International consensus on fasting terminology

Nutritional strategies in oncology: The role of dietary patterns in modulating tumor progression and treatment response

Dietary interventions can influence tumor growth by restricting tumor-specific nutritional requirements, altering the nutrient availability in the tumor microenvironment, or enhancing the cytotoxicity of anticancer drugs. Metabolic reprogramming of tumor cells, as a significant hallmark of tumor progression, has a profound impact on immune regulation, severely hindering tumor eradication. Dietary interventions can modify tumor metabolic processes to some extent, thereby further improving the efficacy of tumor treatment. In this review, we emphasize the impact of dietary patterns on tumor progression. By exploring the metabolic differences of nutrients in normal cells versus cancer cells, we further clarify how dietary patterns influence cancer treatment. We also discuss the effects of dietary patterns on traditional treatments such as immunotherapy, chemotherapy, radiotherapy, and the gut microbiome, thereby underscoring the importance of precision nutrition.

Cardiometabolic and obesity risk outcomes of dawn-to-dusk, dry intermittent fasting: Insights from an umbrella review

BACKGROUND & AIMS

This umbrella review comprehensively and systematically summarizes meta-analyses on the impact of dawn-to-dusk, dry intermittent fasting of Ramadan (RIF) on cardiometabolic and glucose homeostasis indicators.

METHODS

Twenty meta-analyses were examined on the effects of RIF on body fat percentage (BFP), fat mass, fat-free mass, body mass index (BMI), body weight (BW), waist circumference (WC), systolic and diastolic blood pressure (SBP, DBP), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglycerides (TG), and very low-density lipoprotein cholesterol (VLDL-C), fasting blood glucose (FBG), glycated hemoglobin (HbA1c), insulin resistance (HOMA-IR), serum insulin, leptin, and adiponectin. Results of continuous outcomes were pooled from included meta-analyses. We employed random-effects meta-analysis using the restricted maximum likelihood method to estimate heterogeneity. P-values were derived from standard meta-analytic tests, including Egger's test for small-study effects and the excess significance test for potential publication bias. Additionally, we applied criteria from Ioannidis' evidence classification to assess the credibility of the findings.

RESULTS

In healthy subjects, RIF was associated with significant reductions in BW (Hedges' G = -0.33; 95 % confidence interval (CI) = -0.37, -0.29; p-value = 2.63 × 10-52), WC (Hedges' G = -0.30; 95 % CI = -0.38, -0.23; p-value = 5.73 × 10-15), BFP (Hedges' G = -0.26; 95 % CI = -0.37, -0.14; p-value = 6.81 × 10-06), DBP (n = 3,456; Hedges' G = -0.26; 95 % CI = -0.38, -0.15; p-value = 9.18 × 10-06), TC (n = 9,314; Hedges' G = -0.16; 95 % CI = -0.25, -0.07; p-value = 6.27 × 10-04), and TG levels (n = 9,020; Hedges' G = -0.16; 95 % CI = -0.24, -0.08; p-value = 6.87 × 10-05). Moreover, in general population, TG (n = 16,688; Hedges' G = -0.15; 95 % CI = -0.22, -0.08; p-value <0.01) and FBG (n = 16,106; Hedges' G = -0.23; 95 % CI = -0.33, -0.13; p-value <0.01) were significantly reduced.

CONCLUSIONS

Dawn-to-dusk, dry RIF shows promise as a complementary therapy and preventive measure for reducing cardiometabolic and obesity-related risks. However, controlled studies are necessary to validate its effectiveness and fully understand its health implications.

Regulation of Metabolic Aging Through Adenosine Mono Phosphate-Activated Protein Kinase and Mammalian Target of Rapamycin: A Comparative Study of Intermittent Fasting Variations in Obese Young Women

