Effects of time-restricted feeding on body weight, body composition and vital signs in low-income women with obesity: A 12-month randomized clinical trial

The optimal time restricted eating interventions for blood pressure, weight, fat mass, glucose, and lipids: A meta-analysis and systematic review

BACKGROUND

No previous systematic review or meta-analysis has evaluated the effect of optimal time-restricted eating (TRE) interventions on cardiovascular (CVD) risk factors. This meta-analysis aimed to illustrate the effect of a suitable TRE on CVD risk factors.

METHODS

A systematic review was performed to identify trials reporting the effects of TRE, relative to non-diet controls, on CVD risk factors in humans. A random-effects model was used to evaluate the effect sizes, and the results are expressed as the mean difference (MD) and 95% confidence intervals (CIs). Subgroup analyses were performed to examine the influence of the study population, age, duration of intervention, and baseline mean BMI on the CVD indexes.

RESULTS

TRE intervention significantly reduced systolic pressure (SBP) (MD: -3.45 mmHg; 95%CI:(-6.20,-0.71) mmHg; P = 0.01), body weight (MD: -1.63 Kg; 95%CI:(-2.09,-1.17) Kg; P<0.001), body mass index (BMI) (MD: -0.47 Kg/m2; 95% CI: (-0.72, -0.22) Kg/m2; P<0.001), and fat mass (MD: -0.98 Kg; 95% CI: (-1.51,-0.44) Kg; P<0.001), and reduced blood glucose levels. Based on the results of subgroup analysis, this meta-analysis identified the optimal TRE for BP (with a 6 h feeding window, last eating time point at 6-8 PM, and male participants with obesity and aged ≥ 45 years), obesity (with a 6 h feeding window, last eating time point at 6-8 PM, and female participants aged ≥ 45 years), lipids (with an 8 h feeding window, last eating time point at 6-8 PM, and male participants aged < 45 years), and glucose (with a 10-12 h feeding window, last eating time point before 6 PM, and female participants aged < 45years).

CONCLUSIONS

Relative to a non-diet control, TRE is effective for the improvement of CVD risks. Moreover, individual TRE interventions should be developed for different populations to achieve the most effective health improvement for CVD risk factors.

Counting hours or calories? Metabolic regulatory role of time-restricted eating in adults with overweight and obesity: a systematic review and meta-analysis

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.

Unraveling the Health Benefits and Mechanisms of Time-Restricted Feeding: Beyond Caloric Restriction

Time-restricted feeding (TRF) is a lifestyle intervention that aims to maintain a consistent daily cycle of feeding and fasting to support robust circadian rhythms. Recently, it has gained scientific, medical, and public attention due to its potential to enhance body composition, extend lifespan, and improve overall health, as well as induce autophagy and alleviate symptoms of diseases like cardiovascular diseases, type 2 diabetes, neurodegenerative diseases, cancer, and ischemic injury. However, there is still considerable debate on the primary factors that contribute to the health benefits of TRF. Despite not imposing strict limitations on calorie intake, TRF consistently led to reductions in calorie intake. Therefore, while some studies suggest that the health benefits of TRF are primarily due to caloric restriction (CR), others argue that the key advantages of TRF arise not only from CR but also from factors like the duration of fasting, the timing of the feeding period, and alignment with circadian rhythms. To elucidate the roles and mechanisms of TRF beyond CR, this review incorporates TRF studies that did not use CR, as well as TRF studies with equivalent energy intake to CR, which addresses the previous lack of comprehensive research on TRF without CR and provides a framework for future research directions.

Effects of Different Types of Intermittent Fasting Interventions on Metabolic Health in Healthy Individuals (EDIF): A Randomised Trial with a Controlled-Run in Phase

The effects of intermittent fasting (IF) on health promotion in the healthy population remain controversial. Therefore, our study aimed to analyse the efficacy and feasibility of different IF protocols and evaluated the effects within a cohort with a controlled-run in phase on the body mass index (BMI) as the primary outcome, the body composition, and metabolic and haematological markers in healthy participants. A total of 25 individuals were randomised into three fasting groups: 16/8 fasting (n = 11), 20/4 fasting (n = 6), and alternate-day fasting (ADF, n = 8). Assessments were conducted at baseline (visit 1), after a four-week controlled-run in phase (visit 2), and after eight weeks of fasting (visit 3). Both the BMI (p = 0.01) and bodyweight (p = 0.01) were significantly reduced in the ADF group, which was not seen in the 16/8 and 20/4 groups (p > 0.05). Adherence was different but not statistically among the groups (16/8: 84.5 ± 23.0%; 20/4: 92.7 ± 9.5%; and ADF: 78.1 ± 33.5%, p = 0.57). Based on our obtained results, the data suggest that some fasting interventions might be promising for metabolic health. However, adherence to the specific fasting protocols remains challenging even for the healthy population.

Time-Restricted Eating and Bone Health: A Systematic Review with Meta-Analysis

Time-restricted eating (TRE) has emerged as a dietary strategy that restricts food consumption to a specific time window and is commonly applied to facilitate weight loss. The benefits of TRE on adipose tissue have been evidenced in human trials and animal models; however, its impact on bone tissue remains unclear. To systematically synthesize and examine the evidence on the impact of TRE on bone health (bone mineral content (BMC), bone mineral density (BMD), and bone turnover factors), PubMed, Scopus, Cochrane CENTRAL, and Web of Science databases were systematically explored from inception to 1 October 2023 searching for randomized controlled trials (RCTs) aimed at determining the effects of TRE on bone health in adults (≥18 years). The Cochrane Handbook and the PRISMA recommendations were followed. A total of seven RCTs involving 313 participants (19 to 68 years) were included, with an average length of 10.5 weeks (range: 4 to 24 weeks). Despite the significant weight loss reported in five out of seven studies when compared to the control, our meta-analysis showed no significant difference in BMD (g/cm2) between groups (MD = -0.009, 95% CI: -0.026 to 0.009, p = 0.328; I2 = 0%). BMC and bone turnover markers between TRE interventions and control conditions were not meta-analyzed because of scarcity of studies (less than five). Despite its short-term benefits on cardiometabolic health, TRE did not show detrimental effects on bone health outcomes compared to those in the control group. Nevertheless, caution should be taken when interpreting our results due to the scarcity of RCTs adequately powered to assess changes in bone outcomes.

The effect of time of eating on cardiometabolic risk in primary and secondary prevention of cardiovascular disease

Continuous energy restriction is currently considered the first-line dietary therapy for weight loss in individuals with obesity. Recently, interventions which alter the eating window and time of eating occasions have been explored as means to achieve weight loss and other cardiometabolic improvements such as a reduction in blood pressure, glycaemia, lipids and inflammation. It is unknown, however, whether these changes result from unintentional energy restriction or from other mechanisms such as the alignment of nutrient intake with the internal circadian clock. Even less is known regarding the safety and efficacy of these interventions in individuals with established chronic noncommunicable disease states, such as cardiovascular disease. This review examines the effects of interventions which alter both eating window and time of eating occasions on weight and other cardiometabolic risk factors in both healthy participants and those with established cardiovascular disease. We then summarise the state of existing knowledge and explore future directions of study.

