A Smartphone App Reveals Erratic Diurnal Eating Patterns in Humans that Can Be Modulated for Health Benefits

Creatine-mediated ferroptosis inhibition is involved in the intestinal radioprotection of daytime-restricted feeding

Ionizing radiation-induced intestinal injury (IRIII) is a catastrophic disease lack of sufficient medical countermeasures currently. Regulation of the gut microbiota through dietary adjustments is a potential strategy to mitigate IRIII. Time-restricted feeding (TRF) is an emerging behavioral nutrition intervention with pleiotropic health benefits. Whether this dietary pattern influences the pathogenesis of IRIII remains vague. We evaluated the impact of TRF on intestinal radiosensitivity in this study and discovered that only daytime TRF (DTRF), not nighttime TRF, could ameliorate intestinal damage in mice that received a high dose of IR. Faecal metagenomic and metabolomic studies revealed that the intestinal creatine level was increased by approximate 9 times by DTRF, to which the Bifidobacterium pseudolongum enrichment contribute. Further investigations showed that creatine could activate the energy sensor AMP-activated protein kinase in irradiated enterocytes and induce phosphorylation of acetyl-CoA carboxylase, resulting in reduced production of polyunsaturated fatty acids and reduced ferroptosis after IR. The administration of creatine mitigated IRIII and reduced bacteremia and proinflammatory responses. Blockade of creatine import compromised the ferroptosis inhibition and mitigation of DTRF on IRIII. Our study demonstrates a radioprotective dietary mode that can reshape the gut microbiota and increase intestinal creatine, which can suppress IR-induced ferroptosis, thereby providing effective countermeasures for IRIII prevention.

Efficacy of time restricted eating and resistance training on body composition and mood profiles among young adults with overweight/obesity: a randomized controlled trial

BACKGROUND/OBJECTIVE

Dietary restriction or exercise regimens can promote weight loss or physical fitness among patients with obesity. However, intervention-associated adverse effects may impede patients' motivation to participate in dietary/exercise interventions. We examined the effects of time restricted eating (TRE) with or without resistance training (RT) on body composition, mood profile, and sleep quality in young college adults with overweight or obesity.

METHODS

Fifty-four young college students with overweight/obesity were randomized into control (CON), TRE, RT, and TRE plus RT (TRE+RT) trials. The TRE trials restricted to an eating window of 10-hour/day for 8-week. The RT trials performed supervised resistance exercise, while the control trial maintained a regular lifestyle. Changes in body composition variables, blood pressure, mood status, and sleep quality were measured before and after the intervention.

RESULTS

TRE intervention alone or in combination with RT significantly (p < 0.01) decreased body weight (>2 kg) and BMI (~1 kg/m2) in adults with overweight/obesity. Both RT alone and combined with TRE substantially decreased fat mass by 1.1 ± 0.5 and 3.2 ± 0.4 kg, respectively. The decreased fat mass was greater in the combination trial than in the RT trial, whereas TRE alone had no effect. In contrast, fat-free mass was significantly (p < 0.01) decreased with TRE (-2.3 ± 06 kg), increased with RT (1.6 ± 0.3 kg), and was stably maintained with combination interventions. The reduced waist and hip circumferences in the TRE (p < 0.01) were similar to those in the TRE+RT trials, however, RT alone had no effect. Time and group interaction showed a large effect size (partial eta squared) for all body composition variables. In addition, RT with or without TRE notably decreased diastolic blood pressure (RT: -5.5 ± 1.9 mmHg, TRE+RT: -4.1 ± 1.5 mmHg, p < 0.05). Mild anxiety levels at baseline in RT (4.8 ± 2.6) and TRE+RT (4.1 ± 3) trials were found to be normal at postintervention in TRE+RT (3.6 ± 1.7) but not in RT (5.6 ± 3.5). No depression or stress was recorded among the participants during the intervention. The reported poor sleep quality among participants at baseline was significantly improved with RT (4.8 ± 2.9; p < 0.05), and tended to improve with TRE+RT interventions (4.5 ± 1.9).

CONCLUSIONS

10-hour TRE is beneficial for weight/fat loss without affecting mood status. However, TRE combined with RT might be more effective for weight/fat loss, maintaining muscle mass, and good quality of sleep among young adults with overweight or obesity.

Early time-restricted eating with energy restriction has a better effect on body fat mass, diastolic blood pressure, metabolic age and fasting glucose compared to late time-restricted eating with energy restriction and/or energy restriction alone: A 3-month randomized clinical trial

BACKGROUND & AIMS

Time-restricted eating (TRE) has attracted increasing attention from researchers and the public. Recent studies suggest that the combination of TRE with energy restriction (ER) may have more favourable effects on both physical and biochemical aspects compared to ER alone. The aim of the present 3-month intervention study was to determine the effects of an 8-h early time-restricted eating and an 8-h late time-restricted eating with ER (eTRE + ER and lTRE + ER) compared to 12-h ER alone on body mass and other anthropometric and cardiometabolic risk factors in participants with overweight and obesity.

METHODS

Participants (n = 108) were allocated to three different groups according to their personal chronotype: eTRE + ER (37 participants), lTRE + ER (37 participants) and ER (34 participants). Ninety-three participants completed the entire 3-month intervention (34 in eTRE + ER, 28 in lTRE + ER and 31 in ER). Anthropometric and cardiometabolic risk factors were measured at baseline and after 1, 2 and 3 months of the intervention. Sleep quality and quality of life were assessed at baseline and after 3 months of the intervention. ER was determined based on the individual's resting metabolic rate. Effects were analyzed using the per-protocol approach.

RESULTS

Results showed a significant time main effect (p < 0.001), suggesting a decrease in body mass at the end of the 3-month intervention with a mean loss of -5.0 kg (95 % CI, -5.7, -4.3) for the eTRE + ER group, -4.4 kg (95 % CI, -5.2, -3.6) for the lTRE + ER group and -4.3 kg (95 % CI, -5.0, -3.6) for the ER group, with no significant difference between the groups (p = 0.319). eTRE + ER had greater improvements in fat mass (-1.2 % (95 % CI, -2.1, -0.2), p = 0.013) and fasting glucose (-0.35 mmol/L (95 % CI, -0.63, -0.06), p = 0.012) than participants in the lTRE + ER group and greater improvements in fat mass (-1.1 % (95 % CI, -2.0, -0.1), p = 0.022), metabolic age (-3 years (95 % CI, -5, -0), p = 0.028) and diastolic blood pressure (-4 mmHg (95 % CI, -8, -0), p = 0.033) than the participants in the ER group. No significant changes were found between the groups for the other parameters measured.

CONCLUSIONS

There was no difference in body mass between the eTRE + ER, lTRE + ER and ER groups after 3 months of intervention. However, eTRE + ER showed a greater benefit for fasting blood glucose, certain anthropometric parameters and diastolic blood pressure compared to lTRE + ER and/or ER alone. Other anthropometric, biochemical and health-related parameters were not affected by eating window.

TRIAL REGISTRATION

https://clinicaltrials.gov/study/NCT05730231.

Navigating nutrients: A scoping review on real-time food nutrition classification and recommendation systems

In an era where fast-paced lifestyles often conflict with the pursuit of healthy eating, the demand for innovative solutions to aid nutritional decision-making has never been more pressing. Real-time food nutrition classification and recommendation systems offer an effective solution to this growing issue. By harnessing state-of-the-art technologies such as sensor-based data collection and machine learning algorithms, these systems can conduct a precise analysis of the nutritional composition of foods. This scoping review presents a comprehensive investigation of real-time food nutrition recommendation and classification systems, encompassing their capabilities, effectiveness, and potential ramifications for public health, focusing on identifying and evaluating the technological approaches, nutritional parameters, and applications of these systems. By synthesizing prior research, we can reveal the complex web of methodologies, trends, and obstacles that influence this ever-evolving discipline. We included only peer-reviewed studies and conference proceedings, published within the last decade. A systematic search of Scopus, IEEE Xplore, and PubMed databases yielded 166 papers, of which 36 studies were selected for further evaluation. The findings highlight the importance of technological advancements and the need for further research to improve the effectiveness of these systems in promoting healthy eating habits. The study unveils a landscape filled with possibilities, from machine learning algorithms to sensor-based technologies, each offering unique pathways for users to make smart dietary decisions on the go.

Development and validation of a protocol to determine product perception in relation to the moment of the day

Chronotype refers to an individual's tendency to engage in activities either earlier or later, in alignment with the biological rhythm of their body and its interaction with the environmental cycle. Chronotypes influence food preferences and meal timing, yet most studies rely solely on questionnaires without integrating real-time tasting data. To address this gap, we developed and validated a method to measure sensory perception and examine its variations throughout the day in alignment with circadian rhythms. Fifty-two university students completed the Munich Chronotype Questionnaire and, over four days within a week, they participated in sensory evaluations using a web-based questionnaire. At four daily time slots (morning, midday, afternoon, evening), participants tasted candies and assessed some sensory attributes-sweetness, sourness, bitterness, freshness, and overall flavor-using the Rate-All-That-Apply method. Before each evaluation, they also reported their level of hunger, thirst, tiredness, and willingness to complete the task. Reminders were sent via pre-programmed messages to ensure adherence to the schedule. The results demonstrate the feasibility of the method, with low attrition rates and consistent participant motivation over the study period. Sensory perception was found to vary across the day and in relation to chronotype, highlighting the method's potential for advancing research in sensory chrononutrition.•A web-based questionnaire including tasting was developed to assess sensory perception at different times of the day over four days.•Perception was analyzed in relation to chronotype.•Face validity was confirmed, as significant variations based on chronotypes were observed.