Background/Objectives: Obesity accelerates metabolic aging through oxidative stress, inflammation, and mitochondrial dysfunction. AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) are nutrient-sensing pathways regulating metabolism. AMPK promotes energy metabolism and autophagy, while excessive mTOR activity contributes to aging. Intermittent fasting (IF), including time-restricted feeding (TRF)-limiting food intake to a 6 h window (18:6)-and alternate-day modified fasting (ADMF)-alternating 24 h fasting (≤25% daily caloric intake) with unrestricted feeding-may improve metabolic regulation. However, their effects on AMPK, mTOR, and metabolic age remain unclear. Methods: This quasi-experimental pre-test-post-test control group study compared the TRF and ADMF on metabolic age, AMPK, and mTOR in young obese women. Twenty-four participants (mean age: 21.29 ± 1.76 years; body fat: 36.92 ± 3.18%; BMI: 29.68 ± 3.70 kg/m2) were initially matched by BMI and assigned to Control, TRF, and ADMF groups. A total of 4 participants (1 Control, 3 ADMF) were excluded due to outlier values, yielding final group sizes: Control (n = 7), TRF (n = 8), and ADMF (n = 5). The intervention lasted 20 days. Results: A significant decrease in AMPK levels was observed in the ADMF group (p = 0.043), while changes in the TRF and Control groups were not significant. mTOR levels showed a decreasing trend but were not statistically significant. No significant changes were found in metabolic age. Conclusions: Twenty days of intermittent fasting intervention did not significantly affect AMPK, mTOR, or metabolic age in young obese women. TRF may more effectively enhance AMPK and reduce mTOR, while ADMF may better reduce metabolic age.

Predictors of Vitamin D Status in Religious and Intermittent Fasting: A Comparative Study in Orthodox Nuns and Women from the General Population

Background: Vitamin D plays a key role in bone metabolism and immune regulation. Populations with restricted sun exposure or limited dietary intake are particularly vulnerable to vitamin D deficiency. Orthodox Christian nuns represent a unique group in this regard, due to traditional clothing, limited outdoor activity, and prolonged religious fasting. However, few studies have compared them with lay individuals following similar dietary practices. Objective: This study aimed to investigate predictors of serum 25-hydroxyvitamin D [25(OH)D] concentrations in two female populations: Orthodox Christian nuns and women from the general population practicing intermittent (religious or non-religious) fasting. We also aimed to develop predictive models of vitamin D status for each group based on lifestyle and biochemical parameters. Methods: A total of 85 women (40 Orthodox nuns and 45 laywomen), aged 30-50 years, were enrolled. Serum 25(OH)D, parathyroid hormone (PTH), calcium levels, and anthropometric indices, including body mass index (BMI), total body fat, and visceral fat, were measured. Dietary calcium and vitamin D intake, as well as sun exposure, were assessed using validated questionnaires. Separate stepwise multiple regression models were constructed for each group to identify independent predictors of 25(OH)D concentrations. An additional combined model, including all participants, was also explored. Results: PTH was the most significant predictor, negatively correlating with 25(OH)D concentrations in both groups (p = 0.038), highlighting its regulatory role in vitamin D metabolism. When analyzed separately, the model for Orthodox nuns showed stronger explanatory power (adjusted R2 = 0.718; p = 0.013) compared with the control group (adjusted R2 = 0.362; p = 0.038), with PTH emerging as a key predictor in both. Conclusions: Distinct predictors of vitamin D status were identified in each group, reflecting the complex interplay between lifestyle and physiological factors. These findings suggest that targeted interventions, such as addressing PTH regulation in fasting populations or enhancing sun exposure in the general population, may be more effective in preventing vitamin D deficiency depending on the context.

Impact of Prolonged Fasting on the Oral Microbiome in Patients With Metabolic Syndrome: An Exploratory Secondary Analysis

AIM

To evaluate the effect of prolonged fasting on the oral microbiome in patients with metabolic syndrome (MetS).

MATERIALS AND METHODS

This follow-up study evaluated changes in the oral microbiome in a sub-cohort of 42 patients with MetS during prolonged fasting. Periodontal parameters such as bleeding on probing (BOP), plaque index (PI) and gingival crevicular fluid (GCF) measured in Periotron units (PU) as well as supra- and subgingival plaque samples were taken at baseline (T1), after 5-10 days of prolonged fasting (T2) and at 4-5-month follow-up (T3). Sequencing of the V4 hypervariable region of the 16S rRNA gene was performed to analyse the microbiome composition.

RESULTS

Significant reductions were observed in BOP: 36.4% ± 18.2% to 30.4% ± 15.6% (p = 0.01), PI: 66.9% ± 19.5% to 58.8% ± 23.4% (p < 0.01) and GCF: 83.6 ± 27.8 PU to 67.9 ± 30.3 PU (p < 0.01) post fasting. Microbiome α- and β-diversity did not change significantly. However, significant changes in specific bacterial genera were noted: Lachnospiraceae [G-3] increased only in subgingival samples; Eikenella and Peptostreptococcaceae [XI][G-7] increased; while Mitsuokella and Atopobium decreased in both sub- and supra-gingival samples.