A Systematic Review and Meta-Analysis of the Impacts of Time-Restricted Eating on Metabolic Homeostasis

This meta-analysis investigated the effect of time-restricted eating (TRE) as an economical lifestyle intervention for the prevention of metabolic syndrome and improving the related metabolic variables. The Cochrane library, MEDLINE, EMBASE, clinical trials, and other databases were searched for randomized controlled trials (RCTs). We included 22 RCTs (1004 participants, aged 18-75 years, including healthy subjects, prediabetes and overweight patients) designed to evaluate the effect of TRE on metabolic parameters. Body mass index (BMI) (-0.56 kg/m2, 95% CI: -1.00, -0.13, P < .01), fasting blood glucose (-1.74 mmol/L, 95% CI: -3.34, -0.14, P < .01), and body weight (-0.48 kg, 95% CI: -0.74, -0.22, P < .01) in the TRE intervention group were decreased to varying degrees compared with controls. In contrast, high-density lipoprotein cholesterol (HDL-C) levels were significantly increased in the TRE group compared with the control group (P < .01). The change in waist circumference, blood pressure, triglycerides, low-density lipoprotein cholesterol (LDL-C), and total cholesterol did not vary markedly across the groups. In conclusion, this meta-analysis found a significant reduction in BMI, weight, and fasting glucose, as well as a rise in HDL-C level with TRE compared with control. TRE could be used as an adjuvant treatment for metabolic dysfunctions.

Effects of Intermittent Energy Restriction Compared with Those of Continuous Energy Restriction on Body Composition and Cardiometabolic Risk Markers - A Systematic Review and Meta-Analysis of Randomized Controlled Trials in Adults

The interest in intermittent energy restriction (IER) diets as a weight-loss approach is increasing. Different IER protocols exist, including time-restricted eating (TRE), alternate-day fasting (ADF), and the 5:2 diet. This meta-analysis compared the effects of these IER diets with continuous energy restriction (CER) on anthropometrics and cardiometabolic risk markers in healthy adults. Twenty-eight trials were identified that studied TRE (k = 7), ADF (k = 10), or the 5:2 diet (k = 11) for 2-52 wk. Energy intakes between intervention groups within a study were comparable (17 trials), lower in IER (5 trials), or not reported (6 trials). Weighted mean differences (WMDs) were calculated using fixed- or random-effects models. Changes in body weight [WMD: -0.42 kg; 95% confidence interval (CI): -0.96 to 0.13; P = 0.132] and fat mass (FM) (WMD: -0.31 kg; 95% CI: -0.98 to 0.36; P = 0.362) were comparable when results of the 3 IER diets were combined and compared with those of CER. All IER diets combined reduced fat-free mass (WMD: -0.20 kg; 95% CI: -0.39 to -0.01; P = 0.044) and waist circumference (WMD: -0.91 cm; 95% CI: -1.76 to -0.06; P = 0.036) more than CER. Effects on body mass index [BMI (kg/m2)], glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), serum lipid and lipoprotein concentrations, and blood pressure did not differ. Further, TRE reduced body weight, FM, and fat-free mass more than CER, whereas ADF improved HOMA-IR more. BMI was reduced less in the 5:2 diet compared with CER. In conclusion, the 3 IER diets combined did not lead to superior improvements in anthropometrics and cardiometabolic risk markers compared with CER diets. Slightly greater reductions were, however, observed in fat-free mass and waist circumference. To what extent differences in energy intakes between groups within studies may have influenced these outcomes should be addressed in future studies.

Time-restricted eating with calorie restriction on weight loss and cardiometabolic risk: a systematic review and meta-analysis

The effect of time-restricted eating (TRE) has been summarized in previous studies, but its benefits in combination with calorie restriction (CR) still need to be determined. The present meta-analysis aimed to evaluate the efficacy of TRE with CR on weight loss and cardiometabolic risk. PubMed, Embase, Cochrane Library, and gray literature databases were searched from inception to October 18, 2022, for potential randomized controlled trial (RCT) studies based on predefined inclusion and exclusion criteria. Body weight and other cardiometabolic risk factors were described as weighted mean difference (WMD) with a 95% confidence interval (CI). Eight RCTs involving 579 participants were enrolled in the present analysis. The pooled results showed that TRE with CR reduced the body weight, fat mass, and waist circumference significantly (WMD: -1.40, 95% CI: -1.81 to -1.00, and I2: 0%; WMD: -0.73, 95% CI: -1.39 to -0.07, and I2: 0%; WMD: -1.87, 95% CI: -3.47 to -0.26, and I2: 67.25%, respectively). However, compared with CR alone, TRE plus CR exhibited no significant benefit on the blood pressure, glucose profile, and lipid profile. Subgroup analysis suggested that early TRE is more effective in weight loss (WMD: -1.42, 95% CI: -1.84 to -1.01, and I2: 0%) and improving fat mass (WMD: -1.06, 95% CI: -1.91 to -0.22, and I2: 0%) than delayed or broader TRE when combined with CR. Although the combination of TRE and CR can effectively decrease body weight, fat mass, and waist circumference, the long-term effects, particularly those on cardiometabolic risk in participants with chronic cardiovascular disease and diabetes, remain to be explored.

An alternative approach to obesity treatment: intermittent fasting

Overweight and obesity are an important public health problem that affects a significant part of the world population and increases the risk of many metabolic diseases. Weight loss is the primary goal in obesity treatment, and many different dietary interventions are tried for this purpose. Intermittent fasting is a diet that has become popular in recent years with the weight loss it provides and includes periods of fasting and feeding. In addition to providing weight loss, intermittent fasting also has positive effects on important risk factors such as glucoregulatory parameters, blood lipids, and oxidative stress. Intermittent fasting appears to be an effective and safe way to achieve weight loss in obesity. It could also have therapeutic effects on obesity-related diseases. The aim of this review was to bring together up-to-date information on the effects of intermittent fasting on obesity and various obesity-related diseases, mechanisms of action, possible benefits and harms, and potential uses.

Umbrella review of time-restricted eating on weight loss, fasting blood glucose, and lipid profile

CONTEXT

A growing number of systematic reviews with meta-analyses have examined the effectiveness of time-restricted eating (TRE) in reducing weight and improving fasting blood glucose and lipid profiles. However, mixed results have been found, and its effectiveness remains uncertain.

OBJECTIVE

This umbrella review aimed to summarize systematic reviews that (1) examine the effects of TRE on weight loss, fasting blood glucose, total cholesterol, triglycerides, high-density-lipoprotein cholesterol (HDL-C) and low-density-lipoprotein cholesterol (LDL-C) in individuals with overweight and obesity; and (2) compare the effect sizes on these outcomes between conventional TRE and Ramadan fasting.

DATA SOURCES

A total of 11 databases were searched from inception until March 11, 2022.

DATA EXTRACTION

Two independent reviewers performed article selection, data extraction, and quality assessment.

DATA ANALYSIS

Seven systematic reviews with 30 unique meta-analyses involving 7231 participants from 184 primary studies were included. The quality of each review was evaluated as moderate (14.3%) or critically low (85.7%) according to the Assessment of Multiple Systematic Reviews 2. The degree of overlap was rated as slight for all outcomes (corrected cover area = 1.04%-4.27%). Meta-analyses at the meta-data level suggest that TRE is beneficial for reducing weight (P = .006) and fasting blood glucose (P < .01). Meta-analyses at the primary study level suggest that the effect on LGL-C was significant (P = .03). Subgroup analyses revealed greater effects in lowering fasting blood glucose, total cholesterol, and LDL-C from Ramadan fasting than from conventional TRE. The credibility of evidence was rated as suggestive (3.3%), weak (36.7%) or nonsignificant (60%) using a classification method.

CONCLUSION

TRE may complement usual care and reduce body weight and fasting blood glucose. Rigorous randomized controlled trials with long-term assessments in a wide range of populations are warranted.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022325657.

Effectiveness of intermittent fasting for weight loss in individuals with obesity: A meta-analysis of randomized controlled trials

AIM

To assess whether intermittent fasting (IF) diets are associated with improvement in weight loss, metabolic parameters, and subjective well-being, in people with obesity.