Time-restricted eating increases hunger in adults with overweight and obesity: A systematic review and meta-analysis of randomized controlled studies

Time-Restricted Eating (TRE) is an intermittent fasting approach that holds promise in managing obesity and appears to influence hunger. We hypothesized that the effects of TRE would be due to a lower caloric intake imposed, as with any other type of dietary intervention. However, it remains unclear whether these effects are attributed to the chrononutrition protocol itself or the caloric restriction resulting from the intervention. Our primary aim was to examine the impact of TRE on hunger compared to isocaloric strategies in adults with overweight or obesity. We conducted a systematic review of randomized clinical trials, with inclusion criteria comprising adults aged 18 years and older with overweight/obesity. A literature search was conducted from the earliest available article up to January 2025, with no restrictions on time, region, or language. The search encompassed major electronic databases, including CENTRAL, MEDLINE, LILACS, EMBASE, Google Scholar, and OpenGrey. Of the 14 studies included, four met the eligibility criteria for the primary meta-analysis, which evaluated hunger in 323 participants. The findings revealed that TRE resulted in an increase in hunger (MD 2.05, 95% CI 1.46, 2.64; I² = 0%) compared to the isocaloric control group. In conclusion, the TRE protocol was associated with elevated hunger compared to isocaloric strategies, which may warrant further investigation into its long-term feasibility in weight loss programs.

Comparing the effectiveness of calorie restriction with and without time-restricted eating on the circadian regulation of metabolism: rationale and protocol of a three-arm randomised controlled trial in adults at risk of type 2 diabetes

Time-restricted eating (TRE) may extend the cardiometabolic health benefits of calorie restriction (CR). However, few studies have compared its effect on the circadian regulation of glucose metabolism and the optimal time of day to initiate TRE is also unclear. This study aims to compare the effectiveness of CR with and without TRE on glucose tolerance in response to 3 identical meals consumed over the day. A parallel, single-blinded, 3-arm randomised controlled trial will be conducted in 114 adults, aged 35 to 75 years with a BMI ≥25.1 but <45.0 kg/m2, elevated waist circumference and fasting blood glucose (≥5.6 mmol/L), and who score ≥12 on the Australian Type 2 Diabetes Risk Assessment tool. Participants will be stratified by sex and fasting blood glucose (≤6.0 mmol/L; >6.0 mmol/L) and then randomised (1:1:1) to CR (unrestricted meal timing), eCR (0800 to 1600) or dCR (1200-2000) for 8 weeks. The primary outcome is the change in the natural logarithm of the mean over 3 identical meals of the postprandial glucose area under the curve (AUC). The analysis will be performed using a covariate adjusted linear regression of the differences in postprandial glucose log AUC at 8 weeks from baseline. This randomised clinical trial will be the first to delineate the benefits of CR alone or in combination with time restricted eating on postprandial glucose metabolism over the day in adults at increased risk of type 2 diabetes.

Time-Restricted Feeding Promotes Longevity and Gut Health Without Fitness Trade-Offs

Time-restricted feeding (TRF), a dietary intervention involving daily fasting periods, has been associated with metabolic benefits; however, its long-term physiological impact remains unclear. Using Drosophila melanogaster as a model, we investigated the effects of a 16:8 TRF regimen on lifespan, reproductive output, gut health, and microbiota composition. TRF significantly extended lifespan, even when applied only during early adulthood. Notably, this longevity benefit occurred without compromising reproductive fitness, as measured by female fecundity in life's most crucial reproductive phase. TRF promoted gut homeostasis in aged flies by reducing intestinal stem cell proliferation and enhancing epithelial barrier integrity. Furthermore, TRF induced a shift in microbiota composition, increasing the prevalence of gram-negative bacterial taxa. These results show that even short-term TRF interventions at a young age can have long-term physiological benefits. Metabolic reprogramming or increased autophagy are the most likely mechanisms mediating the health-promoting effects of this type of nutritional intervention. TRF is an effective, non-invasive strategy for promoting healthy longevity without significant adverse effects on other aspects of life.

Is the Underreporting of Energy Intake Associated with Chrononutritional and Clinical Parameters During Pregnancy?

INTRODUCTION

Underreporting of food intake corresponds to distortions in self-reported food consumption and can lead to inadequacies in dietary prescriptions, which play an important role in preventing excessive weight gain during pregnancy. Recent studies in the field of chrononutrition indicate that meal times influence the quality, quantity, and distribution of calories throughout the day.

OBJECTIVE

To evaluate the association of energy intake underreporting with chrononutritional and clinical variables throughout pregnancy.

MATERIAL AND METHODS

Prospective cohort study carried out with 100 pregnant women followed up in the three gestational trimesters. Food intake assessment was conducted using three 24-h dietary recalls. Chrononutritional variables evaluated included eating duration, overnight fasting, timing of first and last meals, and the number of eating episodes. The clinical variables evaluated were the adequacy of weight gain and fasting glucose. The occurrence of underreporting was calculated using the Goldberg method and the pregnant women were categorized into three groups: Underreporters (UR), Potential Underreporters (PUR) and Normal Reporters (NR). Generalized estimating equations (GEE) adjusted for confounders were used to assess the association between three groups of levels of energy notification (independent variables) and chrononutritional and clinical variables (dependent variables) throughout pregnancy.

RESULTS

Underreporters group reported having first meal later (mean ± standard error: UR-9:26 ± 0:11 vs PUR-8:34 ± 0:09 and NR-8:32 ± 0:08), last meal earlier (UR-19:47 ± 0:10 vs PUR-20:17 ± 0:07 and NR-20:46 ± 0:08), shorter eating duration (UR-10:22 ± 0:14 vs PUR-11:43 ± 0:12 and NR-12:12 ± 0:12), longer overnight fasting (UR-10:58 ± 0:08 vs PUR-10:30 ± 0:08 and NR-10:05 ± 0:08), lower number of eating episodes (UR-4.16 ± 0.13 vs PUR-4.90 ± 0.12 and NR-5.11 ± 0.12), exhibited higher fasting glucose (UR-80.33 ± 1.30 vs NR-74.45 ± 1.90) during pregnancy and greater excessive weight gain in the third trimester (UR-2.20 ± 0.26 vs NR-1.58 ± 0.19).

CONCLUSION

Distinct chrononutritional patterns observed in women who underreported food intake suggest that underreporting is associated not only with overall food intake but also with meal patterns, particularly the timing of the first and last meals of the day. Further studies are needed to validate this hypothesis.

Advancing Chrononutrition for Cardiometabolic Health: A 2023 National Heart, Lung, and Blood Institute Workshop Report

The circadian system maintains optimal biological functions at the appropriate time of day, and the disruption of this organization can contribute to the pathogenesis of cardiometabolic disorders. The timing of eating is a prominent external time cue that influences the circadian system. "Chrononutrition" is an emerging dimension of nutrition and active area of research that examines how timing-related aspects of eating and nutrition impact circadian rhythms, biological processes, and disease pathogenesis. There is evidence to support chrononutrition as a form of chronotherapy, such that optimizing the timing of eating may serve as an actionable strategy to improve cardiometabolic health. This report summarizes key information from the National Heart, Lung, and Blood Institute's virtual workshop entitled "Chrononutrition: Elucidating the Role of Circadian Biology and Meal Timing in Cardiometabolic Health," which convened on May 2 to 3, 2023, to review current literature and identify critical knowledge gaps and research opportunities. The speakers presented evidence highlighting the impact on cardiometabolic health of earlier and shorter eating windows and more consistent day-to-day eating patterns. The multidimensionality of chrononutrition was a common theme, as it encompasses multiple facets of eating along with the timing of other behaviors including sleep and physical activity. Advancing the emerging field of chrononutrition will require: (1) standardization of terminology and metrics; (2) scalable and precise tools for real-world settings; (3) consideration of individual differences that may act as effect modifiers; and (4) deeper understanding of social, behavioral, and cultural influences. Ultimately, there is great potential for circadian-based dietary interventions to improve cardiometabolic health.

Time-restricted eating improves appetite regulation and sleep characteristics in adults with poor sleep quality

BACKGROUND & AIMS

Time-restricted eating (TRE), a type of intermittent fasting (IF), appears to improve metabolic health in adults but shows inconsistent effects on appetite and sleep regulation, with less data on adults with poor sleep. Our study evaluated the impact of TRE on appetite and nighttime sleep in individuals with normal-weight and inadequate sleep.

METHODS

A randomized controlled trial involved 30 young (age: 25.7 ± 5.6 years; 21F), normal-weight (body mass index (BMI): 23.0 ± 1.8 kg/m2) adults with poor sleep (<7 h/night or poor quality). Participants were randomized to two groups for 8 weeks: i) control group (CON), maintaining usual eating habits (CON, n = 16) or ii) time-restricted eating group (TRE), following a self-selected 10-h eating window (mandatory fasting from 23:00 to 06:00) for 8 weeks with no dietary changes (TRE, n = 14). Appetite, satiety, and craving for food were assessed using Visual Analog Scales (VAS) and the Food Craving Inventory-SP (FCI-SP), respectively. Sleep duration and quality were evaluated by using the Pittsburgh Sleep Quality Index (PSQI) and 7-day actigraphic recordings.

RESULTS

The TRE group reported higher satiety and fullness feeling together with a lower capacity to eat compared to CON (p < 0.038), while overall craving scores showed no between-group differences (p = 0.381). Sleep duration did not differ between groups, whereas several sleep characteristics improved. After TRE intervention, actigraphic assessments revealed an earlier sleep onset and later wake-up time (both p < 0.001) and fewer movements during sleep (p < 0.025).

CONCLUSION

An 8-week, 10-h TRE protocol positively affects appetite regulation and sleep characteristics in normal-weight young adults with insufficient or poor sleep. TRE appears promising for addressing appetite regulation and sleep disturbances in this group.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT06485037).