CONCLUSION

Within the constraints of this analysis, prolonged fasting was found to be associated with reduced periodontal inflammation and selected shifts in the oral microbial composition. Larger controlled trials are needed to confirm these exploratory findings and determine their clinical relevance.

Exploring the Impact of Intermittent Fasting on Vascular Function and the Immune System: A Narrative Review and Novel Perspective

Vascular function is a critical determinant of cardiovascular health and all-cause mortality. Recent studies have suggested that intermittent fasting, a popular dietary strategy, elicits beneficial effects on vascular function. These studies also suggest that fasting-mediated improvements in vascular function coincide with reductions in systemic inflammation. However, the mechanisms that connect fasting, the immune system, and vascular function remain largely underexplored. The current review summarizes the effects of different intermittent fasting modalities on vascular health, focusing on endothelial dysfunction and arterial stiffness, 2 critical indices of vascular function. Improvements in vascular function are associated with reduced inflammation and are mechanistically linked to decreased circulating immune cells and their accumulation within the vascular wall and perivascular tissue. Recent data show that fasting redistributes circulating and tissue-resident immune cells to the bone marrow, affecting their inflammatory actions. However, there is no direct evidence relating immune cell redistribution to cardiovascular health. By relating fasting-induced immune cell redistribution to reduced inflammation and improved vascular function, we propose an exciting avenue of further exploration is determining whether fasting-induced immune cell redistribution impacts cardiovascular health.

Intermittent Fasting Regimes Reduce Gingival Inflammation: A Three-Arm Clinical Trial

AIM

To evaluate the effect of religious Bahá'í dry fasting (BF) or 16:8 time-restricted eating (TRE) compared with a regular diet (CG) on periodontal parameters during a modified experimentally induced gingivitis.

MATERIAL AND METHODS

All participants were asked to refrain from oral hygiene (3 sextant) for 9 days (T1-T2) and were followed for a total of 19 days (T3) while adhering to fasting or a regular diet and resuming oral hygiene. The primary outcome was bleeding on probing in the test sextant (BOP_s), Rustogi plaque index (RPI), gingival crevicular fluid (GCF), blood pressure (BP), body weight (BW), HbA1c and C-reactive protein (CRP) were measured (T1-T3) and ANCOVA and post hoc comparison were applied.

RESULTS

Sixty-six healthy participants were recruited. Forty-three were randomly assigned to TRE (n = 22) and CG (n = 21), while 23 followed BF, avoiding food and drinks during the day. At T2, BF demonstrated significantly less increase in BOP_s, and GCF increased in CG only. Analysis revealed significant differences in change for BOP_s between BF and CG (-9.48% [-17.18; -1.79]) and BF and TRE (-9.19% [-15.07; -3.32]) as well as for GCF between BF and CG (-0.06 μL [-7.22; -0.66]) and TRE and CG (-0.08 μL [-0.17; -0.00]).

CONCLUSION

This study indicates beneficial effects of different fasting protocols on oral experimental gingivitis and metabolic parameters, but results are limited by randomisation issues and potential bias in the BF group.

Targeting the Gut Microbiota's Role in Host Energy Absorption With Precision Nutrition Interventions for the Prevention and Treatment of Obesity

The field of precision nutrition aims to develop dietary approaches based on individual biological factors such as genomics or the gut microbiota. The gut microbiota, which is the highly individualized and complex community of microbes residing in the colon, is a key contributor to human physiology. Although gut microbes play multiple roles in the metabolism of nutrients, their role in modulating the absorption of dietary energy from foods that escape digestion in the small intestine has the potential to variably affect energy balance and, thus, body weight. The fate of this energy, and its subsequent impact on body weight, is well described in rodents and is emerging in humans. This narrative review is focused on recent clinical evidence of the role of the gut microbiota in human energy balance, specifically its impact on energy available to the human host. Despite recent progress, remaining gaps in knowledge present opportunities for developing and implementing strategies to understand causal microbial mechanisms related to energy balance. We propose that implementing rigorous microbiota-focused measurements in the context of innovative clinical trial designs will elucidate integrated diet-host-gut microbiota mechanisms. These mechanisms are primed to be targets for precision nutrition interventions to optimize energy balance to achieve desired weight outcomes. Given the magnitude and impact of the obesity epidemic, implementing these interventions within comprehensive weight management paradigms has the potential to be of public health significance.

