BACKGROUND: Obesity and metabolic syndrome (MetS) have become urgent worldwide health problems, predisposing patients to unfavorable myocardial status and thyroid dysfunction. Low-carbohydrate diet (LCD) and time-restricted eating (TRE) have been confirmed to be effective methods for weight management and improving MetS, but their effects on the myocardium and thyroid are unclear.
METHODS: We conducted a secondary analysis in a randomized clinical diet-induced weight-loss trial. Participants (N = 169) diagnosed with MetS were randomized to the LCD group, the 8 h TRE group, or the combination of the LCD and TRE group for 3 months. Myocardial enzymes and thyroid function were tested before and after the intervention. Pearson\'s or Spearman\'s correlation was assessed between functions of the myocardium and thyroid and cardiometabolic parameters at baseline.
RESULTS: A total of 162 participants who began the trial were included in the intention-to-treat (ITT) analysis, and 57 participants who adhered to their assigned protocol were involved in the per-protocol (PP) analysis. Relative to baseline, lactate dehydrogenase, creatine kinase MB, hydroxybutyrate dehydrogenase, and free triiodothyronine (FT3) declined, and free thyroxine (FT4) increased after all 3 interventions (both analyses). Creatine kinase (CK) decreased only in the TRE (- 18 [44] U/L, P < 0.001) and combination (- 22 [64] U/L, P = 0.003) groups (PP analysis). Thyrotropin (- 0.24 [0.83] μIU/mL, P = 0.011) and T3 (- 0.10 ± 0.04 ng/mL, P = 0.011) decreased in the combination group (ITT analysis). T4 (0.82 ± 0.39 μg/dL, P = 0.046), thyroglobulin antibodies (TgAb, 2 [1] %, P = 0.021), and thyroid microsomal antibodies (TMAb, 2 [2] %, P < 0.001) increased, while the T3/T4 ratio (- 0.01 ± 0.01, P = 0.020) decreased only in the TRE group (PP analysis). However, no significant difference between groups was observed in either analysis. At baseline, CK was positively correlated with the visceral fat area. FT3 was positively associated with triglycerides and total cholesterol. FT4 was negatively related to insulin and C-peptide levels. TgAb and TMAb were negatively correlated with the waist-to-hip ratio.
CONCLUSIONS: TRE with or without LCD confers remarkable metabolic benefits on myocardial status and thyroid function in subjects with MetS.
BACKGROUND: ClinicalTrials.gov, NCT04475822.