DATA SYNTHESIS

We performed a Meta-analysis of Randomized Controlled Trials longer than 2 months, retrieved through an extensive search on MedLine, Cochrane CENTRAL Library, and Embase online databases, comparing weight loss with IF diets and control diets in people with Body Mass index (BMI) > 30 kg/m². We retrieved 9 trials, enrolling 540 patients. IF was not associated with a significantly greater reduction of body weight or BMI at any time point with respect to controls or in respect to continuous restricted diets, with low-to moderate quality of evidence; no significant difference in efficacy between alternate day fasting and time restricted eating was found. Differences in fasting plasma glucose, total or high-density lipoprotein cholesterol or blood pressure at any time point were not statistically significant, whereas a reduction of low-density lipoprotein cholesterol (MD -8.39 [-15.96, -0.81] mg/dl, P = 0.03; I² = 0%) was observed at 2-4 months, but not in the longer term. Data on psychological parameters and overall well-being were insufficient to perform a formal meta-analysis, whereas a qualitative synthesis did not show any difference between IF and controls.

CONCLUSIONS

IF is not associated with greater or lesser weight loss than non-intermittent fasting diets. Further data on psychological parameters and overall well-being are needed to properly assess the role of IF diets in the management of obesity.

Effects of time-restricted eating with different eating duration on anthropometrics and cardiometabolic health: A systematic review and meta-analysis

BACKGROUND

Time-restricted eating (TRE) is a dietary approach that limits eating to a set number of hours per day. Human studies on the effects of TRE intervention on cardiometabolic health have been contradictory. Heterogeneity in subjects and TRE interventions have led to inconsistency in results. Furthermore, the impact of the duration of eating/fasting in the TRE approach has yet to be fully explored.

AIM

To analyze the existing literature on the effects of TRE with different eating durations on anthropometrics and cardiometabolic health markers in adults with excessive weight and obesity-related metabolic diseases.

METHODS

We reviewed a series of prominent scientific databases, including Medline, Scopus, Web of Science, Academic Search Complete, and Cochrane Library articles to identify published clinical trials on daily TRE in adults with excessive weight and obesity-related metabolic diseases. Randomized controlled trials were assessed for methodological rigor and risk of bias using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB-2). Outcomes of interest include body weight, waist circumference, fat mass, lean body mass, fasting glucose, insulin, HbA1c, homeostasis model assessment for insulin resistance (HOMA-IR), lipid profiles, C-reactive protein, blood pressure, and heart rate.

RESULTS

Fifteen studies were included in our systematic review. TRE significantly reduces body weight, waist circumference, fat mass, lean body mass, blood glucose, insulin, and triglyceride. However, no significant changes were observed in HbA1c, HOMA-IR, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, heart rate, systolic and diastolic blood pressure. Furthermore, subgroup analyses based on the duration of the eating window revealed significant variation in the effects of TRE intervention depending on the length of the eating window.

CONCLUSION

TRE is a promising chrononutrition-based dietary approach for improving anthropometric and cardiometabolic health. However, further clinical trials are needed to determine the optimal eating duration in TRE intervention for cardiovascular disease prevention.

Effects of Intermittent Fasting on Regulation of Metabolic Homeostasis: A Systematic Review and Meta-Analysis in Health and Metabolic-Related Disorders

Intermittent fasting (IF) is an emerging dietetic intervention that has been associated with improved metabolic parameters. Nowadays, the most common IF protocols are Alternate-Day Fasting (ADF) and Time-Restricted Fasting (TRF), but in this review and meta-analysis we have also considered Religious Fasting (RF), which is similar to TRF but against the circadian rhythm. The available studies usually include the analysis of a single specific IF protocol on different metabolic outcomes. Herein, we decided to go further and to conduct a systematic review and meta-analysis on the advantages of different IF protocols for metabolic homeostasis in individuals with different metabolic status, such as with obesity, diabetes mellitus type 2 (T2D) and metabolic syndrome (MetS). Systematic searches (PubMed, Scopus, Trip Database, Web of Knowledge and Embase, published before June 2022) of original articles in peer-review scientific journals focusing on IF and body composition outcomes were performed. Sixty-four reports met the eligibility criteria for the qualitative analysis and forty-seven for the quantitative analysis. Herein, we showed that ADF protocols promoted the major beneficial effects in the improvement of dysregulated metabolic conditions in comparison with TRF and RF protocols. Furthermore, obese and MetS individuals are the most benefited with the introduction of these interventions, through the improvement of adiposity, lipid homeostasis and blood pressure. For T2D individuals, IF impact was more limited, but associated with their major metabolic dysfunctions-insulin homeostasis. Importantly, through the integrated analysis of distinct metabolic-related diseases, we showed that IF seems to differently impact metabolic homeostasis depending on an individual's basal health status and type of metabolic disease.

Fasting: From Physiology to Pathology

Overnutrition is a risk factor for various human diseases, including neurodegenerative diseases, metabolic disorders, and cancers. Therefore, targeting overnutrition represents a simple but attractive strategy for the treatment of these increasing public health threats. Fasting as a dietary intervention for combating overnutrition has been extensively studied. Fasting has been practiced for millennia, but only recently have its roles in the molecular clock, gut microbiome, and tissue homeostasis and function emerged. Fasting can slow aging in most species and protect against various human diseases, including neurodegenerative diseases, metabolic disorders, and cancers. These centuried and unfading adventures and explorations suggest that fasting has the potential to delay aging and help prevent and treat diseases while minimizing side effects caused by chronic dietary interventions. In this review, recent animal and human studies concerning the role and underlying mechanism of fasting in physiology and pathology are summarized, the therapeutic potential of fasting is highlighted, and the combination of pharmacological intervention and fasting is discussed as a new treatment regimen for human diseases.

Metabolic and behavioral effects of time-restricted eating in women with overweight or obesity: Preliminary findings from a randomized study

OBJECTIVES

The aim of this study was to evaluate the effects of 8 wk of time-restricted eating (TRE) along with a caloric restriction on metabolic profile, metabolic rate, symptoms of mood, and eating disorders and weight loss in women with overweight or obesity.

METHODS

Women age 18 to 59 y with a body mass index of ≥25 kg/m² were enrolled in this parallel-arm, randomized, clinical trial. Participants were randomly allocated into two groups (8-h TRE or non-TRE group) using a 2:1 allocation strategy. Both groups received a diet plan with caloric restriction. Body weight, resting metabolic rate, metabolic profile, and symptoms of mood and eating disorders were evaluated at baseline and on follow up.

RESULTS

Thirty-six subjects were included in this study, with 24 in the TRE group and 12 in the non-TRE group. Subject in the TRE group showed more pronounced loss of weight, body fat mass, and fat-free mass than those in the non-TRE group. These losses were not associated with changes in resting metabolic rate, metabolic profile, and eating or mood disorder symptoms.

CONCLUSIONS

This study showed that 8 wk of TRE does not influence behavioral parameters in individuals with overweight or obesity, but could lead to weight loss.

Effects of Time-Restricted Eating on Nonalcoholic Fatty Liver Disease: The TREATY-FLD Randomized Clinical Trial

IMPORTANCE

The efficacy and safety of time-restricted eating (TRE) on nonalcoholic fatty liver disease (NAFLD) remain uncertain.

OBJECTIVE

To compare the effects of TRE vs daily calorie restriction (DCR) on intrahepatic triglyceride (IHTG) content and metabolic risk factors among patients with obesity and NAFLD.

DESIGN, SETTING, AND PARTICIPANTS

This 12-month randomized clinical trial including participants with obesity and NAFLD was conducted at the Nanfang Hospital in Guangzhou, China, between April 9, 2019, and August 28, 2021.

INTERVENTIONS

Participants with obesity and NAFLD were randomly assigned to TRE (eating only between 8:00 am and 4:00 pm) or DCR (habitual meal timing). All participants were instructed to maintain a diet of 1500 to 1800 kcal/d for men and 1200 to 1500 kcal/d for women for 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in IHTG content measured by magnetic resonance imaging; secondary outcomes were changes in body weight, waist circumference, body fat, and metabolic risk factors. Intention-to-treat analysis was used.