Evaluation of therapeutic education on intermittent fasting in patients with secondary adrenal insufficiency: A clinical trial

OBJECTIVES

Intermittent fasting was associated with complications in patients with adrenal insufficiency (AI). The study aimed to evaluate the impact of therapeutic education and drug adjustment on Ramadan fasting outcomes in patients with secondary AI (SAI).

METHODS

A case-control prospective interventional study including patients with SAI willing to fast Ramadan 2023, and age-, gender-, and body mass index-matched healthy fasting controls. Before Ramadan, clinical examination, education for lifestyle measures, and hydrocortisone intake adjustment were performed. The occurrence of complications and the number of fasted days during Ramadan 2023 were reported and compared with those of Ramadan 2022 in patients and controls.

RESULTS

A total of 50 patients; 33 women, median age: 43 years (34-55), median duration of SAI: 7.5 years (4-12.5), and 100 controls were enrolled, and fasted in 2023. Thirty-four patients and 100 controls fasted in 2022, corresponding to a 32% increase in fasting patients. Compared to 2022, there was a significant decrease in the frequency of complications in 2023 in patients compared to controls. The number of fasted days did not change. No severe event happened during the 2023 fasting. In patients, apart from the age that was higher in former fasters compared to new fasters, age, gender, body mass index, blood pressure levels, renal clearance, disease duration, and daily hydrocortisone dose were not associated with new versus former fasters, high versus low-risk patients, or incomplete versus complete month fasters.

CONCLUSIONS

Therapeutic education enabled more patients with SAI to fast and reduced the frequency of complications during fasting. Registered on "clinical trials.gov," April 12, 2023, under the identifier ID: NCT05827965.

Interrelations of Leptin and Interleukin-6 in Vitamin D Deficient and Overweight Orthodox Nuns from Northern Greece: A Pilot Study

Background/Objectives: Athonian fasting, a rigorous form of intermittent fasting practiced by Christian Orthodox nuns and a subset of the Mediterranean diet, has known health benefits, but its impact on the interplay of adipokines, inflammatory cytokines, and vitamin D status remains under-investigated. This study aimed to elucidate these relationships within this controlled dietary context. Methods: This cross-sectional study examined the interplay of leptin, interleukin-6 (IL-6), and vitamin D in 41 overweight, vitamin D-sufficient Christian Orthodox nuns practicing Athonian fasting. Anthropometric, biochemical, and inflammatory markers were assessed in the nuns (mean age 53.4 ± 17.1 years, median monastery stay 17 years, median BMI 26.8 kg/m2). Results: Analysis revealed significant positive correlations between age and monastery stay (r = 0.615, p < 0.001), age and visceral fat (ρ = 0.791, p < 0.001), age and IL-6 (ρ = 0.647, p < 0.001), and BMI and IL-6 (ρ = 0.622, p < 0.001). Strong associations existed between adiposity (BMI, body fat, visceral fat), leptin, and IL-6. Specifically, body fat showed substantial positive correlations with visceral fat (ρ = 0.858, p < 0.001), leptin (ρ = 0.538, p < 0.001), and IL-6 (ρ = 0.675, p < 0.001). Visceral fat demonstrated strong positive correlations with leptin (ρ = 0.613, p < 0.001) and IL-6 (ρ = 0.741, p < 0.001). A significant positive correlation was also observed between leptin and IL-6 (ρ = 0.507, p = 0.003). Conversely, a significant negative correlation was found between 25(OH)D and PTH (ρ = -0.380, p = 0.016). Multivariate regression analysis did not reveal independent effects of leptin or IL-6 after adjusting for other factors. Conclusions: This study reveals a complex interplay of adiposity, inflammation, and vitamin D status in this unique population of Orthodox monastery fasters. The strong correlations suggest potential targets for interventions aimed at improving metabolic health. Future research should investigate the effects of vitamin D within the context of Athonian fasting.