OBJECTIVE: Time-restricted eating (TRE) and low-carbohydrate diet (LCD) can improve multiple cardiometabolic parameters in patients with metabolic syndrome (MetS), but their effects on psychosocial health and satiety are unclear. In this study, we aimed to evaluate the effects of TRE, LCD, and their combination (TRE + LCD) on quality of life (QoL), sleep, mood, appetite, and metabolic hormones in patients with MetS.
METHODS: This is a secondary analysis of a single-center, 3-month, open-label, randomized clinical trial investigating the effects of TRE, LCD, and TRE + LCD on weight and cardiometabolic parameters in individuals with MetS. This secondary analysis examined QoL, sleep, mood, and appetite using the Rand 36-Item Short Form (SF-36); Pittsburgh Sleep Quality Index (PSQI); Depression, Anxiety, and Stress Scale; and Eating Behavior Rating Scale, respectively, as well as measured levels of metabolic hormones including leptin, amylin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1 (GLP-1), pancreatic polypeptide (PP), and peptide YY. Between-group comparisons were conducted via one-way ANOVAs and post hoc LSD tests for normally distributed variables or Kruskal‒Wallis H tests and the Nemenyi test for abnormally distributed variables. P < 0.017 was considered significant in multiple comparisons following Bonferroni adjustment.
RESULTS: A total of 162 participants (mean [SD] age, 41.2 [9.9] years; mean [SD] body mass index, 29.3 [3.4] kg/m2; 102 [63%] men) who started the intervention were analyzed. After 3 months, only the TRE group decreased GLP-1 levels (-0.9 [IQR, -1.9 to -0.3] pg/mL; P = 0.002), increased PP levels (8.9 [IQR, -7.6 to 71.8] pg/mL; P = 0.011), physical functioning in the SF-36 (5.2 [95% CI, 1.9 to 8.5]; P = 0.001), social functioning in the SF-36 (9.1 [95% CI, 2.5 to 15.6]; P = 0.005), role-physical in the SF-36 (24.1 [95% CI, 11.8 to 36.4]; P < 0.001), role-emotional in the SF-36 (22.4 [95% CI, 12.6 to 32.2]; P < 0.001), and sleep efficiency in the PSQI (0.29 [95% CI, 0.03 to 0.55]; P = 0.021). Compared with changes in LCD, TRE further increased general health in the SF-36 (9.7 [95% CI, 3.3 to 16.0]; P = 0.006). Relative to the changes of TRE + LCD, TRE significantly increased role-emotional in the SF-36 (19.9 [95% CI 4.9 to 34.8]; P = 0.006). Changes in sleep quality, mood status, appetite, and metabolic hormones did not differ among three groups. Greater weight loss was associated with decreased leptin levels (r = 0.538), decreased amylin levels (r = 0.294), reduced total appetite scores (r = 0.220), and improved general health (r = -0.253) (all P ≤ 0.01).
CONCLUSIONS: TRE, LCD, and TRE + LCD all could improve psychosocial health and reduce appetite. Notably, TRE yielded greater benefits in QoL compared with LCD or TRE + LCD in individuals with MetS.
BACKGROUND: ClinicalTrials.gov Identifier: NCT04475822.

BACKGROUND: In the face of the growing global burden of cancer, there is increasing interest in dietary interventions to mitigate its impacts. Pre-clinical evidence suggests that time-restricted eating (TRE), a type of intermittent fasting, induces metabolic effects and alterations in the gut microbiome that may impede carcinogenesis. Research on TRE in cancer has progressed to human studies, but the evidence has yet to be synthesized.
OBJECTIVE: The objective of this study was to systematically evaluate the clinical and/or metabolomic effects of TRE compared with ad libitum eating or alternative diets in people with cancer.
METHODS: Ovid MEDLINE, Ovid Embase, CINAHL, Ovid Cochrane Central Register of Control Trials (CENTRAL), Web of Science Core Collection (ESCI, CPCI-SSH, CPCI-S), and SCOPUS were searched up to January 4, 2023, using the core concepts of \"intermittent fasting\" and \"cancer.\" Original study designs, protocols, and clinical trial registries were included.
METHODS: After evaluating 13 900 results, 24 entries were included, consisting of 8 full articles, 2 abstracts, 1 published protocol and 13 trial registries. All data were extracted, compared, and critically analyzed.
METHODS: There was heterogeneity in the patient population (eg, in tumor sites), TRE regimens (eg, degree of restriction, duration), and clinical end points. A high rate (67-98%) of TRE adherence was observed, alongside improvements in quality of life. Four articles assessed cancer markers and found a reduction in tumor marker carcinoembryonic antigen, reduced rates of recurrence, and a sustained major molecular response, following TRE. Five articles demonstrated modified cancer risk factors, including beneficial effects on body mass index, adiposity, glucoregulation, and inflammation in as short a period as 8 weeks. None of the completed studies assessed the effect of TRE on the microbiome, but analysis of the microbiome is a planned outcome in 2 clinical trials.
CONCLUSIONS: Preliminary findings suggest that TRE is feasible and acceptable by people with cancer, may have oncological benefits, and improves quality of life.
BACKGROUND: PROSPERO registration No. CRD42023386885.