RESULTS

A total of 88 eligible patients with obesity and NAFLD (mean [SD] age, 32.0 [9.5] years; 49 men [56%]; and mean [SD] body mass index, 32.2 [3.3]) were randomly assigned to the TRE (n = 45) or DCR (n = 43) group. The IHTG content was reduced by 8.3% (95% CI, -10.0% to -6.6%) in the TRE group and 8.1% (95% CI, -9.8% to -6.4%) in the DCR group at the 6-month assessment. The IHTG content was reduced by 6.9% (95% CI, -8.8% to -5.1%) in the TRE group and 7.9% (95% CI, -9.7% to -6.2%) in the DCR group at the 12-month assessment. Changes in IHTG content were comparable between the 2 groups at 6 months (percentage point difference: -0.2; 95% CI, -2.7 to 2.2; P = .86) and 12 months (percentage point difference: 1.0; 95% CI, -1.6 to 3.5; P = .45). In addition, liver stiffness, body weight, and metabolic risk factors were significantly and comparably reduced in both groups.

CONCLUSIONS AND RELEVANCE

Among adults with obesity and NAFLD, TRE did not produce additional benefits for reducing IHTG content, body fat, and metabolic risk factors compared with DCR. These findings support the importance of caloric intake restriction when adhering to a regimen of TRE for the management of NAFLD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT03786523 and NCT04988230.

Circadian-mediated regulation of cardiometabolic disorders and aging with time-restricted feeding

Circadian rhythms are present throughout biology, from the molecular level to complex behaviors such as eating and sleeping. They are driven by molecular clocks within cells, and different tissues can have unique rhythms. Circadian disruption can trigger obesity and other common metabolic disorders such as aging, diabetes, and cardiovascular disease, and circadian genes control metabolism. At an organismal level, feeding and fasting rhythms are key drivers of circadian rhythms. This underscores the bidirectional relationship between metabolism and circadian rhythms, and many metabolic disorders have circadian disruption or misalignment. Therefore, studying circadian rhythms may offer new avenues for understanding the etiology and management of obesity. This review describes how circadian rhythm dysregulation is linked with cardiometabolic disorders and how the lifestyle intervention of time-restricted feeding (TRF) regulates them. TRF reinforces feeding-fasting rhythms without reducing caloric intake and ameliorates metabolic disorders such as obesity and associated cardiac dysfunction, along with reducing inflammation. TRF optimizes the expression of genes and pathways related to normal metabolic function, linking metabolism with TRF's benefits and demonstrating the molecular link between metabolic disorders and circadian rhythms. Thus, TRF has tremendous therapeutic potential that could be easily adopted to reduce obesity-linked dysfunction and cardiometabolic disorders.

The Effects of Isocaloric Intermittent Fasting vs Daily Caloric Restriction on Weight Loss and Metabolic Risk Factors for Noncommunicable Chronic Diseases: A Systematic Review of Randomized Controlled or Comparative Trials

BACKGROUND

Intermittent fasting (IF) has gained favor as an alternative regimen to daily caloric restriction (DCR). Therefore, there is a need for systematic reviews of randomized controlled/comparison trials examining the effects of isocaloric IF vs DCR on metabolic risk factors for noncommunicable chronic diseases.

OBJECTIVE

To systematically investigate the effects of isocaloric IF vs DCR on metabolic risk factors for noncommunicable chronic diseases in adults with overweight and obesity.

METHODS

Five online databases (PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar) were searched for articles published from January 2000 through April 2022. The updated Cochrane Risk of Bias Assessment tool for randomized controlled/comparison trials was used to assess risk of bias in the included studies. This review includes randomized controlled/comparison trials with matched energy intakes (isocaloric) between IF and DCR among adults with overweight and obesity with ≥8-week durations, that assessed risk factors related to obesity and for diabetes, cardiovascular diseases, and cancers.

RESULTS

Thirteen randomized controlled/comparison trials with matched energy intakes (isocaloric) between IF and DCR were identified. The effects of IF on weight loss and metabolic risk markers of diabetes, cardiovascular diseases, and cancers were varied but generally comparable with DCR. IF (4:3 and 5:2 diets) was superior to DCR for improving insulin sensitivity in two studies. Reductions in body fat were significantly greater with IF (5:2 diet and time-restricted eating) than DCR in two studies of isocaloric diets.

CONCLUSIONS

With matched energy intakes, IF interventions produced similar beneficial effects for weight loss and chronic disease risk factors compared with DCR. Very limited evidence suggests that IF may be more effective vs DCR for fat loss and insulin sensitivity, but conclusions cannot be drawn based on the current evidence. Future clinical studies with larger populations and longer durations are needed for further elucidation of any potential effects of IF regimens for prevention of noncommunicable chronic diseases.

Health effects of the time-restricted eating in adults with obesity: A systematic review and meta-analysis

Background

The number of people suffering from overweight or obesity has been steadily increasing in recent years. As a new form of diet, the efficacy of time-restricted eating (TRE) remains debatable.

Objective

This meta-analysis quantified the effect of TRE on weight change and other physical parameters in obese and overweight adults.

Methods

We did a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the TRE interventions on weight loss and other metabolic parameters by searching PubMed, Embase, and Cochrane Central Register of Controlled Trials to identify eligible trials published from database inception up until 23 August 2022. The risk of bias was assessed using the Revised Cochrane risk-of-bias tool (ROB-2.0). Meta-analysis was performed using Review Manager 5.4.1 software.

Results

Nine RCTs with 665 individuals (345 in the TRE group while 320 in the control group) were included. Results indicated that TRE had a greater decrease in body weight (-1.28 kg; 95% CI [-2.05, -0.52], p = 0.001), fat mass (-0.72 kg; 95% CI [-1.40, -0.03], p = 0.04), body mass index (-0.34 kg/m²; 95% CI [-0.64, -0.04], p = 0.03) and diastolic blood pressure (-2.26 mmHg 95% CI [-4.02, -0.50], p = 0.01). However, the meta-analysis demonstrated that there was no significant difference between TRE and the control group in lean mass, systolic blood pressure, waist circumference, fasting glucose, fasting insulin, homeostasis model assessment-insulin resistance (HOMA-IR), total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides. Besides, the duration of the study and daily eating window also had an impact on weight change.

Conclusion

TRE was associated with reductions in weight and fat mass and can be a dietary intervention option for adults with obesity. But high-quality trials and longer follow-ups are needed to draw definitive conclusions.

Adherence to Mediterranean Diet and Response to an Exercise Program to Prevent Hospitalization-Associated Disability in Older Adults: A Secondary Analysis from a Randomized Controlled Trial

OBJECTIVES

To investigate the relationship between Mediterranean diet (MedDiet) adherence and response to an exercise and health education program to prevent hospitalization-associated disability (HAD) in acutely hospitalized older adults.

DESIGN

Randomized controlled trial.

SETTING AND PARTICIPANTS

Secondary analysis of a subset of 109 participants from AGECAR-PLUS study with available data on MedDiet adherence (mean age 87, and range 75-98).

INTERVENTION

Participants were randomized into the control group (n = 46, usual care) or the intervention group (n = 63, supervised exercise and health education) at admission.

MEASUREMENTS

MedDiet adherence was measured with MEDAS and through urinary total polyphenols (UTP). Functional status was assessed with the Barthel Index.

RESULTS

At discharge, patients in the intervention group who had low levels of MedDiet or UTP showed an increase in functional status [adjusted mean (95% CI) = 77.8 (70.8-84.8) points, p = 0.005, and adjusted mean (95% CI) = 78.0 (68.3-87.7) points, p = 0.020, respectively].

CONCLUSION

Older individuals over age 75 with low MedDiet adherence were likely to benefit more from a physical exercise and health education intervention.

Metabolic Efficacy of Time-Restricted Eating in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

CONTEXT

Time-restricted eating (TRE), which restricts food intake to a limited duration of the day, is a key regimen of intermittent fasting.

