.05). Fasting and OGL-induced fat oxidation was increased (P < 0.05) on versus off everolimus. In adipose tissue, fasting lipolytic activity was increased, but lipolytic activity was inhibited similarly after the OGL on versus off everolimus, respectively. In skeletal muscle, postprandial glucose uptake and aerobic glycolysis was reduced in patients on everolimus.

CONCLUSIONS

mTOR inhibition by everolimus induces body weight reduction, specifically in female patients. This effect is possibly caused by a centrally mediated reduced food (fat and protein) intake and by centrally/peripherally mediated increased fat oxidation (systemic) and mobilization (adipose tissue). Glucose uptake and oxidation might be reduced in skeletal muscle. This could lead to cachexia and, possibly, muscle wasting. Therefore, our results have important implications for patients recieving immune-suppressive mTOR inhibition therapy.

Obesity and malnutrition in children and adults: A clinical review

Background

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

Methods

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

Discussion

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

Conclusion

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