Intermittent religious fasting increases the risk of hypo- and hyperglycemia in individuals with diabetes, but its impact on those without diabetes has been poorly investigated. The aim of this preliminary study was to examine the effects of religious Bahá\'í fasting (BF) on glycemic control and variability and compare these effects with time-restricted eating (TRE). In a three-arm randomized controlled trial, 16 subjects without diabetes were assigned to a BF, TRE, or control group. Continuous glucose monitoring and food intake documentation were conducted before and during the 19 days of the intervention, and the 24 h mean glucose and glycemic variability indices were assessed. The BF and TRE groups, but not the control group, markedly reduced the daily eating window while maintaining macronutrient composition. Only the BF group decreased caloric intake (-677.8 ± 357.6 kcal, p = 0.013), body weight (-1.92 ± 0.95 kg, p = 0.011), and BMI (-0.65 ± 0.28 kg, p = 0.006). Higher maximum glucose values were observed during BF in the within-group (+1.41 ± 1.04, p = 0.039) and between-group comparisons (BF vs. control: p = 0.010; TRE vs. BF: p = 0.022). However, there were no alterations of the 24 h mean glucose, intra- and inter-day glycemic variability indices in any group. The proportions of time above and below the range (70-180 mg/dL) remained unchanged. BF and TRE do not exhibit negative effects on glycemic control and variability in subjects without diabetes.

OBJECTIVE: Time-restricted eating (TRE) which consists of restricting the eating window to typically 4-8h (while fasting for the remaining hours of the day) has been proposed as a non-pharmacological strategy with cardio-metabolic benefits but little is known about its metabolic impact in type 2 diabetes (T2DM). We evaluated whether TRE can improve pancreatic beta-cell function and metabolic status in overweight individuals with early T2DM.
METHODS: In a randomized cross-over trial, 39 participants [mean 2.9 years of diabetes duration, baseline glycated hemoglobin (HbA1c) 6.6% ± 0.7% and body mass index (BMI) 32.4 ± 5.7 kg/m2] were randomized to either an initial intervention consisting of 6-weeks of TRE (20h-fasting/4h-eating) or standard lifestyle. The primary outcome of beta-cell function was assessed by Insulin Secretion-Sensitivity Index-2 (ISSI-2) derived from an oral glucose tolerance test. Trial registration: clinicaltrials.gov NCT05717127.
RESULTS: As compared to standard lifestyle, TRE induced a 14% increase in ISSI-2 (+14.0 ± 39.2%, p = 0.03) accompanied by 14% reduction of hepatic insulin resistance as evaluated by HOMA-IR [-11.6% (-49.3-21.9), p = 0.03]. Fasting glucose did not differ between interventions, but TRE yielded a significant reduction in HbA1c (-0.32 ± 0.48%, p <0.001). These metabolic improvements were coupled by a reduction of body weight of 3.86% (-3.86 ± 3.1%, p <0.001) and waist circumference of 3.8 cm (-3.8 ± 7.5 cm, p = 0.003).
CONCLUSIONS: TRE improved beta-cell function and insulin resistance in overweight patients with early diabetes, accompanied by beneficial effects on adiposity.

UNASSIGNED: 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).
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: Time-restricted eating (TRE), a dietary pattern reducing the duration of daily food consumption, has recently gained popularity. Existing studies show the potential benefits of TRE for cardiometabolic health. Uncertainty remains about whether these benefits are solely from altered meal timing or influences on other health behaviors, including sleep. Despite growing scientific interest in the effects of TRE on sleep parameters, the topic has not been systematically explored.
UNASSIGNED: This review examined the effects of TRE interventions (daily fasting duration ≥14 h) lasting at least 8 weeks on objective and subjective sleep parameters. Six randomized control trials were identified through Pubmed, Embase, Google Scholar, and Scopus through September 2023.
UNASSIGNED: Of the included studies, three employed objective sleep measures using wearables and five studies assessed sleep subjectively through self-report questionnaires. Only one study reported significant improvements in subjective sleep quality following a TRE intervention. Additionally, one study found significant decreases in sleep duration, two studies found significant decreases in sleep efficiency, and one found significant increases in sleep onset latency.
UNASSIGNED: Current evidence indicates that short to mid-term TRE does not typically worsen sleep parameters. However, some populations may experience reduced sleep disturbances, while others may experience reductions in sleep efficiency. Longer duration studies with objective sleep assessments are needed to better understand the effects of TRE on sleep parameters.