OBJECTIVE

The aim of our study was to provide an up-to-date meta-analysis and systematic review to evaluate the efficacy of TRE on weight loss and other metabolic-related parameters in adults.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library for relevant studies published before February 26, 2022. Study duration of TRE was at least 4 weeks. Body weight and other metabolic-related continuous parameters were described as weighted mean difference (WMD) with 95% CI.

RESULTS

Seventeen randomized controlled trials involving 899 participants were analyzed. The pooled meta-analysis has shown that TRE contributed to a significant decrease in body weight with a WMD of -1.60 kg (95% CI -2.27 to -0.93) and fat mass with WMD -1.48 kg (95% CI -1.59 to -1.38). Subgroup analysis showed that TRE could reduce body weight and fat mass especially in overweight participants with WMD -1.43 kg (95% CI -2.05 to -0.81) and -1.56 kg (95% CI -1.67 to -1.44), respectively. TRE also showed beneficial effects on the lipid spectrum in overweight participants, including decreased levels of triglyceride (WMD -12.71 mg/dL, 95% CI -24.9 to -0.52), total cholesterol (WMD -6.45 mg/dL, 95% CI -7.40 to -5.49), and low-density lipoprotein cholesterol (WMD -7.0 mg/dL, 95% CI -9.74 to -4.25). However, compared with control, TRE had no significant effects on waist circumference, body mass index, glycosylated hemoglobin, or blood pressure.

CONCLUSION

This updated meta-analysis found that TRE may be an effective approach to improve the metabolic state of nonobese subjects, especially in overweight participants.

Effects of an Intermittent Fasting 5:2 Plus Program on Body Weight in Chinese Adults with Overweight or Obesity: A Pilot Study

To retrospectively review the efficacy of intermittent fasting 5:2 plus program (30% of energy requirements on fast days and 70% of energy requirements on nonfasting days) in Chinese patients with overweight or obesity. This retrospective cohort study evaluated weight loss outcomes of patients treated with 12 weeks weight loss program in clinic. Adults with overweight or obesity participated in intermittent fasting 5:2 plus, daily calorie restriction (70% of energy requirements every day) or daily calorie restriction with meal replacement (70% of energy requirements every day, partly provided with high-protein meal replacement) programs for 12 weeks. The primary objective was to compare the weight loss of three groups. The primary outcome measure was the change in the % total weight loss. A total of 131 patients (35.3 ± 10.1 years; 81.7% female) were included, and the mean weight loss was 7.8 ± 4.4% after 12 weeks. The intermittent fasting 5:2 plus group (n = 42) achieved 9.0 ± 5.3% weight loss, compared with 5.7 ± 3.7% in the daily calorie restriction group (n = 41) (p < 0.001) and 8.6 ± 3.5% in the meal replacement group (n = 48) (p = 0.650). A total of 85.7% of patients in the intermittent fasting 5:2 plus group lost more than 5% body weight, vs. 58.5% in the daily calorie restriction group (p = 0.008), and 45.2% lost more than 10% body weight, vs. 14.6% in the daily calorie restriction group (p = 0.005). No serious adverse events were reported in the three groups. The intermittent fasting 5:2 plus program more effectively led to weight loss than daily calorie restriction in the short-term in Chinese patients with overweight or obesity. A longer-term prospective randomized controlled trial is needed.

Beneficial effect of time-restricted eating on blood pressure: a systematic meta-analysis and meta-regression analysis

Background

As a cardiometabolic disease, hypertension has shown an obvious upward trend, becoming a global epidemic chronic disease. Lifestyle intervention is a fundamental method for lowering blood pressure. This systematic review and meta-analysis aimed to evaluate the effects of time-restricted eating (TRE) on blood pressure.

Methods

Studies were retrieved from the PubMed, Embase, Cochrane Library, and Web of Science databases to evaluate the effects of TRE on blood pressure. The time frame of search was from the start of database construction until July 14, 2022.There were no language restrictions. Meta-analysis and meta-regression were performed using Stata version 16. The weighted mean difference with 95% CI was used to assess the effect of TRE on blood pressure, heart rate, weight, blood glucose, total cholesterol, HDL-C, LDL-C, and triglycerides. The main ending of this article were blood pressure and heart rate, while the secondary ending were weight, blood glucose, total cholesterol, HDL-C, LDL-C, and triglycerides.

Results

Ten randomized controlled trials involving 694 patients were identified. TRE significantly reduced systolic blood pressure (SBP) (mean difference = −4.15; 95% CI: −6.73, −2.30; P < 0.0001), but had no significant effect on diastolic blood pressure (DBP) (mean difference = −2.06; 95% CI: −4.16, 0.02; P = 0.053) and no beneficial effect on heart rate (mean difference = 0.36; 95% CI: −2.83, 3.54; P = 0.0825). TRE promoted weight loss (mean difference = −1.63; 95% CI: −2.61, −0.64; P = 0.001) and decreased blood glucose levels (mean difference = −2.80; 95% CI: −4.64, −0.96; P = 0.003), but had no significant effect on total cholesterol (mean difference = 0.03, 95% CI: −10.01, 10.08; P = 0.995), HDL-C (mean difference = 0.85, 95% CI: −1.80, 3.49; P = 0.531), LDL-C (mean difference = −0.86, 95% CI: −6.47, 4.76; P = 0.764), or triglycerides (mean difference = −3.524, 95% CI: −9.49, 2.45; P = 0.248). In a separate meta-regression analysis, the degree of SBP change was related to weight loss (P = 0.044) but not to glucose improvement (P = 0.867).

Conclusions

The present meta-analysis suggests that TRE significantly reduced SBP, while no effect of reducing DBP was seen. The observed lower blood pressure may be attributed to significant weight loss. The effects of TRE on heart rate and blood lipid levels were not apparent.

Effects of weight loss through lifestyle changes on heart rate variability in overweight and obese patients: A systematic review

BACKGROUND & AIMS

The effects of calorie restriction and physical activity on autonomic regulation and cardiac vagal control in overweight and obese individuals remain inconsistent. Thus, this systematic review aimed to evaluate the weight loss effects through lifestyle changes on heart rate variability (HRV) markers in overweight and obese subjects.

METHODS

A systematic search for studies published up to November 2021 was conducted in MEDLINE, Embase, EBSCO host and VHL REGIONAL/LILACS. The main outcomes were changes in HRV indices from pre- and post-nutritional intervention and exercise in overweight and obese individuals. This review was registered in PROSPERO: CRD42021274467.

RESULTS

The literature search retrieved 959 articles, of which 12 were included in this review. The intervention in nine studies was diet only, in two studies was diet and exercise, and in one study diet was compared to diet and exercise. The weight loss was greater than 10% in four studies and between 5 and 10% in three studies. Most of the studies revealed that weight loss through lifestyle changes seems to promote beneficial effects on HRV, restoring sympathovagal balance by increasing parasympathetic activity and reducing sympathetic activation.

CONCLUSION

This systematic review exhibited the beneficial effects of weight loss through lifestyle changes on cardiac autonomic control in overweight and obese individuals. Future investigations need standardization of HRV indices for better interpretation of autonomic function in different clinical situations.

Complex physiology and clinical implications of time-restricted eating

Time-restricted eating (TRE) is a dietary intervention that limits food consumption to a specific time window each day. The effect of TRE on body weight and physiological functions has been extensively studied in rodent models, which have shown considerable therapeutic effects of TRE and important interactions among time of eating, circadian biology, and metabolic homeostasis. In contrast, it is difficult to make firm conclusions regarding the effect of TRE in people because of the heterogeneity in results, TRE regimens, and study populations. In this review, we 1) provide a background of the history of meal consumption in people and the normal physiology of eating and fasting; 2) discuss the interaction between circadian molecular metabolism and TRE; 3) integrate the results of preclinical and clinical studies that evaluated the effects of TRE on body weight and physiological functions; 4) summarize other time-related dietary interventions that have been studied in people; and 4) identify current gaps in knowledge and provide a framework for future research directions.

