Days Of Caloric Restriction Research Articles

Time-Restricted Eating Versus Daily Calorie Restriction: Effect on Sleep in Adults with Obesity over 12 Months.

Objective: The aim of this secondary analysis was to compare the effects of time-restricted eating (TRE) versus daily calorie restriction (CR) on sleep quality, duration, insomnia severity, and risk of obstructive sleep apnea in adults with obesity over one year. Methods: A total of 90 participants were randomized to one of three groups for 12 months: 8 h TRE (eating only between 12 p.m. and 8 p.m.); CR (25% daily calorie restriction) or a no-intervention control group. Results: By the end of the study, weight loss was 4.61 kg (95% CI; 7.37 to 1.85 kg; p ≤ 0.01) for the TRE group and 5.42 kg (CI; 9.13 to 1.71 kg; p ≤ 0.01) for the CR group, with no statistically significant difference between TRE and CR (0.81 kg [CI; 3.07 to 4.69]; p = 0.68]). Self-reported sleep quality, sleep duration, insomnia severity, and risk of obstructive sleep apnea did not change in the TRE or CR groups versus controls by month 12. Conclusions: These findings suggest that the weight loss produced by TRE and CR does not have any impact on various sleep parameters in adults with obesity over one year.

Lead-in calorie restriction enhances the weight-lowering efficacy of incretin hormone-based pharmacotherapies in mice

ObjectivesThe potential benefits of combining lifestyle changes with weight loss pharmacotherapies for obesity treatment are underexplored. Building on recent clinical observations, this study aimed to determine whether “lead-in” calorie restriction before administering clinically approved weight loss medications enhances the maximum achievable weight loss in preclinical models. MethodsDiet-induced obese mice (DIO) were exposed to 7 or 14 days of calorie restriction before initiating treatment with semaglutide (a glucagon-like peptide-1 receptor (GLP-1R) agonist), tirzepatide (a GLP-1R/glucose insulinotropic peptide receptor (GIPR) co-agonist), or setmelanotide (a melanocortin-4 receptor (MC4R) agonist). Follow-up assessments using indirect calorimetry determined the contributions of energy intake and expenditure linked to consecutive exposure to dieting followed by pharmacotherapy. ResultsCalorie restriction prior to treatment with semaglutide or tirzepatide enhanced the weight loss magnitude of both incretin-based therapies in DIO mice, reflected by a reduction in fat mass and linked to reduced energy intake and a less pronounced adaptive drop in energy expenditure. These benefits were not observed with the MC4R agonist, setmelanotide. ConclusionsOur findings provide compelling evidence that calorie restriction prior to incretin-based therapy enhances the achievable extent of weight loss, as reflected in a weight loss plateau at a lower level compared to that of treatment without prior calorie reduction. This work suggests that more intensive lifestyle interventions should be considered prior to pharmacological treatment, encouraging further exploration and discussion of the current standard of care.

Effect of 5:2 intermittent fasting diet versus daily calorie restriction eating on metabolic-associated fatty liver disease-a randomized controlled trial.

Both 5:2 IF diet (intermittent fasting) and daily caloric restriction eating had been suggested for management of MAFLD (Metabolic-Associated Fatty Liver Disease), this study aimed to evaluate the effects of 5:2 IF diet on body weight and metabolic parameters in adults with MAFLD, in comparison to daily caloric restriction eating. This single-center, double-blind, prospective, randomized controlled trial included 60 patients with MAFLD, who were administered either a 5:2 IF diet limited calories consumed for 2 days each week with no restrictions on the remaining 5 (Group 5:2 IF diet) or a daily calorie restriction eating (Group daily calorie restriction). Fibrotouch-B instrument assessment, ultrasound assessment of hepatic steatosis, anthropometric indices and body composition analysis, blood sample measurements were conducted during two distinct visits: initially on the day of study commencement (T1), and subsequently at the conclusion of the 12-week intervention period (T2). In comparison to daily calorie restriction eating, the 5:2 IF diet significantly decreased the proportion of hepatic steatosis ≥moderate (29.6% vs. 59.3%, p = 0.028) and the degree of hepatic fibrosis F ≥ 2 (3.7% vs. 25.9%, p = 0.05), and fewer percentage of patients were diagnosed with fatty liver via upper abdominal ultrasound in the 5:2 intermittent fasting diet group (33.3% vs. 63.0%, p = 0.029). Additionally, the CAP (controlled attenuation parameter) and LSM (liver stiffness measurements) value were significantly lower in the 5:2 IF diet group (p < 0.05). No statistically significant differences were observed between the two groups in terms of weight, BMI (body mass index), WC (waist circumference), HC (hip circumference), and WHR (waist to hip ratio). Similarly, there were no significant differences in lipid profile, glycemic indices and adverse events (p > 0.05). In summary, although both 5:2 IF diet and daily caloric restriction eating achieved similar effect on body weight, liver enzymes, lipid profile and glycemic indices after 12 weeks treatment, 5:2 IF diet demonstrates better improvement in fibrosis and steatosis scores independently from weight regulation. Consequently, it is anticipated to emerge as a viable dietary modality for lifestyle intervention among patients diagnosed with MAFLD. https://www.crd.york.ac.uk/PROSPERO, identifier ChiCTR2400080292.