Body Composition and Its Outcomes and Management in Multiple Sclerosis: Narrative Review

Background: There is emerging interest in obesity and its prevalence, outcomes, and management in people with multiple sclerosis (MS). Body mass index (BMI) is the traditional marker of obesity in MS, whereas body composition, inclusive of specific body tissue compartments (e.g., fat, bone, and muscle), is often overlooked despite its relevance. Objective: This narrative review (a) underscored the use and utility of dual-energy X-ray absorptiometry (DEXA) as an accurate and reliable measure of body composition; (b) thematically analyzed and synthesized the current evidence regarding body composition (using DEXA); and (c) determined gaps to be addressed in future research. Methods: The structure and reporting of this narrative review followed the guiding criteria outlined in the Scale for the Assessment of Narrative Review Articles (SANRA). The relevant literature for this narrative review was identified via a PubMed search utilizing combined search terms such as 'body composition' and 'multiple sclerosis'. The identified research was then organized by the authors into major themes and sub-themes. The articles described within the narrative review were based on saturation of the identified themes and sub-themes. Results: Three major themes were identified, namely (1) comparison of body composition between people with MS and non-MS controls (2 meta-analyses); (2) examination of the relationships between body composition and a range of outcomes (14 cross-sectional studies); and (3) interventions that report and/or target body composition in MS (11 clinical trials). Conclusions: This narrative review mapped the existing evidence regarding body composition in MS, and posits body composition as a novel, informative, and targeted concept for this population. The narrative review underscores the importance of randomized controlled trials that focus on body composition as a significant and modifiable outcome. Such research could improve the understanding of obesity and poor body composition in MS and identify useful clinical recommendations for diagnosis and management.

Early downmodulation of tumor glycolysis predicts response to fasting-mimicking diet in triple-negative breast cancer patients

In preclinical experiments, cyclic fasting-mimicking diets (FMDs) showed broad anticancer effects in combination with chemotherapy. Among different tumor types, triple-negative breast cancer (TNBC) is exquisitely sensitive to FMD. However, the antitumor activity and efficacy of cyclic FMD in TNBC patients remain unclear. Here, we show that a severely calorie-restricted, triweekly, 5-day FMD regimen results in excellent pathologic complete response (pCR) rates (primary endpoint) and long-term clinical outcomes (secondary endpoints) when combined with preoperative chemotherapy in 30 patients with early-stage TNBC enrolled in the phase 2 trial BREAKFAST. Bulk and single-cell RNA sequencing analysis revealed that highly glycolytic cancer cells, myeloid cells, and pericytes from tumors achieving pCR undergo a significant, early downmodulation of pathways related to glycolysis and pyruvate metabolism. Our findings pave the wave for conducting larger clinical trials to investigate the efficacy of cyclic FMD in early-stage TNBC patients and to validate early changes of intratumor glycolysis as a predictor of clinical benefit from nutrient restriction. This study was registered at Clinicaltrials.gov (NCT04248998).

Harnessing tumor metabolism during cancer treatment: A narrative review of emerging dietary approaches

Cancer is currently one of the biggest public health challenges worldwide, ranking as the second leading cause of death globally. To date, strong epidemiological associations have been demonstrated between unhealthy lifestyles and eating habits, i.e. obesity, and an increased risk of developing cancer. However, there is limited evidence regarding the impact of specific dietary regimes on cancer outcomes during conventional cancer treatments. This paper systematically reviews and evaluates preclinical and clinical evidence regarding the effects of fasting, fast-mimicking diet, ketogenic diet, vegan diet, alkaline diet, paleolithic diet, the Gerson regimen, and macrobiotic diet in the context of cancer treatments. Clinical trials on dietary regimes as complementary cancer therapy are limited by significant differences in trial design, patient characteristics, and cancer type, making it difficult to draw conclusions. In the future, more uniformly controlled clinical trials should help to better define the role of diets in cancer management.

Dietary Restrictions and Cancer Prevention: State of the Art

Worldwide, almost 10 million cancer deaths occurred in 2022, a number that is expected to rise to 16.3 million by 2040. Primary prevention has long been acknowledged as a crucial approach to reducing cancer incidence. In fact, between 30 and 50 percent of all tumors are known to be preventable by eating a healthy diet, staying active, avoiding alcohol, smoking, and being overweight. Accordingly, many international organizations have created tumor prevention guidelines, which underlie the importance of following a diet that emphasizes eating plant-based foods while minimizing the consumption of red/processed meat, sugars, processed foods, and alcohol. However, further research is needed to define the relationship between the effect of specific diets or nutritional components on cancer prevention. Interestingly, reductions in food intake and dietetic restrictions can extend the lifespan of yeast, nematodes, flies, and rodents. Despite controversial results in humans, those approaches have the potential to ameliorate health via direct and indirect effects on specific signaling pathways involved in cancer onset. Here, we describe the latest knowledge on the cancer-preventive potential of dietary restrictions and the biochemical processes involved. Molecular, preclinical, and clinical studies evaluating the effects of different fasting strategies will also be reviewed.