Insulin-Lowering Diets in Metastatic Cancer

Hyperinsulinemia is an independent risk factor for cancer mortality. Insulin-lowering dietary strategies such as calorie restriction (CR), low-carbohydrate or ketogenic diets (KD), and intermittent fasting (IF) are aimed at reducing systemic stores of nutrients utilized by cancer cells, attenuating insulin-related growth signaling, and improving obesity-related metabolic parameters. In this narrative review, we searched the published literature for studies that tested various insulin-lowering diets in metastatic cancer in preclinical and clinical settings. A total of 23 studies were identified. Of these, 14 were preclinical studies of dietary strategies that demonstrated improvements in insulin levels, inhibition of metastasis, and/or reduction in metastatic disease burden in animal models. The remaining nine clinical studies tested carbohydrate restriction, KD, or IF strategies which appear to be safe and feasible in patients with metastatic cancer. These approaches have also been shown to improve serum insulin and other metabolic parameters. Though promising, the anti-cancer efficacy of these interventions, such as impact on tumor response, disease-specific-, and overall survival, have not yet been conclusively demonstrated. Studies that are adequately powered to evaluate whether insulin-lowering diets improve cancer outcomes are warranted.

Bibliometric and visual analysis of time-restricted eating

An increasing number of studies have shown the effects of time-restricted eating (TRE) on metabolic diseases and cardiovascular diseases associated with obesity. However, no bibliometric analyses were conducted in this field systematically. In our study, we aimed to visualize the publications about TRE to determine the frontiers and hotspots and then provide references and guidance for further studies. Publications about TRE were exported from the Web of Science Core Collection (WOSCC) database. VOSviewer 1.6.16 was adopted to perform the bibliometric analysis. In our study, a total of 414 publications with 298 articles and 116 reviews were included. The publications in this field showed an upward trend from 2016. A total of 2016 authors contributed to this field. The most productive authors were Satchidananda Panda, Krista A Varady and Emily NC Manoogian. All publications were distributed from about 624 organizations from 49 Countries/Regions. The leading institutions were the Salk Institute for Biological Studies, the University of California San Diego and the University of Alabama at Birmingham, and the most productive countries were the United States, the People’s Republic of China and Japan. All publications were from 182 journals, and the most productive journals were Nutrients, Frontiers in Nutrition and Cell Metabolism. The first highest cited reference with 991 citations was published in Cell Metabolism, and authored by Satchidananda Panda et al. There were four indicating research directions, and the keywords of the green cluster were time-restricted feeding, metabolism, circadian clock, and circadian rhythm. The keywords of the blue cluster were obesity, health, diet, and food intake. The keywords of the red cluster were intermittent fasting, weight loss, caloric restriction, and time-restricted eating. The keywords of the yellow cluster were insulin resistance, metabolic disease, cardiovascular disease, and caloric intake. The main research hotspots in the TRE field were TRE and circadian rhythm, TRE and obesity, TRE and metabolic disease, and TRE and cardiovascular disease. TRE represents new directions to evaluate the effects of the timing of eating on different diseases, especially obesity, Type 2 diabetes mellitus and cardiovascular disease. Previous studies have generated impressive data on the effects of TRE on metabolic diseases and cardiovascular diseases associated with obesity. More high-quality studies are needed to assess the mechanism and efficacy of TRE in a wide range of populations and diseases.

Association between statins exposure with incidence and prognosis of gastric cancer: an updated meta-analysis

BACKGROUND AND AIMS

Previous research has revealed the role of statins in cancer prevention and treatment. This study aimed to determine the relationship between statins exposure and the incidence and prognosis of gastric cancer (GC).

METHODS

Relevant articles until January 2022 were systematically searched in PubMed, EBSCO, Web of Science, and Cochrane Library databases for comparison in GC with or without statins exposure. The primary referred outcomes were the occurrence of GC and the survival rate. A total of 19 articles were included in this meta-analysis.

RESULTS

The analysis showed that statins were associated with reduced GC incidence and increased GC survival rate. Subgroup analysis suggested a decreased incidence of GC in both Eastern and Western countries exposed to statins. Furthermore, the risk of GC was reduced in those exposed to lipophilic statins, yet not in those exposed to hydrophilic statins.

CONCLUSIONS

Statins were found to help lower the incidence and improve the survival rate of GC. Furthermore, the incidence of GC was influenced by the population's origin region and the type of statins used.

Developing dietary interventions as therapy for cancer

Cancer cells acquire distinct metabolic preferences based on their tissue of origin, genetic alterations and degree of interaction with systemic hormones and metabolites. These adaptations support the increased nutrient demand required for increased growth and proliferation. Diet is the major source of nutrients for tumours, yet dietary interventions lack robust evidence and are rarely prescribed by clinicians for the treatment of cancer. Well-controlled diet studies in patients with cancer are rare, and existing studies have been limited by nonspecific enrolment criteria that inappropriately grouped together subjects with disparate tumour and host metabolic profiles. This imprecision may have masked the efficacy of the intervention for appropriate candidates. Here, we review the metabolic alterations and key vulnerabilities that occur across multiple types of cancer. We describe how these vulnerabilities could potentially be targeted using dietary therapies including energy or macronutrient restriction and intermittent fasting regimens. We also discuss recent trials that highlight how dietary strategies may be combined with pharmacological therapies to treat some cancers, potentially ushering a path towards precision nutrition for cancer.

Cardiometabolic effects of early v. delayed time-restricted eating plus energetic restriction in adults with overweight and obesity: an exploratory randomised clinical trial

This exploratory study investigated the effects of early v. delayed time-restricted eating (TRE) plus caloric restriction (CR) on body weight, body composition and cardiometabolic parameters in adults with overweight and obesity. Adults (20-40 years) were randomised to one of three groups for 8 weeks: early time-restricted eating (eTRE; 08.00-16.00) plus CR, delayed time-restricted eating (dTRE; 12.00-20.00) plus CR or only CR (CR; 08.00-20.00). All groups were prescribed a 25 % energy deficit relative to daily energy requirements. Thirteen participants completed the study in the eTRE and CR groups and eleven in the dTRE group (n 37). After the interventions, there was no significant difference between the three groups for any of the outcomes. Compared with baseline, significant decreases were observed in the body weight (eTRE group: -4·2 kg; 95 % CI, -5·6, -2·7; dTRE group: -4·8 kg; 95 % CI, -5·9, -3·7; CR: -4·0 kg; 95 % CI, -5·9, -2·1), fat mass (eTRE group: -2·9 kg; 95 % CI, -3·9, -1·9; dTRE group: -3·6 kg; 95 % CI, -4·6, -2·5; CR: -3·1 kg; 95 % CI, -4·3, -1·8) and fasting glucose levels (eTRE group: -4 mg/dl; 95 % CI, -8, -1; dTRE group: -2 mg/dl; 95 % CI, -8, 3; CR: -3 mg/dl; 95 % CI, -8, 2). In a free-living setting, TRE with a energetic deficit, regardless of the time of day, promotes similar benefits in weight loss, body composition and cardiometabolic parameters. However, given the exploratory nature of our study, further investigation is needed to confirm these findings.

Effects of Intermittent Fasting in Human Compared to a Non-intervention Diet and Caloric Restriction: A Meta-Analysis of Randomized Controlled Trials

Background

The popularity of applying intermittent fasting (IF) has increased as more and more people are trying to avoid or alleviate obesity and metabolic disease. This study aimed to systematically explore the effects of various IF in humans.

Methods

The randomized controlled trials (RCTs) related to IF vs. non-intervention diet or caloric restriction (CR) were retrieved in PubMed, Web of Science, Cochrane Library database, and Embase. Extraction outcomes included, but were not limited to, weight, body mass index (BMI), waist circumference (WC), fasting glucose, and triglyceride (TG).