The effects of time-restricted eating alone or in combination with probiotic supplementation in comparison with a calorie-restricted diet on endocrine and metabolic profiles in women with polycystic ovary syndrome: A randomized clinical trial.

To assess the impact of intermittent fasting, with or without probiotic supplementation, versus a calorie-restricted diet on anthropometric measures, metabolic status and gonadal variables in women with polycystic ovary syndrome (PCOS). This is a randomized, placebo-controlled, parallel-arm clinical trial. The effects of the 14:10 early time-restricted eating (eTRE) strategy alone or combined with probiotics, on obese women with PCOS, were investigated. Participants were divided into three groups: eTRE plus probiotics (n = 30), eTRE plus placebo (n = 30) and a control group following a standard three-meal-per-day diet with daily calorie restriction (DCR) (n = 30). Over 8 weeks, various anthropometric, metabolic, menstrual and gonadal variables were assessed. A total of 90 individuals were included in the study, with a mean body weight of 81.4 kg, and a mean age of 30 years. Mean (standard deviation) weight loss was not different between the groups at week 8 (TRE + probiotic: -2.2 [1.6] kg vs. TRE + placebo: -2.9 [2.7] kg vs. DCR: -2.5 [1.7] kg). Results revealed that, while all three regimes led to reductions in body weight, body mass index, vascular risk indicators, hirsutism and acne scores, there were no statistically significant differences between the eTRE groups and the control group in terms of weight loss, or improvements in metabolic, menstrual and gonadal variables (P > .05). Additionally, combining probiotics with eTRE did not benefit hormonal and cardiometabolic factors (P > .05). The eTRE alone or eTRE plus probiotics did not result in significantly greater weight loss or improvements in metabolic, menstrual and gonadal variables compared with the standard three-meal DCR diet.

Effect of 8-Hour Time-Restricted Eating Versus Daily Calorie Restriction on Sleep in Adults With Type 2 Diabetes

Effect of 8-Hour Time-Restricted Eating Versus Daily Calorie Restriction on Sleep in Adults With Type 2 Diabetes

Obesity Genetic Risk Scores and Weight Loss in Participants From the Daily Caloric Restriction Versus Intermittent Fasting Trial (DRIFT)

Obesity Genetic Risk Scores and Weight Loss in Participants From the Daily Caloric Restriction Versus Intermittent Fasting Trial (DRIFT)

Effect of time restricted eating versus daily calorie restriction on sex hormones in males and females with obesity.

This study examined the effects of time restricted eating (TRE) on sex hormones in males and females, versus daily calorie restriction (CR). Adults with obesity (n = 90) were randomized to 1 of 3 groups for 12-months: 8-h TRE (eating only between 12:00 to 8:00 pm, with no calorie counting); CR (25% energy restriction daily); or control. Body weight decreased (P < 0.01) in the TRE and CR groups, relative to controls, in males, premenopausal females, and postmenopausal females, by month 12. Total testosterone, dehydroepiandrosterone (DHEA), and sex hormone binding globulin (SHBG) levels did not change over time, or between groups, in males, premenopausal females, and postmenopausal females. Estradiol, estrone, and progesterone were only measured in postmenopausal females, and remained unchanged. These findings suggest that TRE produces significant weight loss but does not impact circulating sex hormone levels in males and females with obesity over 12 months, relative to CR and controls.