Effects of time-restricted eating with exercise on body composition in adults: a systematic review and meta-analysis

BACKGROUND

The effects of time-restricted eating (TRE) with exercise on body composition in adults are not clear.

OBJECTIVE

This meta-analysis aimed to assess the effects of TRE when followed in combination with various forms of exercise, including aerobic, resistance, and combined aerobic and resistance [concurrent] training on body composition.

METHODS

Studies published up to May 2023 were searched in EBSCOhost (MEDLINE, CINAHL, SPORTSDISCUS), PubMed, and SCOPUS databases. Fifteen studies, including 338 participants, that evaluated TRE vs. unrestricted eating in individuals performing exercise were analyzed. A random-effects model was used to calculate the weighted mean effect sizes (ES) with 95% confidence intervals (95% CI's).

RESULTS

According to the pooled results, TRE had a small but significant reduction of fat mass (FM) kg with an effect size of -0.20 (95% CI = -0.28 to -0.13, p < 0.001) and on body fat percent (BF%) with an effect size of -0.23 (95% CI = -0.35 to -0.11, p < 0.001). The prediction interval ranged from -0.48 to 0.08 for FM and from -0.64 to 0.18 for BF%, respectively. TRE did not significantly alter fat-free mass (FFM) kg compared to control (p = 0.07). Furthermore, age, body mass index (BMI), exercise type, study duration, and energy intake did not have a significant impact on the variation in effect sizes according to the subgroup analyses (p > 0.05).

CONCLUSION

TRE with exercise may reduce fat mass compared to an unrestricted eating window exercise-matched control while preserving FFM. However, more studies are needed.

Later eating timing in relation to an individual internal clock is associated with lower insulin sensitivity and affected by genetic factors

BACKGROUND

Although the contribution of the circadian clock to metabolic regulation is widely recognized, the role of eating timing in glucose metabolism and diabetes risk remains insufficiently studied. This study aimed (i) to investigate the link between the eating timing pattern relative to individual clock and glucose homoeostasis and (ii) to explore the contribution of genetic and environmental factors to eating timing parameters.

METHODS

In 92 adult twins (NCT01631123), glycaemic traits were assessed using the oral glucose tolerance test. Parameters of eating timing pattern (eating timing itself, daily calorie distribution, and eating frequency) were extracted from five-day food records. Caloric midpoint defined as the time point at which 50% of daily calories are consumed. Circadian timing of eating was determined as a time interval between the clock time of eating and a corrected midpoint of sleep, a chronotype marker. Heritability of eating timing components was estimated by comparing correlations within monozygotic and dizygotic twin pairs and fitting genetic structural equation models.

FINDINGS

Among components of eating timing, the most associations were found for the circadian time of caloric midpoint (CCM). Later CCM was significantly associated with poorer insulin sensitivity, i.e. with lower ISI Stumvoll (β = 0.304, p = 5.9 × 10-4) and higher HOMA-IR (β = -0.258, p = 0.011) indices, as well as with higher fasting insulin levels (β = -0.259, p = 0.013), even after the model adjustment for sex, age, daily energy intake, and sleep duration. Later CCM also demonstrated robust associations with higher BMI and waist circumference. All eating timing components showed high or moderate heritability and were strongly related to individual sleep timing.

INTERPRETATION

Later eating timing in relation to an individual internal clock is associated with lower insulin sensitivity. Shifting the main calorie intake to earlier circadian times may improve glucose metabolism, but genetic factors could influence the feasibility and effectiveness of eating-timing based interventions. The findings should be investigated in a larger cohort.

FUNDING

This work was supported by the German Research Foundation (DFG RA 3340/4-1 to OP-R, project number 530918029), by the European Association for the Study of Diabetes (Morgagni Prize 2020 to OP-R), and by the German Federal Ministry of Education and Research (BMBF NUGAT 0315424 to AFHP). The DZD is funded by the German Federal Ministry for Education and Research (01GI0925).

The effects of chrononutrition, chronotype and sleep behavior variabilities on adiposity traits and appetite sensations among students and staff of a Malaysian university

We investigated the association of chrononutrition, sleep behavior, and chronotype with adiposity and appetite sensations among 220 Malaysian adults (M/F = 57/163; aged 22.02   ±   5.19). Meal times, dietary intake, and appetite sensations (before and after meals) were recorded for two weekdays and one weekend. Sleep behavior was tracked objectively via activity wristband, chronotype was assessed by the Morningness-Eveningness Questionnaire, and anthropometrics/body compositions were measured. Overall participants had significantly later breakfast, lunch, eating midpoint, wake up time, sleep duration, compared to weekdays. Those who belonged to the delay eating jetlag group had significantly higher weekday, but lower weekend eating windows. Larger caloric intake later in the day was significantly associated with lower body mass and adiposity. Delay lunch jetlag class was significantly associated with higher waist-hip ratio. Delayed morning and afternoon chrononutrition behaviors were associated with higher hunger and eating thoughts, and lower fullness sensations pre- and post-meals. Morningness was associated with lower satisfaction and fullness sensations post-breakfast, but higher same sensations pre-dinner. In conclusion, larger caloric intake later in the day and advanced lunch jetlag led to lower adiposity, while delayed chrononutrition behaviours were associated with higher pre- and post-meal appetite sensations.

Associations of >1-h compared with 1-h meal timing variability (eating jetlag) with plasma glycemic parameters and continuous glucose monitoring measures among pregnant females: a prospective cohort study

BACKGROUND

Eating jetlag (EJL), the difference in eating times between weekdays and weekends, disrupts circadian alignment and may affect metabolic health. However, its influence on glucose tolerance and continuous glucose monitoring (CGM) during pregnancy remains unknown.

OBJECTIVES

We aimed to investigate the associations between EJL and glycemic parameters during pregnancy.

METHODS

This secondary analysis was conducted on a cohort of 248 healthy pregnant females from Singapore. EJL, derived from 4-d food diaries at 20-wk of gestation, was the absolute difference in average meal times between weekdays and weekends for the first (EJLfirst) and last (EJLlast) meals and categorized as ≤1-h (reference) or >1-h. Primary outcomes at 25-wk of gestation included results from the 75-g oral glucose tolerance test, fasting insulin, homeostasis model assessment of insulin resistance (HOMA2-IR), and β-cell function (HOMA2-%B). Secondary outcomes at 20-wk of gestation included glycemic control and variability measured over 10-d using CGM. Skewed glycemic variables were log-transformed for normality, and associations between EJL and glycemic outcomes were analyzed using multivariable regressions.

RESULTS

After adjusting for baseline sociodemographic, lifestyle, and dietary factors, EJLlast >1-h was associated with higher fasting insulin [geometric mean ratio (95% confidence intervals): 1.21 (1.05, 1.39)], HOMA2-IR [1.21 (1.05, 1.39)], HOMA2-%B [1.11 (1.01, 1.22)], and CGM-based measures, including mean glucose [1.05 (1.00, 1.09)], J-index [1.11 (1.01, 1.22)], and glucose management indicator [1.03 (1.00, 1.06)]. EJLfirst >1-h was associated with higher CGM-based mean amplitude of glycemic excursions (MAGE) [1.09 (1.01, 1.19)]. For CGM-based glycemic variability outcomes (standard deviation, coefficient of variation [CV], MAGE), there were interactions between EJLfirst and 1) diet quality [adherence to Dietary Approaches to Stop Hypertension (DASH)] (P-interactions = 0.06-0.09), and 2) prepregnancy body mass index (BMI) (P-interaction=0.07 for CV). In females with a prepregnancy BMI ≥23 kg/m2 and low diet quality (DASH score ≤median), EJLfirst >1 h was associated with higher CGM-based glycemic variability.

CONCLUSIONS

EJL was associated with unfavorable glycemic parameters during pregnancy. Dietary interventions could promote consistent meal timing, especially in higher risk groups with suboptimal nutritional status. This trial was registered at clinicaltrials.gov as NCT03803345.

Chrononutritional Patterns: Examining the Interaction Between Shift Work, Eating Habits and Mealtimes in Shift Workers

PurposeTo analyze the effect of shift work on the total calorie intake, macronutrients and mealtimes of military policemen during working days and off-duty days.DesignQuantitative cross-sectional.SettingMilitary policemen who worked shifts in a city in the Northern region of Brazil.Population34 military policemen aged between 18 and 50.MeasurementsCalorie intake, macronutrients, mealtimes, dietary midpoint and dietary window for working days and off-duty days were analyzed. Generalized Estimation Equations (GEE) with Bonferroni post-test, adjusted for age and BMI test was used to check the differences between the variables.ResultsThe median intake of calories (2781 kcal vs 2350 vs 2295 kcal; P < 0.001), proteins (200 g vs 122.65 g vs 104.24 g; P = 0.006) and lipids (158.41 g vs 86.94 g vs 91.03 g; P = 0.014) was higher when policemen worked day compared night shifts and to off-duty days. Meals started early during the day and the eating window was longer during the day shift, followed by off-duty days and the night shift.ConclusionThese findings reinforce the effect of shift work on eating habits and highlight the need for nutritional strategies adapted to the occupational context of military policemen.

Effect of Time-Restricted Eating on Sleep Quality and Body Composition: A Systematic Review

CONTEXT

Time-restricted eating (TRE) is a dietary approach that consolidates energy intake in a restricted period during the day. It is an alternative approach to weight loss and might be important to sleep quality.

OBJECTIVE

To review the current literature related to the effects of TRE on sleep quality and body composition in adults.

DATA SOURCES

A literature search of the PubMed, Scopus, Web of Science (Clarivate), and Biblioteca Virtual em Saúde/Bireme databases was carried out until May 2024.