Current Evidence on the Impact of Diet, Food, and Supplement Intake on Breast Cancer Health Outcomes in Patients Undergoing Endocrine Therapy

BACKGROUND/OBJECTIVES

The most common type of breast cancer (BRC) in women is estrogen/progesterone receptor positive. First-line treatment includes endocrine therapy, either with aromatase inhibitors or tamoxifen to reduce estrogen levels. Among the side effects produced by this treatment, aromatase inhibitor-induced arthralgia is the most common, affecting the patients' overall health and quality of life (QoL). The objectives here were to evaluate interventions examining the impact of modified diets, supplements, and/or some food components on health outcomes in BRC patients undergoing endocrine therapy.

METHODS

The literature search was performed in PubMed, Scopus, and Web of Science from June 2024, as well as manually, through the end of November 2024. The search was limited to studies of women diagnosed with estrogen/progesterone-receptor-positive BRC with selected articles reporting interventions with diet, food, or supplement intake and examining the relevant health outcomes. Studies not focusing on BRC patients undergoing endocrine therapy or not including specific health outcomes were excluded.

RESULTS

The search uncovered 1028 studies; after the removal of duplicates, abstracts, and irrelevant studies, 53 were closely examined, with 26 evaluated and presented here. The outcomes were changes in bone and body composition, cardiovascular disease risks, inflammation, and QoL.

CONCLUSIONS

The examined evidence suggests that adherence to dietary patterns such as the Mediterranean or a low-fat diet, and a higher intake of fruits and vegetables were beneficial for various outcomes. Additionally, supplementation with some foods/components (dried plum, red clover) contributed to improving/maintaining bone and body composition, especially in overweight/obese patients. Supplementation with vitamin D or omega-3 improved lipid and angiogenic parameters and QoL. Although these results are promising, the effects of each supplement/food cannot be summarized due to the diverse nature of study designs, patients, and supplement dosages. Further studies are needed to explore the effects of specific nutritional interventions (including the newest, like fasting-mimicking diets and whole-grain cereal diets) on various health outcomes in BRC survivors during endocrine therapy, and to derive universal recommendations.

The catabolic - anabolic cycling hormesis model of health and resilience

A major goal of aging research is to identify ways of extending productive and disease-free lifespans. Here we present the catabolic - anabolic cycling hormesis (CACH) model for optimizing health. The CACH model is based on the concept that cells and organ systems respond to catabolic challenges in ways that bolster their resilience and that an anabolic recovery period is required to effectuate the benefits of the catabolic challenge. As two prominent real-world examples we highlight the literature on the molecular and cellular mechanisms by which physical exercise and intermittent fasting bolster cellular and organismal performance and resilience, and suppress disease processes. Over periods of weeks and months the CACH of exercise and fasting promote optimal health. The hormesis concept is integral to the CACH model and predicts an upper limit to the beneficial effects of catabolic - anabolic cycling that reflects a limit of biological plasticity. This paper extends the hormesis model of health by proposing that 1) it is comprised of two complementary phases: catabolic (adaptive stress responses and conservation of resources) and anabolic (growth and plasticity) and, 2) that CACH is metabolically integrated, quantitatively flexible and dynamically regulated. This model has important implications for future basic and translational research in the fields of aging and related disease processes.

Lipoprotein(a) and the atherosclerotic burden - Should we wait for clinical trial evidence before taking action?

The fact that lipoprotein(a) levels should be regarded as a causal residual risk factor in the atherosclerotic cardiovascular diseases (ASCVD) is now a no-brainer. This review article aims to summarize the latest evidence supporting the causal role of lipoprotein(a) in ASCVD and the potential strategies to reduce the lipoprotein(a) burden until clinical trial results are available. Epidemiological and genetic data demonstrate the causal link between lipoprotein(a) and increased ASCVD risk. That being said, a specific question comes to mind: "must we wait for outcome trials in order to take action?". Given that lipoprotein(a) levels predict incident ASCVD in both primary and secondary prevention contexts, with a linear risk gradient across its distribution, measuring lipoprotein(a) can unequivocally help identify patients who may later benefit from specific lipoprotein(a)-lowering therapies. This understanding has led various National Societies to recommend dosing lipoprotein(a) in high-risk individuals and to support the recommendation of measuring lipoprotein(a) levels at least once in every adult for risk stratification.