Does an alternate-day modified fasting diet improve premenstrual syndrome symptoms and health-related quality of life in obese or overweight women with premenstrual syndrome? A randomized, controlled trial.

Premenstrual syndrome disorder (PMS) is a condition that affects health-related quality of life (HRQoL) and encompasses a variety of symptoms, including psychological, physical, and behavioral symptoms. Some evidence suggests that an increase in body mass index (BMI) can reduce both HRQoL and menstrual quality. This is because the body fat tissue can affect menstrual cycles by changing the estrogen/progesterone ratio. This study investigated the impact of two diets alternate-day modified fasting (ADMF) and daily calorie restriction (DCR) - on PMS syndrome and HRQoL. The study was a randomized controlled, open-label trial that lasted for 8 weeks and involved 60 obese/overweight women. Participants were recruited from the Health Service Centers of Kashan University of Medical Sciences using simple random sampling. The study compared the impact of the ADMF and DCR diets on HRQoL and PMS symptoms. Patients were classified based on their BMI and age and then allocated to either the intervention (ADMF) or control (DCR) group using a random numbers table. The study measured HRQoL, PMS severity, weight, BMI, body fat mass, waist circumference, fat-free mass, and skeletal muscle mass before and after the study. The study had an almost 18% dropout rate. Significant improvements were observed in mood lability (p = 0.044) and expressed anger (p < 0.001) in relation to PMS symptoms. However, no significant differences were detected in the changes of other COPE subscales. The ADMF diet had a significant impact on the 12-item Short-Form Health Survey (SF-12) total score (p < 0.001) and physical function subscales (p = 0.006) as well as mental health (p < 0.001) when compared to the control diet. This implies that the ADMF diet increased both SF-12 total score and its subscales. The intervention led to improvements in HRQoL, physical function, and mental health. Additionally, significant improvements in BMI and weight were observed between the two groups pre- and post-study (p < 0.001). Anthropometric data, including body fat mass and waist circumference, showed a significant improvement (p < 0.001 and p = 0.029, respectively) before and after the study. However, there were no significant changes in fat-free mass (p = 0.936) and skeletal muscle mass (p = 0.841) between the two groups. The study suggested that ADMF can improve HRQoL, mood lability, and expressed anger. It also showed that ADMF can reduce waist circumference, weight, and body fat mass in obese/overweight women. The Iranian Registry of Clinical Trials (IRCT20220522054958N1).

Effect of Time-Restricted Eating versus Daily Calorie Restriction on Mood and Quality of Life in Adults with Obesity.

The purpose of this secondary analysis is to compare the effects of two popular weight loss regimens, time-restricted eating (TRE) and daily calorie restriction (CR), on mood and quality-of-life measures in adults with obesity. Ninety participants were randomized to one of three interventions for 12 months: 8 h TRE (eating only between 12:00 and 8:00 p.m., with no calorie counting); CR (25% energy restriction daily); or no-intervention control group. Questionnaires were administered to measure mood (Beck Depression Inventory-II (BDI-II), and Profile of Mood States (POMS)) and quality of life (Rand 36-Item Short Form) at baseline and month 12. Body weight decreased in the TRE group (-4.87%, 95%CI: -7.61, -2.13) and CR group (-5.30%, 95%CI: -9.06, -1.54) versus controls, with no difference between TRE and CR. The BDI-II depression score did not change in the TRE or CR group, versus controls, by month 12. Likewise, there were no changes in any of the POMS subscales (tension, depression, anger, fatigue, anger, confusion, or vigor) or the total mood disturbance score in the TRE or CR group versus controls. As for quality of life, there were no significant changes in the SF-36 constructs of mental health, bodily pain, and general physical health in the TRE or CR group versus controls. However, there was a trend towards increased vitality in the TRE group (7.77 [95% CI: 0.15, 15.39] p = 0.05) relative to controls. There were no associations between changes in body weight, physical activity, mood, and quality of life in any group by the end of the study. These findings suggest that TRE and CR produce similar degrees of weight loss, but impact neither mood nor quality of life in adults with obesity over 12 months. Future well-powered studies will be needed to confirm these findings.