DATA EXTRACTION

Reviewed articles included clinical, interventional (controlled or uncontrolled) studies including individuals older than 18 years, with no gender restriction. The interventions had to control feeding time, body composition could be assessed by any validated method, and sleep could be assessed by polysomnography, actigraphy, and validated sleep assessment questionnaires.

DATA ANALYSIS

Eleven studies were included in this systematic review. Study samples varied between 19 and 137 participants, with a predominance of female participants in 10 studies. Seven of the studies (58.3%) tested an intervention of 8 hours of TRE, with an intervention range of between 4 weeks and 12 months. All studies observed weight loss. Nine studies showed reductions in fat mass, including 2 studies that observed reductions in visceral fat mass. No studies, independently of weight loss or body composition changes, objectively observed changes in sleep duration after TRE interventions. However, in the subjective evaluation, 1 study found a reduction in sleep duration of 30 ± 13 minutes, an increase in latency of 7 ± 3 minutes, and a reduction in sleep efficiency of 2% ± 1% in the group treated with TRE compared with the control group.

CONCLUSION

Time-restricted eating seems to be effective in weight loss and fat mass reduction, but most studies found no effect on sleep parameters. There was a lack of standardized methods for sleep measurements in the reviewed studies. However, these results could provide valuable data for the design and formulation of new well-founded studies assessing sleep using objective methods and including different sleep parameters.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration No. CRD42024524598.

Association of meal timing with adiposity measures and gut microbiome characteristics in a cohort study: the Hispanic Community Health Study/Study of Latinos

BACKGROUND

Time-restricted eating may help control weight through caloric restriction, circadian rhythm, or influence on the gut microbiome (GMB). Physical activity (PA) also plays a role, as people with a longer eating window (EW, time between first and last daily intake) may be more active. The associations between meal timing, adiposity, PA, sedentary behavior (SB), and GMB characteristics are of interest in Hispanic/Latino persons, who experience a high burden of cardiometabolic diseases.

OBJECTIVES

We explored the relationship of EW with energy intake and accelerometer-measured activity and assessed whether a longer EW and later midpoint of intake (MOI, midpoint time of intake) are associated with adiposity and GMB differences in Hispanic/Latino adults.

METHODS

Using data from the prospective Hispanic Community Health Study/Study of Latinos (n = 11,778 participants with valid 24-h dietary recall and accelerometer data, no unplanned weight loss, and BMI ≥ 18.5 kg/m2; n = 1925 with GMB data), we explored the relationship between EW, SB, and energy intake. We used multivariable linear regression models to study the relationship between EW or MOI and adiposity measures and GMB characteristics, adjusted for clinical, behavioral, and demographic characteristics.

RESULTS

Those with longer EW tended to have less SB and greater energy intake, suggesting that some individuals may balance greater intake with greater expenditure. After adjustments including energy balance, each hour of EW was associated with 0.29% higher BMI (95% confidence interval [CI]: 0.07, 0.51; P = 0.011). Longer EW and caloric EW (EWC, EW, caloric meals only) were associated with several obesity-associated GMB taxa, such as Streptococcus (enriched, β: 0.04; 95% CI: 0.01, 0.07, for EW). MOI was not significantly associated with adiposity or GMB characteristics.

CONCLUSIONS

Shorter EW may promote healthy weight, but some individuals with longer compared with shorter EWs tend to have greater activity that could balance their greater energy intake. EW and EWC may influence GMB characteristics.

Time-restricted eating to address persistent cancer-related fatigue among cancer survivors: a randomized controlled trial

PURPOSE

Time-restricted eating (TRE) helps regulate rest-activity rhythms, blood glucose, and other diurnally regulated energetics processes, which may have implications for persistent fatigue. In a randomized controlled trial, we tested the effects of TRE vs. control on fatigue in cancer survivorship.

METHODS

Adult cancer survivors were recruited who were 2 months to 2 years post-treatment and reported moderate to severe fatigue. Participants were randomized 1:1, TRE:control, and all received individualized nutrition counseling. The TRE group self-selected a 10-h eating window for 12 weeks. At baseline, week 6, and week 12, participants were asked to log eating instances, complete the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire (FACIT-F, higher score = less fatigue), and wear an actigraph and continuous glucose monitor.

RESULTS

Thirty participants completed baseline assessments and were randomized (77% female, 53% Black/African American, 43% White, 7% Hispanic; 54.1 ± 14.7 years old; 87% with blood cancer); 25 completed 12-week assessments. TRE led to a meaningful reduction in fatigue at week 12 controlling for baseline levels (change in FACIT-F fatigue subscale = 0.0 ± 5.4 for control, 4.1 ± 5.7 for TRE, p = 0.11, effect size (ES) = 0.70; clinically meaningful threshold = 3.0 points). Glucose parameters (e.g., average interstitial glucose, average fasting glucose) tended to be lower, and rest-activity rhythms tended to indicate more regularity for those in the TRE vs. control group at weeks 6 and 12, though differences were not statistically significant (p > 0.19).

CONCLUSIONS

A 12-week, nutritionist-led TRE program led to less fatigue than control. Continued study of TRE patterns are warranted to optimize this eating pattern and address persistent cancer-related fatigue.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05256888.

Time-restricted eating, caloric reduction, and unrestricted eating effects on weight and metabolism: a randomized trial

OBJECTIVE

Metabolic improvements may precede weight loss. We compared the effects of self-selected 8-h time-restricted eating (TRE), 15% caloric restriction (CR), and unrestricted eating (UE) on weight, body composition, caloric intake, glycemic measures, and metabolic flexibility.

METHODS

In this 12-week randomized-controlled trial, we measured weight (primary outcome), body composition (dual-energy x-ray absorptiometry/magnetic resonance imaging), caloric intake (24-h recall), metabolic flexibility (indirect calorimetry during hyperinsulinemic-euglycemic clamp), and glycemic measures (hemoglobin A1c, hyperinsulinemic-euglycemic clamp, continuous glucose monitoring).

RESULTS

Of the 88 enrolled participants, 81 (92%) completed the trial (mean [SD], age, 43.2 [10.5] years, BMI, 36.2 [5.1] kg/m2; 54.5% female, 84.1% White). Final eating windows were 9.8 h (95% CI: 9.0 to 10.6) for TRE, 12.9 h (95% CI: 11.9 to 13.9) for CR, and 11.8 h (95% CI: 11.0 to 12.7) for UE. Compared with UE (n = 29), weight changes were -1.4 kg (95% CI: -4.5 to 1.7; p = 0.53) with TRE (n = 30) and -2.5 kg (95% CI: -5.8 to 0.8; p = 0.18) with CR (n = 29). TRE showed lower metabolic flexibility than CR (-0.041 [95% CI: -0.080 to -0.002]). Weight, body composition, caloric intake, and glycemic measures were similar among groups. Eating window reduction correlated with decreased caloric intake and visceral fat.

CONCLUSIONS

In a 12-week intervention, TRE did not lead to significant improvements in weight, average body composition, or glycemic or metabolic measures compared with CR or UE.

Combined effects of time-restricted eating and exercise on short-term blood glucose management in individuals with Type 2 Diabetes Mellitus: The TREx study, a randomised controlled trial

AIMS

Time-restricted eating (TRE) is a chrono-nutrition strategy where the daily 'eating window' is reduced to 8-10 h. We investigated the acute (14-h) effects of TRE, with and without post-meal exercise, on blood glucose and insulin concentrations in people with type 2 diabetes mellitus.

METHODS

Fourteen participants (5 F, 9 M; HbA1c: 7.6 ± 1.0%) completed four conditions in this randomised crossover study: CON (eating window, 0800-2000 h), CON with exercise (CON + Ex; 0800-2000 h + 15 min walking at 60% VO2peak, 45 min post-meal), TRE (eating window 1000-1800 h), and TRE with exercise (TRE + Ex, 1000-1800 h + 15 min walking as per CON + Ex), with standardised meals. Venous blood samples were collected at 26-timepoints and analysed for glucose and insulin concentrations. Statistical analysis used linear mixed-effects models with P < 0.05.

RESULTS

Reducing the eating window had little effect on plasma glucose 14-h area under the curve (AUC). Exercise reduced insulin 14-h AUC (P=0.01) with no additive effect of TRE.

CONCLUSION

Post-meal exercise lowered 14-h insulin AUC, neither 8-h TRE nor post-meal exercise altered 14-h blood glucose compared with 12-h eating window. Future work should focus on long-term effects of TRE combined with exercise for enhancing blood glucose in people with type 2 diabetes mellitus.

Does the timing and frequency of meals impact caloric and macronutrient intake in pregnant women?

This study aimed to investigate the correlation between chrononutritional parameters and daily total energy as well as macronutrient intake throughout different stages of pregnancy. A prospective cohort study was conducted with 100 pregnant women. Data was collected at each gestational trimester. Food intake data was accessed through three 24-hour dietary recalls in every trimester. Chrononutritional parameters, such as meal and snack times, eating duration, number of eating episodes, caloric midpoint, sleep end-first meal interval, last meal-sleep onset interval, were used to infer meal timing. Linear regression modeling analyses, adjusted for confounding factors, were carried out to investigate associations between each chrononutritional parameter (independent variables) and total daily energy and macronutrient intake (dependent variables) during each gestational trimester. Positive associations were observed between total energy intake, proteins, and carbohydrates with dinner time during the first and third trimesters (with the exception of protein intake in the third trimester). Total fat intake and dinner time showed a positive association throughout all gestational trimesters. Additionally, positive associations were found between total energy intake, fat, and carbohydrates with eating duration and the number of eating episodes in all gestational trimesters. Furthermore, correlations of dinner time, eating duration and number of eating episodes with energy intake were found, suggesting that pregnant women who ate later and more frequently tended to consume higher calorie amounts. In conclusion, our findings suggest that chrononutritional parameters associated with late eating are linked to increased total energy intake during pregnancy. If these results are confirmed, nutritional guidelines should not only focus on what or how much is consumed during pregnancy but also consider the timing of meals.