Impact of daily fasting duration on body composition and cardiometabolic risk factors during a time-restricted eating protocol: a randomized controlled trial

BACKGROUND

Time-restricted eating (TRE) is a dietary regimen that limits food intake for at least 12 h daily. Unlike other fasting protocols, TRE does not dictate what or how much to eat but rather focuses on the timing of meals. This approach has been previously demonstrated to improve body composition in individuals with obesity or metabolic impairments. However, its impact on body composition and cardiometabolic factors in healthy individuals remains unclear. Furthermore, the optimal fasting duration is still debated. Thus, we aimed to compare the effects of 8 weeks of different fasting durations on body composition and biochemical parameters in metabolically healthy, non-trained individuals using a parallel randomized controlled trial.

METHODS

Forty-one volunteers were randomly assigned to one of the four experimental groups: TRE 16:8 (16 h of fasting,8 h of eating), TRE 14:10 (14 h of fasting,10 h of eating), TRE 12:12 (12 h of fasting,12 h of eating) or a normal diet group (ND; no dietary restriction). Participants underwent body composition measurements and blood tests for lipid profiles (i.e., total cholesterol, LDL, HDL, and triglycerides), fasting glucose, leptin, and anabolic hormones (i.e., insulin and testosterone) levels. Data were analyzed using both intention-to-treat (ITT) and per-protocol (PP) analysis to account for compliance. A two-way ANOVA for repeated measures was employed to assess interactions between time and group.

RESULTS

In the ITT analysis, TRE 16:8 reduced body mass (-2.46%, p = 0.003) and absolute fat mass (-8.65%, p = 0.001) with no changes in lean soft tissue and in calorie intake. These results were consistent with the PP analysis which included 8 participants in TRE 16:8, 5 in TRE 14:10, 9 in TRE 12:12, and the entire ND group. Participants in the TRE 16:8 group spontaneously reduced their total caloric intake, although this reduction was not statistically significant. None of the other measurements significantly changed after 8 weeks.

CONCLUSIONS

Our results suggest that a 16-hour fasting window, even without caloric restriction, may be a viable strategy for improving body composition in healthy and non-trained individuals, whereas a shorter fasting period may be insufficient to produce significant changes in a healthy population.

TRIAL REGISTRATION

NCT, NCT04503005. Registered 4 August 2020, https://clinicaltrials.gov/study/NCT04503005 .

Lipid sensing by PPARα: Role in controlling hepatocyte gene regulatory networks and the metabolic response to fasting

Peroxisome proliferator-activated receptors (PPARs) constitute a small family of three nuclear receptors that act as lipid sensors, and thereby regulate the transcription of genes having key roles in hepatic and whole-body energy homeostasis, and in other processes (e.g., inflammation), which have far-reaching health consequences. Peroxisome proliferator-activated receptor isotype α (PPARα) is expressed in oxidative tissues, particularly in the liver, carrying out critical functions during the adaptive fasting response. Advanced omics technologies have provided insight into the vast complexity of the regulation of PPAR expression and activity, as well as their downstream effects on the physiology of the liver and its associated metabolic organs. Here, we provide an overview of the gene regulatory networks controlled by PPARα in the liver in response to fasting. We discuss impacts on liver metabolism, the systemic repercussions and benefits of PPARα-regulated ketogenesis and production of fibroblast growth factor 21 (FGF21), a fasting- and stress-inducible metabolic hormone. We also highlight current challenges in using novel methods to further improve our knowledge of PPARα in health and disease.

Effects of Religious Fasting on Markers of Oxidative Status in Vitamin D-Deficient and Overweight Orthodox Nuns versus Implementation of Time-Restricted Eating in Lay Women from Central and Northern Greece