Intermittent fasting for the prevention of cardiovascular disease: implications for clinical practice.

Cardiovascular disease remains one of the most prevalent and preventable chronic conditions worldwide. Nutrition plays an important role in reducing several risk factors associated with cardiovascular disease. Intermittent fasting has been rapidly gaining interest among patients with cardiometabolic disease as a nutritional strategy for improving cardiovascular outcomes. However, research had yet to determine whether intermittent fasting provides greater cardiometabolic benefits compared to continuous daily caloric restriction. A recent Cochrane review has synthesised the benefits of intermittent fasting for the prevention of cardiovascular disease but is limited by its interpretation of the findings for clinical practice. This commentary aims to critically appraise the methods used within the review by Allaf et al, 2021 and expand upon the findings to determine its implications for clinical practice.

The effects of early time restricted eating plus daily caloric restriction compared to daily caloric restriction alone on continuous glucose levels.

The median eating duration in the U.S. is 14.75h, spread throughout the period of wakefulness and ending before sleep. Food intake at an inappropriate circadian time may lead to adverse metabolic outcomes. Emerging literature suggests that time restricted eating (TRE) may improve glucose tolerance and insulin sensitivity. The aim was to compare 24-h glucose profiles and insulin sensitivity in participants after completing 12weeks of a behavioral weight loss intervention based on early TRE plus daily caloric restriction (E-TRE+DCR) or DCR alone. Eighty-one adults with overweight or obesity (age 18-50years, BMI 25-45kg/m2) were randomized to either E-TRE+DCR or DCR alone. Each participant wore a continuous glucose monitor (CGM) for 7days and insulin sensitivity was estimated using the homeostatic model assessment of insulin resistance (HOMA-IR) at Baseline and Week 12. Changes in CGM-derived measures and HOMA-IR from Baseline to Week 12 were assessed within and between groups using random intercept mixed models. Forty-four participants had valid CGM data at both time points, while 38 had valid glucose, insulin, HOMA-IR, and hemoglobin A1c (A1c) data at both timepoints. There were no significant differences in sex, age, BMI, or the percentage of participants with prediabetes between the groups (28% female, age 39.2±6.9years, BMI 33.8±5.7kg/m2, 16% with prediabetes). After adjusting for weight, there were no between-group differences in changes in overall average sensor glucose, standard deviation of glucose levels, the coefficient of variation of glucose levels, daytime or nighttime average sensor glucose, fasting glucose, insulin, HOMA-IR, or A1c. However, mean amplitude of glycemic excursions changed differently over time between the two groups, with a greater reduction found in the DCR as compared to E-TRE+DCR (p=0.03). There were no major differences between E-TRE+DCR and DCR groups in continuous glucose profiles or insulin sensitivity 12weeks after the intervention. Because the study sample included participants with normal baseline mean glucose profiles and insulin sensitivity, the ability to detect changes in these outcomes may have been limited.

OR14-01-23 Effect of 8-Hour Time Restricted Eating Versus Daily Calorie Restriction on Body Weight and Glycemic Control in Adults With Type 2 Diabetes

OR14-01-23 Effect of 8-Hour Time Restricted Eating Versus Daily Calorie Restriction on Body Weight and Glycemic Control in Adults With Type 2 Diabetes

Targeting Energy Intake and Circadian Biology to Engage Mechanisms of Aging in Older Adults With Obesity: Calorie Restriction and Time-Restricted Eating.

