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

Adverse events profile associated with intermittent fasting in adults with overweight or obesity: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

There is little evidence to comprehensively summarize the adverse events (AEs) profile of intermittent fasting (IF) despite its widespread use in patients with overweight or obesity.

METHODS

We searched the main electronic databases and registry websites to identify eligible randomized controlled trials (RCTs) comparing IF versus control groups. A direct meta-analysis using a fixed-effect model was conducted to pool the risk differences regarding common AEs and dropouts. Study quality was assessed by using the Jadad scale. Pre-specified subgroup and sensitivity analyses were conducted to explore potential heterogeneity.

RESULTS

A total of 15 RCTs involving 1,365 adult individuals were included. Findings did not show a significant difference between IF and Control in risk rate of fatigue [0%, 95% confidence interval (CI), -1% to 2%; P = 0.61], headache [0%, 95%CI: -1% to 2%; P = 0.86] and dropout [1%, 95%CI: -2% to 4%; P = 0.51]. However, a numerically higher risk of dizziness was noted among the IF alone subgroup with non-early time restricted eating [3%, 95%CI: -0% to 6%; P = 0.08].

CONCLUSIONS

This meta-analysis suggested that IF was not associated with a greater risk of AEs in adult patients affected by overweight or obesity. Additional large-scale RCTs stratified by key confounders and designed to evaluate the long-term effects of various IF regimens are needed to ascertain these AEs profile.

Effect of Isocaloric, Time-Restricted Eating on Body Weight in Adults With Obesity : A Randomized Controlled Trial

BACKGROUND

Time-restricted eating (TRE) lowers body weight in many studies. Whether TRE induces weight loss independent of reductions in calorie intake, as seen in rodent studies, is unknown.

OBJECTIVE

To determine the effect of TRE versus a usual eating pattern (UEP) on body weight in the setting of stable caloric intake.

DESIGN

Randomized, isocaloric feeding study. (ClinicalTrials.gov: NCT03527368).

SETTING

Clinical research unit.

PARTICIPANTS

Adults with obesity and prediabetes or diet-controlled diabetes.

INTERVENTION

Participants were randomly assigned 1:1 to TRE (10-hour eating window, 80% of calories before 1 p.m.) or UEP (≤16-hour window, ≥50% of calories after 5 p.m.) for 12 weeks. Both groups had the same nutrient content and were isocaloric with total calories determined at baseline.

MEASUREMENTS

Primary outcome was change in body weight at 12 weeks. Secondary outcomes were fasting glucose, homeostatic model assessment for insulin resistance (HOMA-IR), glucose area under the curve by oral glucose tolerance test, and glycated albumin. We used linear mixed models to evaluate the effect of interventions on outcomes.

RESULTS

All 41 randomly assigned participants (mean age, 59 years; 93% women; 93% Black race; mean BMI, 36 kg/m2) completed the intervention. Baseline weight was 95.6 kg (95% CI, 89.6 to 101.6 kg) in the TRE group and 103.7 kg (CI, 95.3 to 112.0 kg) in the UEP group. At 12 weeks, weight decreased by 2.3 kg (CI, 1.0 to 3.5 kg) in the TRE group and by 2.6 kg (CI, 1.5 to 3.7 kg) in the UEP group (average difference TRE vs. UEP, 0.3 kg [CI, -1.2 to 1.9 kg]). Change in glycemic measures did not differ between groups.

LIMITATION

Small, single-site study; baseline differences in weight by group.

CONCLUSION

In the setting of isocaloric eating, TRE did not decrease weight or improve glucose homeostasis relative to a UEP, suggesting that any effects of TRE on weight in prior studies may be due to reductions in caloric intake.

PRIMARY FUNDING SOURCE

American Heart Association.

Nutrient-epigenome interactions: Implications for personalized nutrition against aging-associated diseases

Aging is a multifaceted process involving genetic and environmental interactions often resulting in epigenetic changes, potentially leading to aging-related diseases. Various strategies, like dietary interventions and calorie restrictions, have been employed to modify these epigenetic landscapes. A burgeoning field of interest focuses on the role of microbiota in human health, emphasizing system biology and computational approaches. These methods help decipher the intricate interplay between diet and gut microbiota, facilitating the creation of personalized nutrition strategies. In this review, we analysed the mechanisms related to nutritional interventions while highlighting the influence of dietary strategies, like calorie restriction and intermittent fasting, on microbial composition and function. We explore how gut microbiota affects the efficacy of interventions using tools like multi-omics data integration, network analysis, and machine learning. These tools enable us to pinpoint critical regulatory elements and generate individualized models for dietary responses. Lastly, we emphasize the need for a deeper comprehension of nutrient-epigenome interactions and the potential of personalized nutrition informed by individual genetic and epigenetic profiles. As knowledge and technology advance, dietary epigenetics stands on the cusp of reshaping our strategy against aging and related diseases.