Results

This study includes 43 RCTs with 2,483 participants. The intervention time was at least 1 month, and the median intervention time was 3 months. Contrasting results between IF and non-intervention diet showed that participants had lower weight (weighted mean difference (WMD) = 1.10, 95% CI: 0.09–2.12, p = 0.03) and BMI after IF (WMD = 0.38, 95% CI: 0.08–0.68, p = 0.01). The WC of participants after IF decreased significantly compared with the non-intervention diet (WMD = 1.02, 95% CI: 0.06–1.99, p = 0.04). IF regulated fat mass (FM) more effectively than non-intervention diet (WMD = 0.74, 95% CI: 0.17–1.31, p = 0.01). The fat-free mass of people after IF was higher (WMD = −0.73, 95% CI: (−1.45)–(−0.02), p = 0.05). There was no difference in fasting blood glucose concentrations between participants in the after IF and non-intervention diet groups. The results of insulin concentrations and HOMA-IR, though, indicated that IF was significantly more beneficial than non-intervention diet (standard mean difference (SMD) = −0.21, 95% CI: 0.02–0.40, p = 0.03, and WMD = 0.35, 95% CI: 0.04–0.65, p = 0.03, respectively). Cholesterol and TG concentrations in participants after IF were also lower than that after a nonintervention diet (SMD = 0.22, 95% CI: 0.09–0.35, p = 0.001 and SMD = 0.13, 95% CI: 0.00–0.26, p = 0.05, respectively). IF outcomes did not differ from CR except for reduced WC.

Conclusion

Intermittent fasting was more beneficial in reducing body weight, WC, and FM without affecting lean mass compared to the non-intervention diet. IF also effectively improved insulin resistance and blood lipid conditions compared with non-intervention diets. However, IF showed less benefit over CR.

Time-Restricted Feeding Improved Vascular Endothelial Function in a High-Fat Diet-Induced Obesity Rat Model

Obesity, where there is enhancement of stored body fat in adipose tissues, is associated with cardiovascular complications that are mainly related to atherosclerosis. Time-restricted feeding (TRF) is a form of restricted eating aimed at reducing weight in obese subjects. The present study aims to investigate changes in vascular endothelial function, endothelial nitric oxide synthase (eNOS), and protein kinase B (Akt) protein expressions with TRF in obese and normal rats. Male Sprague Dawley rats were divided into two normal and three obese groups; obesity was induced in the obese groups by feeding with a high-fat diet (HFD) for six weeks. After six weeks, rats were equally divided into five groups (n = 7 per group): Normal group (NR) which continued on a standard diet for six more weeks, normal group switched to TRF with a standard diet for six weeks (NR + TRFSD), obese group (OR) which continued on HFD for six more weeks, obese group switched to TRF of HFD (OR + TRFHFD), and obese group switched to TRF of a standard diet (OR + TRFSD). TRF was practiced for six weeks, after which the rats were sacrificed. Aortic endothelium-dependent and endothelium-independent relaxations and contractions were assessed using the organ bath. Aortic eNOS and Akt protein expressions were determined using immunoblotting. Fasting blood glucose, body weight, body mass index (BMI), serum lipid profile, Lee’s index, serum insulin levels, and sensitivity (HOMA-IR) were also measured. Endothelium-dependent relaxation was significantly impaired, while endothelium-dependent contraction increased in obese rats compared to that in normal rats. Both obese groups which underwent TRF with a HFD and standard diet improved their impairments in endothelium-dependent relaxation and reduced endothelium-dependent contraction; these were associated with increased expressions of aortic eNOS and Akt protein. Both obese groups with TRF reduced body weight, BMI, Lee’s index, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and improved insulin sensitivity. TRF improved endothelium-dependent relaxation and reduced endothelium-dependent contraction, thus attenuating endothelial dysfunction in obese rats. These were associated with increased aortic eNOS and Akt protein expressions.

Calorie Restriction with or without Time-Restricted Eating in Weight Loss

BACKGROUND

The long-term efficacy and safety of time-restricted eating for weight loss are not clear.

METHODS

We randomly assigned 139 patients with obesity to time-restricted eating (eating only between 8:00 a.m. and 4:00 p.m.) with calorie restriction or daily calorie restriction alone. For 12 months, all the participants were instructed to follow a calorie-restricted diet that consisted of 1500 to 1800 kcal per day for men and 1200 to 1500 kcal per day for women. The primary outcome was the difference between the two groups in the change from baseline in body weight; secondary outcomes included changes in waist circumference, body-mass index (BMI), amount of body fat, and measures of metabolic risk factors.

RESULTS

Of the total 139 participants who underwent randomization, 118 (84.9%) completed the 12-month follow-up visit. The mean weight loss from baseline at 12 months was -8.0 kg (95% confidence interval [CI], -9.6 to -6.4) in the time-restriction group and -6.3 kg (95% CI, -7.8 to -4.7) in the daily-calorie-restriction group. Changes in weight were not significantly different in the two groups at the 12-month assessment (net difference, -1.8 kg; 95% CI, -4.0 to 0.4; P = 0.11). Results of analyses of waist circumferences, BMI, body fat, body lean mass, blood pressure, and metabolic risk factors were consistent with the results of the primary outcome. In addition, there were no substantial differences between the groups in the numbers of adverse events.

CONCLUSIONS

Among patients with obesity, a regimen of time-restricted eating was not more beneficial with regard to reduction in body weight, body fat, or metabolic risk factors than daily calorie restriction. (Funded by the National Key Research and Development Project [No. 2018YFA0800404] and others; ClinicalTrials.gov number, NCT03745612.).

Assessing temporal eating pattern in free living humans through the myCircadianClock app

The quality and quantity of nutrition impact health. However, chrononutrition, the timing, and variation of food intake in relation to the daily sleep-wake cycle are also important contributors to health. This has necessitated an urgent need to measure, analyze, and optimize eating patterns to improve health and manage disease. While written food journals, questionnaires, and 24-hour dietary recalls are acceptable methods to assess the quantity and quality of energy consumption, they are insufficient to capture the timing and day-to-day variation of energy intake. Smartphone applications are novel methods for information-dense real-time food and beverage tracking. Despite the availability of thousands of commercial nutrient apps, they almost always ignore eating patterns, and the raw real-time data is not available to researchers for monitoring and intervening in eating patterns. Our lab developed a smartphone app called myCircadianClock (mCC) and associated software to enable long-term real-time logging that captures temporal components of eating patterns. The mCC app runs on iOS and android operating systems and can be used to track multiple cohorts in parallel studies. The logging burden is decreased by using a timestamped photo and annotation of the food/beverage being logged. Capturing temporal data of consumption in free-living individuals over weeks/months has provided new insights into diverse eating patterns in the real world. This review discusses (1) chrononutrition and the importance of understanding eating patterns, (2) the myCircadianClock app, (3) validation of the mCC app, (4) clinical trials to assess the timing of energy intake, and (5) strengths and limitations of the mCC app.

Time-restricted Eating for the Prevention and Management of Metabolic Diseases

Time-restricted feeding (TRF, animal-based studies) and time-restricted eating (TRE, humans) are an emerging behavioral intervention approach based on the understanding of the role of circadian rhythms in physiology and metabolism. In this approach, all calorie intake is restricted within a consistent interval of less than 12 hours without overtly attempting to reduce calories. This article will summarize the origin of TRF/TRE starting with concept of circadian rhythms and the role of chronic circadian rhythm disruption in increasing the risk for chronic metabolic diseases. Circadian rhythms are usually perceived as the sleep-wake cycle and dependent rhythms arising from the central nervous system. However, the recent discovery of circadian rhythms in peripheral organs and the plasticity of these rhythms in response to changes in nutrition availability raised the possibility that adopting a consistent daily short window of feeding can sustain robust circadian rhythm. Preclinical animal studies have demonstrated proof of concept and identified potential mechanisms driving TRF-related benefits. Pilot human intervention studies have reported promising results in reducing the risk for obesity, diabetes, and cardiovascular diseases. Epidemiological studies have indicated that maintaining a consistent long overnight fast, which is similar to TRE, can significantly reduce risks for chronic diseases. Despite these early successes, more clinical and mechanistic studies are needed to implement TRE alone or as adjuvant lifestyle intervention for the prevention and management of chronic metabolic diseases.