With the rise in obesity across age groups, it has been a hindrance to engaging in physical activity and mobility in older adults. Daily calorie restriction (CR) up to 25% has been the cornerstone of obesity management even though the safety in older adults remains incompletely understood. Although some adults can follow CR with clinically significant weight loss and improved health metrics, CR faces 2 obstacles-many fail to adopt CR and even among those who can adopt it short term, long-term compliance can be difficult. Furthermore, there is a continuing debate about the net benefits of CR-induced weight loss in older adults because of the concern that CR may worsen sarcopenia, osteopenia, and frailty. The science of circadian rhythm and its plasticity toward the timing of nutrition offer promise to alleviate some challenges of CR. The new concept of Time-Restricted Feeding/Eating (TRF for animal studies and TRE for human studies) can be an actionable approach to sustaining the circadian regulation of physiology, metabolism, and behavior. TRE can often (not always) lead to CR. Hence, the combined effect of TRE through circadian optimization and CR can potentially reduce weight and improve cardiometabolic and functional health while lessening the detrimental effects of CR. However, the science and efficacy of TRE as a sustainable lifestyle in humans are in its infancy, whereas animal studies have offered many desirable outcomes and underlying mechanisms. In this article, we will discuss the scope and opportunities to combine CR, exercise, and TRE to improve functional capacity among older adults with obesity.

Alternate-day modified fasting diet improves weight loss, subjective sleep quality and daytime dysfunction in women with obesity or overweight: a randomized, controlled trial.

Both sleep time and quality can be associated with overweight or obesity. In obese people, visceral fat tissue develops, which results in an increment in the production of cytokines. The increased production of inflammatory cytokines can disturb the sleep/wake cycle. Therefore, weight loss by reducing fat tissue can improve sleep disorders. Intermittent fasting diets are popular and effective diets that can decrease body weight and improve anthropometric data and body composition. The present study aimed to evaluate the effect of Alternate-day Modified Fasting (ADMF) on sleep quality, body weight, and daytime sleepiness. Classification of 56 obese or overweight women, based on age and body mass index (BMI), was done using stratified randomization. Then individuals were assigned to the ADMF group (intervention) or Daily Calorie Restriction (CR) group (control) using the random numbers table for 8 weeks. We measured the Pittsburgh sleep quality Index (PSQI), weight, BMI, and the Epworth sleepiness scale (ESS) as primary outcomes and assessed subjective sleep quality (SSQ), sleep latency, sleep disturbances, habitual sleep efficiency, daytime dysfunction, and sleep duration as secondary outcomes at baseline and after the study. Following an ADMF diet resulted in a greater decrease in weight (kg) [-5.23 (1.73) vs. -3.15 (0.88); P < 0.001] and BMI (kg/m2) [-2.05 (0.66) vs. -1.17 (0.34); P < 0.001] compared to CR. No significant differences were found in the changes of PSQI [-0.39 (1.43) vs. -0.45 (1.88); P = 0.73] and ESS [-0.22 (1.24) vs. -0.54 (1.67); P = 0.43] between two groups. Also, following the ADMF diet led to significant changes in SSQ [-0.69 (0.47) vs. -0.08 (0.40); P = <0.001], and daytime dysfunction [-0.65 (0.57) vs. 0.04 (0.75); P: 0.001] in compare with CR diet. These results suggested that an ADMF could be a beneficial diet for controlling body weight and BMI. The ADMF diet didn't affect PSQI and ESS in women with overweight or obesity but significantly improved SSQ and daytime dysfunction. The Iranian Registry of Clinical Trials (IRCT20220522054958N3), https://www.irct.ir/trial/64510.

Physiological and behavioural effects of intermittent fasting vs daily caloric restriction in meat-type poultry

Intermittent fasting (IF) is the practice of temporal food restriction to promote metabolic switching between a glucose- and a ketone-based metabolism, which has been reported to come with diverse health benefits. IF practices appear to confer many of the advantages of caloric restriction without restricting total energy intake, and studies in both rodents and humans suggest organism-wide improvements in neurological, cardiovascular and metabolic health. IF is also commonly employed in the commercial rearing of breeding meat-type poultry, i.e. broiler breeders, which require strict feed restriction throughout life to maintain physical health. While the scientific poultry literature holds vast amounts of data on such “skip-a-day” feeding schedules, it has been unclear to what extent avian and mammalian literature may be compared as broiler breeders are typically feed-restricted to around 30% of ad libitum intake even in IF schedules. In this study, we set out to disentangle the effects of IF and caloric restriction in meat-type poultry by employing both IF and daily feeding schedules at two different restriction levels. Our results suggest that the physiological response to IF in chickens is only marginally affected by the intensity of feed restriction, while behavioural parameters are more closely related to feeding level and are expected to better mirror animal welfare. Our results suggest that avian and mammalian literature on IF should be comparable. Meat-type chickens do show some peculiarities in response to IF, such as a reduced insulin sensitivity, but it is currently unclear whether this is true for all chickens or is an effect of the intense selection for rapid growth in meat-type chickens.