Time-restricted feeding can increase food-related impulsivity: a randomized controlled trial

OBJECTIVES

Although an increasing number of studies show that time-restricted feeding may improve metabolic health, studies examining the behavioral effects of this eating pattern are limited. This study examined the effect of time-restricted feeding on impulsivity in adults.

METHODS

Thirty adults aged 25-41 years participated in this randomized controlled trial. The intervention group followed time-restricted feeding for 4 weeks and there was no energy restriction in the intervention group (n = 15) or control group (n = 15). Impulsivity was assessed before and after the intervention with the Barratt Impulsiveness Scale and the Go/NoGo task.

RESULTS

The compliance rate (the percentage of days when participants had a feeding time of ≤ 8 hours/day) of the intervention group to the time-restricted feeding pattern was 92.38 ± 4.24%. The Barratt Impulsiveness Scale-11 total score of the intervention group increased from 55.53 ± 6.37 to 59.47 ± 7.67 (p = 0.02). During the Go/NoGo task, an indicator of inhibitory control, the reaction time to food and non-food stimuli was significantly shortened in the intervention group (respectively; p = 0.009, p = 0.01). In the control group, no significant change was detected in impulsivity determined by the BIS-11 or Go/NoGo task.

DISCUSSION

This study showed that although time-restricted feeding may reduce body weight, it can lead to increased impulsivity and impaired inhibitory control.Trial registration: ClinicalTrials.gov identifier: NCT04960969.

Chrononutrition in the Prevention and Management of Metabolic Disorders: A Literature Review

BACKGROUND

The concept of time-restricted eating (TRE) or time-restricted feeding (TRF) promotes daily periods of feeding and fasting to determine whole-body physiology. Chronic misalignment of circadian rhythms or chrono-disruption is related to an increased risk of diverse metabolic disorders. The progression of non-communicable diseases seems to be affected by the timing of meals. As a result, intermittent fasting is a promising approach for their management. The aim of the present literature review is to examine and scrutinize the TRE protocols in the fields of prevention and management of metabolic disorders.

METHODS

This is a thorough literature review of the reported associations among circadian rhythm, metabolic disorders, diabetes mellitus, obesity, TRE, TRF, dietary habits, circadian disruption, cardiovascular diseases, atherosclerosis, and non-alcoholic fatty liver to find the already existing clinical studies from the last decade (2014-2024) in the most precise scientific online databases, using relevant specific keywords. Several inclusion and exclusion criteria were applied to scrutinize only longitudinal, cross-sectional, descriptive, and prospective clinical human studies.

RESULTS

The currently available clinical findings remain scarce and suggest that chrononutrition behaviors such as TRE or TRF may promote several metabolic benefits, mainly in body weight control and fat loss. Improvements in glucose levels and lipid profiles are currently quite controversial since some clinical studies show little or no effect. As far as liver diseases are concerned, the efficacy of intermittent fasting seems to be stronger in the management of non-alcoholic fatty liver disease due to body weight decline and fat loss.

CONCLUSIONS

Even if there has been a gradual increase in clinical studies in the last few years, providing promising perspectives, currently, there is no conclusive evidence for the role of chrononutrition in metabolic disorders. Future studies should be well-designed with longer duration and larger sample sizes. Moreover, it is important to examine the best timing of the eating window and its feasibility.

Effectiveness of Time-Restricted Eating with Caloric Restriction vs. Caloric Restriction for Weight Loss and Health: Meta-Analysis

Time-restricted eating (TRE) is an increasingly popular dietary strategy for weight loss. Recent studies suggest that combining TRE with caloric restriction (CR) may have more favorable effects on both physical and biochemical aspects when compared with CR alone. Therefore, we performed a meta-analysis to compare the effects of TRE with CR vs. CR alone on anthropometric and biochemical measures in overweight or obese adults. We reviewed articles from PubMed, Web of science, EMBASE, and the Cochrane Library published before 25 May 2023. The meta-analysis incorporated data from seven randomized controlled trials of nine interventions, with a total of 231 participants in the TRE with CR group and 227 participants in the CR-only group. Data were analyzed using RewMan version 5.4.1. All results in our meta-analysis were described as mean difference (MD) with 95% confidence interval (Cl). Results showed that TRE with CR compared to CR alone resulted in significantly greater reductions in body weight (MD: -2.11 kg, 95% CI: -2.68 kg to -1.54 kg, p = < 0.00001, I2 = 42%), body fat mass (MD: -0.75 kg, 95% CI: -1.35 kg to -0.16 kg, p = 0.01; I2 = 0%), and waist circumference (MD: -1.27 cm, 95% CI: -2.36 cm to -0.19 cm, p = 0.02, I2 = 0%), while no additional impact of TRE in combination with CR in comparison to CR on serum biochemical parameters were found. Our results suggest that the improvement in biochemical parameters are mainly caused by CR, while improvements in anthropometric parameters are further enhanced by TRE.