Background/Objectives: The Mediterranean diet has been widely suggested to exert significant beneficial effects on endothelial oxidative status and cardiometabolic health. Greek Orthodox monasteries, due to their specific nutritional and sartorial habits, comprise a population thatstrictly adheres to nutritional patterns with restricted eating and a plant-based subset of the Mediterranean diet, often accompanied by profound hypovitaminosis D. Time-restricted eating (TRE) is also adopted bya large part of the general lay Greek population for health-promoting reasons, without restrictions on animal product consumption, as imposed by Orthodox religious fasting. However, the comparative effects of these nutritional patterns on oxidative stress markers remain scarce. Methods: The present study attempted to evaluate the effects of Christian Orthodox fasting (COF) in a group of vitamin D-deficient and overweight Orthodox nuns from Central and Northern Greece compared to the implementation of TRE, a 16:8 dietary regimen (16 h of food abstinence and 8 h of feeding) in a cohort of adult women from the general population from the same region with regard to markers of endothelial oxidative status. A group of 50 women from two Orthodox monasteries in Northern Greece and one group of 50 healthy lay women were included. During the enrollment, a detailed recording of their dietary habits was performed, along with a scientific registry of their demographic and anthropometric characteristics (via bioimpedance). The Orthodox nuns followed a typical Orthodox fasting regimen [daily feeding window (8 a.m.-4 p.m.)], whereas the lay women followed a TRE 16:8 regimen with the same feeding time-window with a recommendation to follow a low-fat diet, without characteristics of the Mediterranean diet. We included a complete biochemical analysis, as well as calciotropic profiles [calcium-Ca, albumin, parathyroid hormone-PTH, and 25-hydroxyvitamin D-25(OH)D] and markers of TAC (total antioxidant capacity), GSH (glutathione),and thiobarbituric acid reactive substances (TBARSs) concentrations as markers of oxidative status. Results: All the groups were compared at the baseline regarding their calcium, PTH, and 25(OH)D concentrations, with no statistically significant differences between the groups apart from higher PTH levels in the nuns due to lower 25(OH)D levels. The Orthodox nuns manifested a lower median GSH compared to the controls (6.0 vs. 7.2, p 0.04) and a higher median TAC (0.92 vs. 0.77, p < 0.001). The TBARS comparisons showed no significant difference between the two groups. No significant associations of oxidative status with 25(OH)D, PTH, and the markers of glucose homeostasis were evident. Conclusions: The results of this small pilot study indicate that both dietary regimens have advantages over the oxidative markers compared to each other, with increased TAC in the group of Orthodox nuns after a 16-week period of COF compared to a 16:8 TRE and increased GSH concentrations in the lay women group. Future randomized trials are required to investigate the superiority or non-inferiority between these dietary patterns in the daily clinical setting.

Comparing caloric restriction regimens for effective weight management in adults: a systematic review and network meta-analysis

BACKGROUND

Randomized controlled trials have confirmed the effectiveness of four prevalent caloric restriction regimens in reducing obesity-related health risks. However, there is no consensus on the optimal regimen for weight management in adults.

METHODS

We systematically searched PubMed, Embase, Web of Science, and Cochrane CENTRAL up to January 15, 2024, for randomized controlled trials (RCT) involving adults, evaluating the weight-loss effects of alternate day fasting (ADF), short-term fasting (STF), time-restricted eating (TRE), and continuous energy restriction (CER). The primary outcome was body weight, with secondary outcomes including BMI, fat mass, lean mass, waist circumference, fasting glucose, HOMA-IR, and adverse events. Bayesian network meta-analysis was conducted, ranking regimens using the surface under the cumulative ranking curve and the probability of being the best. Study quality was assessed using the Confidence in Network Meta-Analysis tool.

RESULTS

Data from 47 RCTs (representing 3363 participants) were included. ADF showed the most significant body weight loss (Mean difference (MD): -3.42; 95% Confidence interval (CI): -4.28 to -2.55), followed by TRE (MD: -2.25; 95% CI: -2.92 to -1.59). STF (MD: -1.87; 95% CI: -3.32 to -0.56) and CER (MD: -1.59; 95% CI: -2.42 to -0.79) rank third and fourth, respectively. STF lead to decline in lean mass (MD: -1.26; 95% CI: -2.16, -0.47). TRE showed benefits on fasting glucose (MD: -2.98; 95% CI: -4.7, -1.26). Subgroup analysis revealed all four caloric restriction regimens likely lead to modest weight loss after 1-3 months, with ADF ranked highest, but by 4-6 months, varying degrees of weight regain occur, particularly with CER, while interventions lasting 7-12 months may result in effective weight loss, with TRE potentially ranking first during both the 4-6 months and 7-12 months periods. ADF showing fewer and shorter-lasting physical symptoms.

CONCLUSION

All four included regiments were effective in reducing body weight, with ADF likely having the most significant impact. Each regimen likely leads to modest weight loss after 1-3 months, followed by weight regain by 4-6 months. However, interventions lasting 7-12 months achieve greater weight loss overall.

TRIAL REGISTRATION

PROSPERO: CRD42022382478.