Effect of modified alternate day fasting diet on the severity of premenstrual syndrome and health-related quality of life in women with overweight or obesity: a trial study protocol

IntroductionPremenstrual syndrome (PMS) includes a range of physical, behavioural and psychological symptoms and decreases women’s health-related quality of life (HRQoL). It has been proposed that increased body mass index (BMI)...

Effects of Time-Restricted Eating on Nonalcoholic Fatty Liver Disease

The efficacy and safety of time-restricted eating (TRE) on nonalcoholic fatty liver disease (NAFLD) remain uncertain. 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. 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. 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. 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. 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. 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. ClinicalTrials.gov Identifiers: NCT03786523 and NCT04988230.

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.

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

Comparison of the effect of modified intermittent fasting and daily calorie restriction on sleep quality, anthropometric data, and body composition in women with obesity or overweight: study protocol of a randomized controlled trial

BackgroundSleep disturbances are common in nearly one-third of adults. Both low quality of sleep and sleep time could be related to increased obesity. An increase in visceral adipose tissue can result in the secretion of inflammatory cytokines. Inflammatory cytokines can lead to a disturbance of the sleep-wake rhythm. Therefore, weight loss may improve sleep quality and duration. Intermittent fasting diet as a popular diet reduces body weight and improves anthropometric indices. This study is performed to further investigate the effect of a modified intermittent fasting diet on sleep quality and anthropometric indices.MethodsThis is an open-label randomized controlled trial to evaluate the effect of daily calorie restriction (control) and modified intermittent fasting (intervention) on sleep quality, anthropometric data, and body composition in women with obesity or overweight for 8 weeks. Fifty-six participants will be classified using stratified randomization based on body mass index (BMI) and age. Then, participants will be assigned to one of the two groups of intervention or control using the random numbers table. The sleep quality, daytime sleepiness, and insomnia will be evaluated by using the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Insomnia Severity Index respectively. The primary outcomes chosen for the study were as follows: the difference in sleep quality, daytime sleepiness, insomnia, BMI, fat-free mass (FFM), body fat mass, waist circumference, and waist-to-hip ratio from baseline to 8 weeks. Secondary outcomes chosen for the study were as follows: the difference in hip circumference, the visceral fat area, percent body fat, soft lean mass, skeletal muscle mass, extracellular water ratio, and total body water from baseline to 8 weeks.DiscussionThis study will investigate the effect of intermittent fasting intervention compared with daily calorie restriction on sleep quality and anthropometric indices. The information gained will enhance our understanding of fasting interventions, which can be used to improve clinical dietary recommendations. The findings will help to disclose as yet the unknown relationship between diet and sleep quality.Trial registrationIranian Registry of Clinical Trials IRCT20220522054958N3. Registered on 8 July 2022. https://www.irct.ir/trial/64510.

Does Timing Matter? A Narrative Review of Intermittent Fasting Variants and Their Effects on Bodyweight and Body Composition

The practice of fasting recently has been purported to have clinical benefits, particularly as an intervention against obesity and its related pathologies. Although a number of different temporal dietary restriction strategies have been employed in practice, they are generally classified under the umbrella term "intermittent fasting" (IF). IF can be stratified into two main categories: (1) intra-weekly fasting (alternate-day fasting/ADF, twice-weekly fasting/TWF) and (2) intra-daily fasting (early time-restricted eating/eTRE and delayed time-restricted eating/dTRE). A growing body of evidence indicates that IF is a viable alternative to daily caloric restriction (DCR), showing effectiveness as a weight loss intervention. This paper narratively reviews the literature on the effects of various commonly used IF strategies on body weight and body composition when compared to traditional DCR approaches, and draws conclusions for their practical application. A specific focus is provided as to the use of IF in combination with regimented exercise programs and the associated effects on fat mass and lean mass.