Association of meal time patterns with dietary intake and body mass index: a chrononutrition approach from NHANES 2017-2018

BACKGROUND

Chrononutrition studies suggest that eating later and extending the eating window are linked to higher energy intake and obesity. However, the relationship between chrononutrition variables and dietary intake, as well as with BMI, is still little explored at a population level. This study explored how chrononutrition variables relate to dietary intake and BMI at a population level.

METHODS

We analyzed data from the NHANES 2017-2018, including 2937 participants aged 18 years or older. Dietary intake was assessed by two 24-h dietary recalls. Caloric midpoint, eating window duration, sleep end-first meal and last meal-sleep onset intervals were determined by mealtime.

RESULTS

The findings indicate a trend of increased total consumption of energy (kcal) (p < 0.001; p < 0.001; p < 0.001; p < 0.001), carbohydrates (g) (p = 0.001; p < 0.001; p < 0.001; p < 0.001); protein (g) (p < 0.001; p = 0.008; p < 0.001; p < 0.001), fat (g) (p < 0.001; p = 0.007; p < 0.001; p < 0.001), and sugar (g) (p < 0.001; p < 0.001; p < 0.001; p < 0.001) as the sleep end-first meal interval decreases and the last meal-sleep onset interval, eating window, and energy intake after 8 pm increases, respectively. In addition, our findings suggest a trend of increased BMI in the group with BMI ≥ 30 kg/m² (p = 0.018) as sleep end-first meal interval increases and in the group with BMI < 25 kg/m² (p = 0.006) as the eating window increases.

CONCLUSION

Our findings suggest that eating later and having longer eating window are associated with higher dietary intake and higher BMI.

Late eating and shortened fasting are associated with higher ultra-processed food intake across all age groups: a population-based study

PURPOSE

Global dietary patterns are increasingly driven by ultra-processed foods-cheap, highly palatable, and ready-to-eat options. Exploring time-related eating patterns and its association with ultra-processed foods could help in intervention efforts, but knowledge on this topic is still limited. This study assessed the association of time-related eating patterns with unprocessed/minimally processed and ultra-processed food consumption across different life stages.

METHODS

Two 24-hour food recalls from a nationally representative sample in Brazil (Brazilian Household Budget Survey, POF, 2017-2018; n = 46,164) were used to estimate tertiles of first and last intake times, eating midpoint, caloric midpoint time, and night fasting (independent variables). All consumed foods were classified according to the Nova classification system, and the outcomes of interest were consumption of unprocessed/minimally processed and ultra-processed foods. Multiple linear regression models were performed for all individuals and stratified for each age group: adolescents (10-19 years, n = 8,469), adults (20-59 years, n = 29,332), and older individuals (≥ 60 years, n = 8,322).

RESULTS

The later tertile of first food intake time, last food intake time, caloric midpoint, and eating midpoint were positively associated with consumption of ultra-processed foods (β = 3.69, 95%CI = 3.04, 4.34; β = 1.89, 95%CI = 1.32, 2.47; β = 5.20, 95%CI = 4.60, 5.81; β = 3.10, 95%CI = 2.49, 3.71, respectively) and negatively associated with consumption of unprocessed or minimally processed foods (β=-2.79, 95%CI=-3.37; -2.22; β=-1.65, 95%CI=-2.24, -1.05; β=-3.94, 95%CI=-4.44, -3.44; β=- 2.35, 95%CI=-2.93, -1.78, respectively) compared to the first "earlier" tertile (reference). An inverse association was found for night fasting (β=-1.74, 95%CI=-2.28, -1.22 and β = 1.52, 95%CI = 0.98, 2.06 for ultra-processed and unprocessed/minimally processed foods, respectively). These associations were consistent across all age groups.

CONCLUSION

Chrononutrition patterns characterized by late intake timing and shortened overnight fasting were associated with higher consumption of ultra-processed foods and lower intake of unprocessed/minimally processed foods across all age groups.

NutriRAG: Unleashing the Power of Large Language Models for Food Identification and Classification through Retrieval Methods

Objective

This study explores the use of advanced Natural Language Processing (NLP) techniques to enhance food classification and dietary analysis using raw text input from a diet tracking app.

Materials and Methods

The study was conducted in three stages: data collection, framework development, and application. Data were collected via the myCircadianClock app, where participants logged their meals in free-text format. Only de-identified food-related entries were used. We developed the NutriRAG framework, an NLP framework utilizing a Retrieval-Augmented Generation (RAG) approach to retrieve examples and incorporating large language models such as GPT-4 and Llama-2-70b. NutriRAG was designed to identify and classify user-recorded food items into predefined categories and analyzed dietary patterns from free-text entries in a 12-week randomized clinical trial (RCT: NCT04259632). The RCT compared three groups of obese participants: those following time-restricted eating (TRE, 8-hour eating window), caloric restriction (CR, 15% reduction), and unrestricted eating (UR).

Results

NutriRAG significantly enhanced classification accuracy and effectively identified nutritional content and analyzed dietary patterns, as noted by the retrieval-augmented GPT-4 model achieving a Micro F1 score of 82.24. Both interventions showed dietary alterations: CR participants ate fewer snacks and sugary foods, while TRE participants reduced nighttime eating.

Conclusion

By using AI, NutriRAG marks a substantial advancement in food classification and dietary analysis of nutritional assessments. The findings highlight NLP's potential to personalize nutrition and manage diet-related health issues, suggesting further research to expand these models for wider use.

Association between Eating-Fasting and Sleep-Wake Cycles with Eating Times and Food Consumption throughout the Day: Longitudinal Study with Pregnant Women

Objective  To investigate the associations of the sleep-eating interval with eating times and food consumption throughout the day in pregnant women. Materials and Methods  A longitudinal study with 100 pregnant women treated at the public health network in the city of Uberlândia, state of Minas Gerais (MG), Brazil, during the entire gestational period. The time intervals between waking up and the first eating episode and between the last eating episode and going to sleep (independent variables) were investigated. Outcome measures were meal and sleep times, as well as food consumption throughout the day. Results  Food consumption closer to sleep at night is associated with higher total daily caloric intake in the first (β = -0.337, p  = 0.016) and second trimesters (Ts) of pregnancy (β = -0.240, p  = 0.023), and with longer sleep duration on weekdays ( p  < 0.05 for all three trimesters). We did not find associations between the wake-up to first eating episode interval and total calories ( p  > 0.05 for all three trimesters), but the longer this interval, the greater the percentage of calories at dinner (1T: β = 0.266, p  = 0.003; 2T: β = 0.269, p  = 0.045) and at the last meal (1T: β = 0.324, p  = 0.001; 2T: β = 0.231, p  = 0.033). Discussion  Taking longer to eat the first meal after waking up is associated with higher caloric intake later in the day, while taking longer to sleep after eating the last meal is associated with higher total daily caloric intake and shorter sleep duration, especially in the beginning and middle of pregnancy.

Impact of eating duration on weight management, sleeping quality, and psychological stress: A pilot study

The daily eating window significantly impacts weight and metabolic health, yet its ideal duration remains uncertain. Thirty-four healthy middle-aged women were randomly assigned to two intervention groups: 8-h time-restricted eating (TRE) and 14-h time-extended eating (EXE). Each intervention lasted 4 wk, with a 16-d washout period before switching to the other intervention. Clinical biomarkers were collected before and after each intervention, and sleep quality was assessed using the Korean Version of the Pittsburgh Sleep Quality Index (PSQI-K). Additionally, a daily visual analogue scale (VAS) was used to evaluate psychological changes. The TRE group experienced significant weight reduction, lower fasting plasma glucose and total serum cholesterol levels compared to the EXE group, but with an increase in systolic blood pressure. The EXE group showed improved blood pressure. The TRE group reported higher stress levels on the VAS, but the PSQI-K indicated improved sleep quality during the second intervention. An 8-h TRE, without calorie restriction or diet composition changes, proves more beneficial for weight management and plasma glucose control compared to the 14-h EXE among Korean women. Implementation of this approach is recommended to be gradual to mitigate psychological fluctuations and adverse blood pressure changes. The trial was registered with ClinicalTrials.gov (ID: NCT05964179) and Clinical Research Information Service (CRIS, Korea) (ID: KCT0008640).

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.

Predictive models of post-prandial glucose response in persons with prediabetes and early onset type 2 diabetes: A pilot study

OBJECTIVE

Post-prandial glucose response (PPGR) is a risk factor for cardiovascular disease. Meal carbohydrate content is an important predictor of PPGR, but dietary interventions to mitigate PPGR are not always successful. A personalized approach, considering behaviour and habitual pattern of glucose excursions assessed by continuous glucose monitor (CGM), may be more effective.

RESEARCH DESIGN AND METHODS

Data were collected under free-living conditions, over 2 weeks, in older adults (age 60 ± 7, BMI 33.0 ± 6.6 kg/m2), with prediabetes (n = 35) or early onset type 2 diabetes (n = 3), together with sleep and physical activity by actigraphy. We assessed the predictive value of habitual CGM glucose excursions and fasting glucose on PPGR after a research meal (hereafter MEAL-PPGR) and during an oral glucose tolerance test (hereafter OGTT-PPGR).