Current Evidence and Directions for Intermittent Fasting During Cancer Chemotherapy

Almost 40% of the adult population in the USA will be diagnosed with cancer in their lifetime. Diet is a modifiable factor which is known to affect cancer risk and recurrence. Yet, little is known about how diet influences cancer treatment outcomes. Intermittent fasting, characterized by periods of abstaining from foods and beverages alternated with periods of ad libitum intake, when adopted in the context of chemotherapy, has shown promise in preclinical models resulting in decreased vomiting, diarrhea, visible discomfort, and improved insulin sensitivity and efficacy of chemotherapeutic treatment. Although intermittent fasting during receipt of chemotherapy has been well-established in preclinical models, limited numbers of human studies are now being reported. This review aims to survey the current data examining the effect of intermittent fasting on chemotherapy efficacy, patient treatment outcomes, patient centered outcomes, and circulating biomarkers associated with cancer. Available data show that periodic fasting, a form of intermittent fasting, may hold potential to improve the effectiveness of chemotherapy, decrease treatment-related side effects and cancer-promoting factors such as insulin, while ameliorating treatment-related decreases in quality of life and daily functioning. Larger controlled periodic fasting trials, including exploration of alternate forms of intermittent fasting, are needed to better elucidate the effect of intermittent fasting on treatment and patient outcomes during chemotherapy.

Temporal Eating Patterns and Eating Windows among Adults with Overweight or Obesity

We aim to describe temporal eating patterns in a population of adults with overweight or obesity. In this cross-sectional analysis, data were combined from two separate pilot studies during which participants entered the timing of all eating occasions (>0 kcals) for 10-14 days. Data were aggregated to determine total eating occasions, local time of the first and last eating occasions, eating window, eating midpoint, and within-person variability of eating patterns. Eating patterns were compared between sexes, as well as between weekday and weekends. Participants (n = 85) had a median age of 56 ± 19 years, were mostly female (>70%), white (56.5%), and had a BMI of 31.8 ± 8.0 kg/m². The median eating window was 14 h 04 min [12 h 57 min-15 h 21 min], which was significantly shorter on the weekend compared to weekdays (p < 0.0001). Only 13.1% of participants had an eating window <12 h/d. Additionally, there was greater irregularity with the first eating occasion during the week when compared to the weekend (p = 0.0002). In conclusion, adults with overweight or obesity have prolonged eating windows (>14 h/d). Future trials should examine the contribution of a prolonged eating window on adiposity independent of energy intake.

Effect of Epidemic Intermittent Fasting on Cardiometabolic Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Intermittent fasting (IF) has gained attention as a promising diet for weight loss and dysmetabolic diseases management. This systematic review aimed to investigate the effects of IF on cardiometabolic risk factors (CMRFs). A systematic literature search was carried out using three electronic databases, namely PubMed, Embase, and the Cochrane Library, until October 2020. Randomized controlled trials that compared the IF intervention with a control group diet were included. Fourteen effect sizes were expressed as weighted mean difference (WMD) using a fixed-effects model and 95% confidence intervals (CI). Compared to the ones within control groups, participants exposed to the IF intervention reduced their body weight (WMD, −1.78 kg; 95% CI, −2.21 to −1.35; p <0.05), waist circumference (WMD, −1.19 cm; 95% CI, −1.8 to −0.57; p <0.05), fat mass (WMD, −1.26 kg; 95% CI, −1.57 to −0.95; p <0.05), body mass index (WMD, −0.58 kg/m²; 95% CI, −0.8 to −0.37; p <0.05), systolic blood pressure (WMD, −2.14 mmHg; 95% CI: −3.54 to −0.73; p <0.05), diastolic blood pressure (WMD: −1.38 mmHg, 95% CI, −2.35 to −0.41, p <0.05), fasting blood glucose (WMD: −0.053 mmol/L; 95% CI: −0.105 to 0.001; p <0.05), fasting insulin (WMD, −0.8 mIU/L; 95% CI, −1.15 to −0.44; p <0.05), insulin resistance (WMD, −0.21; 95% CI, −0.36 to −0.05; p <0.05), total cholesterol (WMD, −0.10 mmol/L; 95% CI, −0.17 to −0.02; p <0.05), and triglycerides (WMD, −0.09 mmol/L; 95% CI, −0.13 to −0.04; p <0.05). No effects were observed for low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or glycosylated hemoglobin. This meta-analysis supports the role of IF in improving the component composition of CMRFs, including weight, waist circumference, fat mass, BMI, blood pressure, total cholesterol, triglycerides, fasting insulin, and insulin resistance, compared to a control group diet. Further research on IF interventions should take into account long-term and well-designed administration to draw definitive conclusions.

Missing puzzle pieces of time-restricted-eating (TRE) as a long-term weight-loss strategy in overweight and obese people? A systematic review and meta-analysis of randomized controlled trials

The efficacy of using time restricted eating (TRE) for weight management and to mitigate metabolic disorders in overweight and obese people remains debatable. This meta-analysis quantified the impact of TRE on weight loss and metabolic health in overweight and obese people. The pooled results were subjected to a random-effects modeling using Hartung-Knapp-Sidik-Jonkman (HKSJ) method. Additionally, subgroup analysis was conducted based on study types, randomized controlled trials (RCTs) vs. non-randomized studies of interventions (NRSIs). Pooled results showed that subjects on TRE regimen (> 4 weeks) achieved a significant weight loss in comparison with unrestricted time regimen (weighted mean difference: -2.32%; 95% CI: -3.50, -1.14%; p < 0.01); however, weight loss was mainly attributed to the loss of lean mass rather than fat mass. The magnitude of weight loss was inversely correlated with daily fasting duration in RCTs. TRE significantly decreased the diastolic blood pressure and fasting insulin. An increase of low-density lipoprotein cholesterol (LDL-C) was observed in the TRE group. Favorable effect of TRE was observed on glucose metabolism but not on lipid profiles independent of weight loss. Hence TRE shall be administered with caution to overweight and obese people who have comorbidities such as dyslipidemia and sarcopenia.

Effect of High-Intensity Interval Training and Intermittent Fasting on Body Composition and Physical Performance in Active Women

Nutritional strategies may have an effect on body composition and physical performance. Intermittent fasting (IF) is an eating pattern that cycles between periods of eating and fasting in specified time periods. Moreover, it is a common strategy among members of the athlete population that are looking for weight loss. However, this strategy may negatively affect physical performance, as compared to other weight loss strategies. The main purpose of this research was to use a cross-over design to study the effects of HIIT, with or without intermittent fasting, on muscular and anaerobic performance in 14 active women (27 ± 6 y). To assess performance, body composition (anthropometry), hand-grip strength, and counter-movement jump (CMJ) height was measured, and a 30 s Wingate test was completed assessed. HIIT + IF reduced fat mass (1 kg, p < 0.05, d = 1.1; 1.5%, p < 0.01, d = 1.0) and increased CMJ height (6.2 cm, p < 0.001, d = 1.8). In addition, the change in CMJ height in HIIT + IF was higher over HIIT (5.2 cm, p < 0.001, d = 1.9). In conclusion, intermittent fasting could be a nutritional strategy to decrease fat mass and increase jumping performance. However, longer duration programs would be necessary to determine whether other parameters of muscle performance could be positively affected by IF.