Time-restricted eating (TRE) effectively improves healthspan, including controlling obesity and improving metabolic health. To date, few meta-analyses have been conducted to explore the effects of various protocols of TRE in participants with overweight/obesity. PubMed, Embase and the Cochrane Central Register of Controlled Trials were searched up until October 15, 2022. Randomized and non-randomized clinical trials that investigated the effect of TRE on body weight, body composition and cardiometabolic parameters in participants with overweight/obesity were included. Mean differences of changes from the baseline were used for all analyses between the two groups. Prespecified subgroup analyses based on different protocols of TRE were performed. Twenty-three studies were included in the meta-analysis with 1867 participants. TRE interventions led to significant changes in body weight. When energy restriction strategies were conducted in both the TRE and control groups, the weight-loss effect of TRE remained significant. TRE with 4 ∼ 8h feeding window, morning or late eating strategies, led to reduction in body weight and fat mass for at least 8 wk. Hence TRE is a potential and effective approach for weight loss for participants with overweight/obesity. An 8h-TRE intervention with a morning eating strategy for at least eight weeks might be the optimum TRE intervention mode.

Although fasting is increasingly applied for disease prevention and treatment, consensus on terminology is lacking. Using Delphi methodology, an international, multidisciplinary panel of researchers and clinicians standardized definitions of various fasting approaches in humans. Five online surveys and a live online conference were conducted with 38 experts, 25 of whom completed all 5 surveys. Consensus was achieved for the following terms: \"fasting\" (voluntary abstinence from some or all foods or foods and beverages), \"modified fasting\" (restriction of energy intake to max. 25% of energy needs), \"fluid-only fasting,\" \"alternate-day fasting,\" \"short-term fasting\" (lasting 2-3 days), \"prolonged fasting\" (≥4 consecutive days), and \"religious fasting.\" \"Intermittent fasting\" (repetitive fasting periods lasting ≤48 h), \"time-restricted eating,\" and \"fasting-mimicking diet\" were discussed most. This study provides expert recommendations on fasting terminology for future research and clinical applications, facilitating communication and cross-referencing in the field.

BACKGROUND: Time-restricted eating (TRE) has been shown to be associated with improvements in some aspects of the metabolic syndrome. Nevertheless, only a few studies have addressed the effect of TRE on pulse wave velocity (PWV). We thus propose a randomized controlled trial to compare the effects of TRE with standard dietary advice on PWV and thereby present the protocol.
METHODS: Forty-eight participants will be assigned to either TRE or control groups using simple randomization. The TRE group will consume their meals during a 10-h period and experience 14 h of fasting. They will also be advised to consume their last meal no later than 20:00. Both groups will receive standard dietary advice. The participants will be followed for 6 weeks. The primary outcome will be changes in PWV. Laboratory measurements, including lipid profile, liver enzyme tests, fasting blood glucose (FBG), insulin concentrations, and insulin resistance, as well as anthropometric data, blood pressure, basal metabolic rate, appetite status, physical activity level, sleep quality, cognitive function, quality of life, and calorie intake, will be evaluated throughout the study.
CONCLUSIONS: The outcomes of this study will allow a comparison of the effects of TRE and standard dietary recommendations on PWV and other cardiometabolic factors in individuals with metabolic syndrome (MetS).
BACKGROUND: Iranian Registry of Clinical Trials; code: IRCT20201230049889N1; registered on August 14, 2022. The registration of the trial is accessible at: https://www.IRCT.ir/trial/64485?revision=281341 .