RESULTS

Mean amplitude of glucose excursions (MAGE) and fasting glucose were highly predictive of all measures of OGTT-PPGR (AUC, peak, delta, mean glucose and glucose at 120 min; R2 between 0.616 and 0.786). Measures of insulin sensitivity and β-cell function (Matsuda index, HOMA-B and HOMA-IR) strengthened the prediction of fasting glucose and MAGE (R2 range 0.651 to 0.832). Similarly, MAGE and premeal glucose were also strong predictors of MEAL-PPGR (R2 range 0.546 to 0.722). Meal carbohydrates strengthened the prediction of 3 h AUC (R2 increase from 0.723 to 0.761). Neither anthropometrics, age nor habitual sleep and physical activity added to the prediction models significantly.

CONCLUSION

These data support a CGM-guided personalized nutrition and medicine approach to control PPGR in older individuals with prediabetes and diet and/or metformin-treated type 2 diabetes.

The effect of mediterranean diet and chrononutrition on sleep quality: a scoping review

BACKGROUND

The relationship between diet and sleep quality is intricate, with growing evidence suggesting that dietary patterns and meal timing (chrononutrition) can significantly influence sleep outcomes. This scoping review aims to compare the impact of Mediterranean diet and chrononutrition methods on sleep variables, including sleep quality, duration, and efficiency. While the Mediterranean diet is renowned for its health benefits in chronic diseases, chrononutrition focuses on how the timing of food intake affects health and circadian biology.

METHODS

Literature search following PRISMA guidelines using PubMed and Google Scholar focused on Mediterranean diet and chrononutrition effects on sleep quality. Studies assessed sleep quality using subjective methods like Pittsburgh Sleep Quality Index, analyzing data on study type, sample size, age group, diet, duration, sleep parameters, and outcomes.

RESULTS

Thirty three studies met inclusion criteria, 24 focusing on Mediterranean diet and 9 on chrononutrition. Among the 24 Mediterranean diet studies, most of which were observational studies, 17 reported a positive association between adherence to Mediterranean diet and improved self-reported sleep quality, while the remaining studies found no significant association. In contrast, evidence supporting the positive effects of chrononutrition on sleep quality was limited, with only two out of nine studies having found improvement in sleep quality.

CONCLUSIONS

Mediterranean diet demonstrates a more consistent and positive influence on sleep quality compared to chrononutrition. However, a limitation of review is that the reviewed Mediterranean diet studies were mainly cross-sectional or observational, while the reviewed chrononutrition studies were mainly interventional trials. Larger interventional clinical trials are needed to determine optimal dietary strategies and meal timing for promoting healthy sleep.

Independent effects of the human circadian system and sleep/eating cycles on caloric intake in adolescents vary by weight status

Late-day eating is linked to increased obesity risk; however, whether the endogenous circadian system independently influences caloric intake and if this control differs among individuals based on weight status is unknown. Here, we investigated in adolescents the independent roles of the endogenous circadian system and of the behavioral sleep/wake cycle (sleep/wake, fasting/eating, rest/activity, dark/dim light, social interaction, posture, etc.) on self-selected caloric intake using a Forced Desynchrony protocol. Fifty-one male and female adolescents across three weight status categories (24 with healthy weight, 13 with overweight, and 14 with obesity) completed the protocol where participants lived on seven 28-h sleep/wake cycles in dim light during wake and complete darkness during sleep. Results suggest that the circadian system and the behavioral cycle each affected caloric intake, with a decrease across the wake episode and an increase from circadian morning to circadian evening in caloric intake. The endogenous circadian rhythm in caloric intake showed a circadian peak-to-trough difference of 196 [CI 95% 164, 226] kcal per meal with peak timing of 296° [288°, 304°; equivalent to ~17:30 in these participants]. In those with overweight/obesity, more calories were consumed later in the waking episode and later in the circadian cycle, and with blunted amplitudes compared to those with healthy weight. Results implicate both the endogenous circadian system and the behavioral cycle in shaping the daily rhythm of food intake. Furthermore, these results help explain the increased drive for caloric intake toward the evening, especially in those at risk for obesity.

Association between shift work and eating behaviours, sleep quality, and mental health among Italian workers

PURPOSE

Recent studies indicate that shift work may affect workers' eating habits and overall well-being. This study aimed to assess differences in eating patterns, sleep quality, and mental health between Italian shift and non-shift workers, with a focus on individual chronotype and the type of shift work (day vs. night shift).

METHODS

The cross-sectional study involved 322 subjects (166 shift and 156 non-shift workers). Eating habits were evaluated using a 7-day diary and the Medi-Lite questionnaire. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI), and mental health with the Depression Anxiety Stress Scales (DASS). Individual chronotype was defined using the Morningness-Eveningness Questionnaire.

RESULTS

No significant differences in daily energy, macronutrient, and micronutrient intake between the two groups, nor in the temporal pattern of eating. However, shift workers had significantly (p < 0.05) lower adherence to the Mediterranean diet (MD) (7.6 ± 2.3 vs 8.1 ± 2.2) compared to non-shift workers. Shift workers also reported significantly poorer sleep quality (mean PSQI score 7.6 ± 3.7 vs. 5.8 ± 3.0) and higher levels of anxiety and stress symptoms. Among shift workers, those with an evening chronotype had significantly lower MD adherence than those with a morning chronotypes. Additionally, night shift workers experienced more sleep disturbances compared to day ones.

CONCLUSION

Shift workers reported lower MD adherence, poorer sleep quality, and a higher prevalence of anxiety and stress symptoms compared to a similar group of non-shift workers. Evening chronotypes and night shift work were associated with worse eating habits and sleep quality.

Circadian Disruption and the Risk of Developing Obesity

PURPOSE OF THE REVIEW

This review summarizes recent evidence for a role of the clock in adipose tissue physiology and the impact of circadian desynchrony on the development of obesity.

RECENT FINDINGS

Circadian disruptions due to shift work, late time eating and nighttime light exposure are associated with obesity and its metabolic and cardiovascular consequences. Studies in mice harboring tissue-specific gain/loss of function mutations in clock genes revealed that the circadian clock acts on multiple pathways to control adipogenesis, lipogenesis/lipolysis and thermogenesis. Time-restricted eating (TRE), aligning feeding with the active period to restore clock function, represents a promising strategy to curb obesity. While TRE has shown clear benefits, especially in participants at higher cardiometabolic risk, current studies are limited in size and duration. Larger, well-controlled studies are warranted to conclusively assess the effects of TRE in relation to the metabolic status and gender. Field studies in shift-workers, comparing permanent night shift versus rotating shifts, are also necessary to identify the optimal time window for TRE.

An Intermittent Fasting Intervention for Black Adults Can Be Feasibly Implemented in Black Churches: A Cluster Randomized Controlled Pilot Study

BACKGROUND

Intensive lifestyle interventions, including modest reductions in daily caloric intake (ie, continuous calorie energy reduction [CER]), are recommended by US national professional health organizations (eg, American Heart Association). However, they are less effective in Black communities. A burgeoning literature has reported the promise of intermittent fasting (IF) as an alternative strategy for weight loss. However, IF studies have been conducted with White participants predominately and provided participant resources not readily available in real-world situations.

OBJECTIVE

Weight-loss and weight-related outcomes of a scalable (ie, able to be widely disseminated and implemented) IF intervention developed with and for Black adults were compared with a CER intervention for the purpose of determining IF's feasibility (ie, initial effectiveness, adherence, and acceptance) in a Black community.

DESIGN

A cluster randomized controlled pilot study was conducted.

PARTICIPANTS/SETTING

A total of 42 Black adults with a body mass index (calculated as kg / m2) ≥25 were recruited from 5 Black churches (3 IF and 2 CER) in Western New York State from September 2021 to May 2022. Participants were free of medical conditions that might have contraindicated participation in a weight-reduction program and other factors that might affect weight loss.

INTERVENTIONS

Community health workers delivered the 6-month, 16-session, faith-based IF and CER interventions.

MAIN OUTCOME MEASURES

The primary outcome was feasibility, consisting of initial effectiveness on body weight (ie, percent body weight lost from baseline to 6-month follow-up), adherence, and acceptability.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics and linear mixed models accounting for within-church clustering were used. A baseline covariate corresponding to the outcome variable was included in the model. Intent-to-treat analysis was used.

RESULTS

There was statistically significant weight loss within both arms (IF: -3.5 kg; 95% CI -6 to -0.9 kg, CER: -2.9 kg; 95% CI -5.1 to -0.8 kg) from baseline to 6-month follow-up. Compared with CER, IF led to significantly lower daily energy intake (414.2 kcal; 95% CI 55.2 to 773.2 kcal) and fat intake (16.1 g; 95% CI 2.4 to 29.8 g). IF may result in lower fruit and vegetable intake (-103.2 g; 95% CI -200.9 to -5.5 g) and fiber intake -5.4 g; 95% CI -8.7 to -2 g) compared with CER. Participants in the IF arm completed a mean (SE) of 3.8 (1.4) more self-monitoring booklets compared with those in the CER arm (P = .02). Participants reported high levels of satisfaction with the program.

CONCLUSIONS

An IF intervention developed with and for Black adults can be feasibly implemented in Black churches. Larger studies need to be conducted to ascertain the extent IF can serve as a viable weight-loss alternative to CER interventions in Black communities.

The metabolic and circadian signatures of gestational diabetes in the postpartum period characterised using multiple wearable devices

AIMS/HYPOTHESIS

Gestational diabetes mellitus (GDM) affects 14% of all pregnancies worldwide and is associated with cardiometabolic risk. We aimed to exploit high-resolution wearable device time-series data to create a fine-grained physiological characterisation of the postpartum GDM state in free-living conditions, including clinical variables, daily glucose dynamics, food and drink consumption, physical activity, sleep patterns and heart rate.

METHODS

In a prospective observational study, we employed continuous glucose monitors (CGMs), a smartphone food diary, triaxial accelerometers and heart rate and heart rate variability monitors over a 2 week period to compare women who had GDM in the previous pregnancy (GDM group) and women who had a pregnancy with normal glucose metabolism (non-GDM group) at 1-2 months after delivery (baseline) and 6 months later (follow-up). We integrated CGM data with ingestion events recorded with the smartphone app MyFoodRepo to quantify the rapidity of returning to preprandial glucose levels after meal consumption. We inferred the properties of the underlying 24 h rhythm in the baseline glucose. Aggregating the baseline and follow-up data in a linear mixed model, we quantified the relationships between glycaemic variables and wearable device-derived markers of circadian timing.

RESULTS

Compared with the non-GDM group (n=15), the GDM group (n=22, including five with prediabetes defined based on fasting plasma glucose [5.6-6.9 mmol/l (100-125 mg/dl)] and/or HbA1c [39-47 mmol/mol (5.7-6.4%)]) had a higher BMI, HbA1c and mean amplitude of glycaemic excursion at baseline (all p≤0.05). Integrating CGM data and ingestion events showed that the GDM group had a slower postprandial glucose decrease (p=0.01) despite having a lower proportion of carbohydrate intake, similar mean glucose levels and a reduced amplitude of the underlying glucose 24 h rhythm (p=0.005). Differences in CGM-derived variables persisted when the five women with prediabetes were removed from the comparison. Longitudinal analysis from baseline to follow-up showed a significant increase in fasting plasma glucose across both groups. The CGM-derived metrics showed no differences from baseline to follow-up. Late circadian timing (i.e. sleep midpoint, eating midpoint and peak time of heart rate) was correlated with higher fasting plasma glucose and reduced amplitudes of the underlying glucose 24 h rhythm (all p≤0.05).

CONCLUSIONS/INTERPRETATION

We reveal GDM-related postpartum differences in glucose variability and 24 h rhythms, even among women clinically considered to be normoglycaemic. Our results provide a rationale for future interventions aimed at improving glucose variability and encouraging earlier daily behavioural patterns to mitigate the long-term cardiometabolic risk of GDM.

TRIAL REGISTRATION

ClinicalTrials.gov no. NCT04642534.

Validation of a Smartphone Application for Monitoring Circadian Appetite: A Randomized Crossover Trial in Free-Living and Controlled Settings

BACKGROUND/OBJECTIVES

Appetite is affected by the circadian clock and exhibits diurnal variations. Nevertheless, accurately measuring subjective appetite throughout the day in a free-living setting poses a challenge. This study presents the validation of a novel smartphone application designed to capture, process and analyze circadian appetite fluctuations in a free-living setting.

METHODS

Twenty-four healthy participants (ages 38.34 ± 3.2 years) completed this randomized crossover study. Participants completed subjective appetite questionnaires every 30 min in a free-living environment, starting from waking hours until bedtime, using visual analog scale (VAS) via the pen and paper (PP) method and the new smartphone application (App). In addition, on two experimental days, separated by a week of washout, participants were provided either a high-energy breakfast (850 kcal) or a low-energy breakfast (250 kcal). Participants completed the appetite questionnaires using both methods every 30 min for 4 h, followed by an ad libitum lunch.

RESULTS

The high-energy breakfast led to significantly increased fullness sensation and decreased hunger, desire to eat, prospective consumption, and appetite score compared with the low-energy breakfast. There was no significant difference between the methods (PP and App) in all measured parameters under both the free-living environment and the controlled environment. Additionally, Bland-Altman analysis revealed a high degree of agreement between the PP and App methods. Moreover, most participants rated the App as the preferred method regardless of age.

CONCLUSIONS

Our findings show that the new smartphone application is a valid, reliable tool for measuring subjective appetite, suitable for use in chrononutritional studies conducted in a free-living environment and controlled settings.

Impact of Time-Restricted Eating and High-Intensity Exercise on Nutrient Intake in Women with Overweight/Obesity: Secondary Analysis of a Randomized Controlled Trial

BACKGROUND/OBJECTIVES

Inadequate micronutrient intakes are common in individuals with overweight/obesityand can exacerbate cardiovascular and metabolic disease risk. Diet and exercise are primary strategies for managing overweight and may influence nutrient intakes. In this secondary analysis of dietary data collected in a randomized controlled trial (RCT, ClinicalTrials.gov (NCT04019860), 15 June 2019) of time-restricted eating (TRE), high-intensity interval training (HIIT), a combination (TREHIIT), or a control group (CON), we investigated intervention effects on energy and nutrient intakes in women with overweight/obesity.

METHODS

We randomized 131 women (body mass index (BMI) ≥ 27 kg/m2) to 7 weeks of TRE (≤10-h daily eating window with ad libitum energy intake), HIIT (3 sessions/week, performed at ≥90% maximal heart rate), TREHIIT, or CON. Participants recorded all energy intake in an online food diary during a baseline week (week 0) and at the end of the study (week 6 and week 7). We investigated between-group differences in changes in mean energy, macronutrient, and micronutrient intakes.

RESULTS

TRE had reduced intakes of potassium, magnesium, and phosphorus compared with CON (p < 0.01). TREHIIT had non-significant reduced intakes of potassium, thiamine, magnesium, copper, and phosphorus (0.01< p < 0.05). HIIT alone did not negatively impact micronutrient intakes. TRE and TREHIIT induced suboptimal intakes for a greater number of micronutrients compared with HIIT and CON.

CONCLUSIONS

A ≤10-h TRE window might increase the risk of micronutrient inadequacy in women with overweight/obesity. Future research is needed to investigate the effects of integrating nutritional guidelines with TRE interventions to mitigate the risk of micronutrient inadequacy in individuals with overweight/obesity.

A Randomized Pilot Study of Time-Restricted Eating Shows Minimal Microbiome Changes

OBJECTIVE

TRE is an emerging approach in obesity treatment, yet there is limited data on how it influences gut microbiome composition in humans. Our objective was to characterize the gut microbiome of human participants before and after a TRE intervention. This is a secondary analysis of a previously published clinical trial examining the effects of time-restricted eating (TRE).

METHODS

In a previously published, 12-week randomized controlled trial, Chow et al. evaluated the effects of an 8-h TRE intervention on body composition in human participants. Chow et al. demonstrated significant reductions in weight, lean mass, and visceral fat in the TRE group compared to those following time-unrestricted eating (non-TRE). Stool samples were collected by a subset of those participants using home kits at both baseline and post-intervention for shotgun metagenomic sequencing for this secondary analysis. Microbiome community composition was compared before and after intervention as alpha and beta diversity.

RESULTS

Sixteen participants provided stool samples (eight in the TRE group and eight in the non-TRE group). Stool samples were collected from all participants at at least one time point, but both pre- and post-treatment samples were available from only five participants who completed both baseline and post-treatment collections. In alignment with the findings of Chow et al., the participants in the TRE group of the secondary analysis who collected microbiome sample(s) successfully reduced their eating window from an average of 15.3 ± 0.8 h at baseline to 9.3 ± 1.7 h during the intervention (mean ± SD, p < 0.001) and the non-TRE group's eating window remained unchanged. While the TRE group lost weight and visceral fat mass, no effect of the TRE intervention was observed on alpha diversity (Shannon index, Simpson index, and number of taxa, linear mixed models), beta diversity (Bray-Curtis, PERMANOVA), even after controlling for weight and visceral fat changes.

CONCLUSIONS

Our analysis did not detect any significant differences in gut microbiome composition or diversity indices between participants undergoing a TRE intervention and those in the control group. The study's findings are limited by a small sample size, short duration, and the collection of stool samples at only two time points. Future studies with larger sample sizes, longer durations, and more frequent sampling, and collection of detailed dietary data are needed to better understand the relationship between TRE and gut microbiome dynamics.

Gut microbiota and eating behaviour in circadian syndrome

Eating behaviour and circadian rhythms are closely related. The type, timing, and quantity of food consumed, and host circadian rhythms, directly influence the intestinal microbiota, which in turn impacts host circadian rhythms and regulates food intake beyond homeostatic eating. This Opinion discusses the impact of food intake and circadian disruptions induced by an obesogenic environment on gut-brain axis signalling. We also explore potential mechanisms underlying the effects of altered gut microbiota on food intake behaviour and circadian rhythmicity. Understanding the crosstalk between gut microbiota, circadian rhythms, and unhealthy eating behaviour is crucial to addressing the obesity epidemic, which remains one of the biggest societal challenges of our time.

The intertwined relationship between circadian dysfunction and Parkinson's disease

Neurodegenerative disorders represent a leading cause of disability among the elderly population, and Parkinson's disease (PD) is the second most prevalent. Emerging evidence suggests a frequent co-occurrence of circadian disruption and PD. However, the nature of this relationship remains unclear: is circadian disruption a cause, consequence, or a parallel feature of the disease that shares the same root cause? This review seeks to address this question by highlighting and discussing clinical evidence and findings from experiments using vertebrate and invertebrate animal models. While research on causality is still in its early stages, the available data suggest reciprocal interactions between PD progression and circadian disruption.

Intermittent fasting as a treatment for obesity in young people: a scoping review

Intermittent fasting focuses on the timing of eating rather than diet quality or energy intake, with evidence supporting its effects on weight loss and improvements in cardiometabolic outcomes in adults with obesity. However, there is limited evidence for its feasibility and efficacy in young people. To address this, a scoping review was conducted to examine intermittent fasting regimens in individuals aged 10 to 25 for the treatment of obesity focusing on methodology, intervention parameters, outcomes, adherence, feasibility, and efficacy. Due to the paucity of evidence in this age group, to adequately assess feasibility and adherence, all published studies of intermittent fasting in this age category, regardless of weight status and treatment intention, were included in the review. The review included 34 studies (28 interventional studies and 6 observational studies) with 893 participants aged 12 to 25. Interventions varied with 9 studies in cohorts with obesity utilizing intermittent fasting as an obesity treatment. Thirteen studies utilized 8-h time-restricted eating. Primary outcomes included cardiometabolic risk factors (7/28), anthropometric measurements (7/28), body composition (5/28), muscular performance (4/28), feasibility (1/28), and others (4/28). All 9 studies conducted in young people with obesity reported some degree of weight loss, although the comparator groups varied significantly. This review underscores the various utilizations of intermittent fasting in this age group and highlights its potential in treating obesity. However, the findings emphasize the need for rigorous studies with standardized frameworks for feasibility to ensure comparability and determine intermittent fasting's practicality in this age group depending on the treatment outcome of interest.

Time-restricted eating to address persistent cancer-related fatigue among cancer survivors: A randomized controlled trial

Purpose

Time-restricted eating (TRE) helps regulate rest-activity rhythms, blood glucose, and other diurnally regulated energetics processes, which may have implications for persistent fatigue. In a randomized controlled trial, we tested the effects of TRE vs. control on fatigue in cancer survivorship.

Methods

Adult cancer survivors were recruited who were 2 months to 2 years post-treatment and reported moderate to severe fatigue. Participants were randomized 1:1, TRE:control and all received individualized nutrition counseling. The TRE group self-selected a 10-hour eating window for 12 weeks. At baseline, week 6, and week 12, participants were asked to log eating instances, complete the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire (FACIT-F, higher score=less fatigue), and wear an actigraph and continuous glucose monitor.

Results

Thirty participants completed baseline assessments and were randomized (77% female, 53% Black/African American, 43% White, 7% Hispanic; 54.1±14.7 years old; 87% with blood cancer); 25 completed 12-week assessments. TRE led to a meaningful reduction in fatigue at week 12 controlling for baseline levels (change in FACIT-F fatigue subscale=0.0±5.4 for control, 4.1±5.7 for TRE, p=0.11, effect size [ES]=0.70; clinically meaningful threshold=3.0 points). Glucose parameters (e.g., average interstitial glucose, average fasting glucose) tended to be lower and rest-activity rhythms tended to indicate more regularity for those in the TRE vs. control group at weeks 6 and 12, though differences were not statistically significant (p>0.19).

Conclusions

A 12-week, nutritionist-led TRE program led to less fatigue than control. Continued study of TRE patterns are warranted to optimize this eating pattern and address persistent cancer-related fatigue.

Long-term effect of eating duration on all-cause mortality under different energy intake and physical activity levels

The long-term impact of eating duration on the risk of all-cause mortality remains unclear, with limited exploration of how different levels of energy intake and physical activity might influence this impact. To investigate, 24 484 American adults from the National Health and Nutrition Examination Survey spanning 1999-2018 were included. Eating duration was assessed via 24-h dietary recall, and all-cause mortality data were sourced from the National Death Index. The relationship between eating duration and all-cause mortality was analysed using Cox proportional hazards regression models, restricted cubic splines and stratification analysis with complex weighted designs. The median (IQR) of eating duration for participants was 12·5 (11·0, 14·0) h. In this study, 2896 death events were observed, and the median follow-up time (IQR) was 125 (77, 177) months. After multivariable adjustment, compared with Q1, Q2, Q3 and Q4 had reduced risks of all-cause mortality by 17, 15 and 13 %, respectively. Furthermore, each additional hour of eating duration was correlated with a 2 % decrease in the risk of all-cause mortality. Additionally, a non-linear dose-response relationship was observed between eating duration and the risk of all-cause mortality, showing a U-shaped relationship from 8·9 h to 15·3 h (P for non-linearity < 0·05). Interestingly, the non-linear dose-response relationship was observed exclusively among individuals with high energy intake or a lightly active physical activity level. These findings suggest potential health benefits from adjusting eating duration, though further prospective studies are needed for validation.

Effects of Intermittent Fasting on Female Reproductive Function: A Review of Animal and Human Studies

PURPOSE OF REVIEW

Intermittent fasting has gained significant attention, yet a comprehensive understanding of its impact on female reproductive health is lacking. This review aims to fill this gap by examining various intermittent fasting regimens and their effects on female reproductive function, along with potential mechanisms.

RECENT FINDINGS

In healthy non-overweight/obese or pregnant animal models, alternate-day fasting (ADF) and an 8-h time-restricted feeding (TRF) window may have adverse effects on reproductive function. However, these regimens show potential to mitigate negative consequences induced by a high-fat diet (HFD) or environmental exposure. A 10-h TRF demonstrates benefits in improving fertility in both normal-weight and HFD-fed animal models. In women with overweight/obesity or polycystic ovary syndrome (PCOS), the 5:2 diet and TRF significantly reduce the free androgen index while elevating sex hormone binding globulin, promising improvements in menstrual regulation. For pregnant Muslim women, available data do not strongly indicate adverse effects of Ramadan fasting on preterm delivery, but potential downsides to maternal weight gain, neonatal birthweight, and long-term offspring health need consideration. Factors linking intermittent fasting to female reproductive health include the circadian clock, gut microbiota, metabolic regulators, and modifiable lifestyles. Drawing definitive conclusions remains challenging in this evolving area. Nonetheless, our findings underscore the potential utility of intermittent fasting regimens as a therapeutic approach for addressing menstruation irregularities and infertility in women with obesity and PCOS. On the other hand, pregnant women should remain cognizant of potential risks associated with intermittent fasting practices.

Food Records Show Daily Variation in Diet during Pregnancy: Results from the Temporal Research in Eating, Nutrition, and Diet during Pregnancy Study

BACKGROUND

Diet is critical for pregnant individuals and their offspring, but insight into diet during pregnancy mainly comes from questionnaires and recalls.

OBJECTIVES

To obtain detailed real-time dietary data during pregnancy to evaluate intra- and interindividual variation in intakes.

METHODS

Pregnant individuals were recruited from a New York City health system December 2020-June 2023. Participants collected dietary intakes for 14 d (mean gestational weeks = 17.6) and again roughly 4 wk later (mean gestational weeks = 24.5). Participants logged each eating occasion using a smartphone and study-developed app, and wore a smartwatch capturing physiologic data.

RESULTS

In total, 150 individuals completed ≥1 data collection round, with 134 completing both rounds. Mean daily eating window was 10.82 h, with weekends having a significantly shorter window than weekdays (P < 0.001). Eating window was correlated with energy intake (r = 0.401, P < 0.001), driven by later last eating occasions. There was high intraindividual variation in macro- and micronutrient intakes [intraclass correlation coefficient (ICC), range 0.11-0.40] and food type (ICC range: 0.08-0.34), and differences between weekdays and weekends (less protein and micronutrients on weekends). Few participants' mean intakes met daily recommended dietary allowances for key micronutrients (under 15% for iron, magnesium, vitamin D, and vitamin E; under 30% for calcium, folate, zinc, and vitamin A).

CONCLUSIONS

Dietary intakes varied substantially within and between individuals, and mean nutrient intake estimates did not capture nutrient adequacy for individuals or populations. Future work that examines individual daily dietary intakes throughout pregnancy among diverse populations is needed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

The association of 24-hour behavior rhythms with stroke among American adults with prediabetes/diabetes: evidence from NHANES 2011-2014

BACKGROUND

Emerging evidence suggests that circadian rhythms play a role in the regulation of cardiovascular diseases (CVDs). We aim to examine the relationship between the 24-hour behavior rhythms (activity-rest and feeding-fasting rhythms) and stroke.

METHODS

The study included 3201 adult participants with prediabetes/diabetes from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. The 24-hour behavior rhythm indices were calculated using data from accelerometer wearable device and dietary recall for two nonconsecutive days. Six indices were calculated including interdaily stability (IS), intradaily variability (IV), relative amplitude (RA), average activity during the least active continuous 5-hour period (L5), Average activity during the most active continuous 10-hour period (M10) which reflects the activity-rest rhythm, and feeding rhythm score which reflects the feeding-fasting rhythm. These continuous variables were divided into quintiles for logistic regression models.

RESULTS

Comparing participants in quintile 1, those in quintile 5 of IS and RA exhibited a lower odds of stroke. Conversely, participants in quintile 5 of IV, L5, and L5 start time demonstrated a higher odds of stroke. Furthermore, participants in quintile 5 of feeding rhythm score had a significantly lower odds of stroke. The associations of IV and feeding rhythm score with stroke were more pronounced in participants with diabetes compared to those with prediabetes/diabetes. No significant associations were observed between other 24-hour behavior rhythms and stroke.

CONCLUSIONS

Overall, this study highlights a significant association between 24-hour behavior rhythm and stroke in American adults with prediabetes/diabetes.

Effects of healthy low-carbohydrate diet and time-restricted eating on weight and gut microbiome in adults with overweight or obesity: Feeding RCT

The effect of a healthy low-carbohydrate diet (HLCD) and time-restricted eating (TRE), alone or in combination, on body weight and gut microbiome beyond caloric restriction remains unclear. In this 12-week two-by-two factorial randomized trial with a 28-week follow-up among 96 participants with overweight or obesity, isocaloric-restricted feeding yields significant weight loss, ranging from 2.57 to 4.11 kg across different groups. Beyond caloric restriction, HLCD and TRE lead to additional reduction in body mass index. HLCD results in additional fat mass loss while TRE yields more lean mass loss. Additionally, HLCD leads to decreased fecal branched-chain amino acids, and TRE tends to yield an increased abundance of probiotic species involved in synthesizing short-chain fatty acids. Moreover, the effect of HLCD on reducing fat mass is sustained during the post-intervention follow-up. Overall, HLCD and TRE are effective in weight management and yield profound gut microbiome and metabolome alteration beyond caloric restriction. This study was registered at ChiCTR.org.cn (ChiCTR2200056363).