Feeding Window Research Articles

Effects of Religious Fasting on Markers of Oxidative Status in Vitamin D-Deficient and Overweight Orthodox Nuns versus Implementation of Time-Restricted Eating in Lay Women from Central and Northern Greece

Background/Objectives: The Mediterranean diet has been widely suggested to exert significant beneficial effects on endothelial oxidative status and cardiometabolic health. Greek Orthodox monasteries, due to their specific nutritional and sartorial habits, comprise a population thatstrictly adheres to nutritional patterns with restricted eating and a plant-based subset of the Mediterranean diet, often accompanied by profound hypovitaminosis D. Time-restricted eating (TRE) is also adopted bya large part of the general lay Greek population for health-promoting reasons, without restrictions on animal product consumption, as imposed by Orthodox religious fasting. However, the comparative effects of these nutritional patterns on oxidative stress markers remain scarce. Methods: The present study attempted to evaluate the effects of Christian Orthodox fasting (COF) in a group of vitamin D-deficient and overweight Orthodox nuns from Central and Northern Greece compared to the implementation of TRE, a 16:8 dietary regimen (16 h of food abstinence and 8 h of feeding) in a cohort of adult women from the general population from the same region with regard to markers of endothelial oxidative status. A group of 50 women from two Orthodox monasteries in Northern Greece and one group of 50 healthy lay women were included. During the enrollment, a detailed recording of their dietary habits was performed, along with a scientific registry of their demographic and anthropometric characteristics (via bioimpedance). The Orthodox nuns followed a typical Orthodox fasting regimen [daily feeding window (8 a.m.–4 p.m.)], whereas the lay women followed a TRE 16:8 regimen with the same feeding time-window with a recommendation to follow a low-fat diet, without characteristics of the Mediterranean diet. We included a complete biochemical analysis, as well as calciotropic profiles [calcium—Ca, albumin, parathyroid hormone—PTH, and 25-hydroxyvitamin D—25(OH)D] and markers of TAC (total antioxidant capacity), GSH (glutathione),and thiobarbituric acid reactive substances (TBARSs) concentrations as markers of oxidative status. Results: All the groups were compared at the baseline regarding their calcium, PTH, and 25(OH)D concentrations, with no statistically significant differences between the groups apart from higher PTH levels in the nuns due to lower 25(OH)D levels. The Orthodox nuns manifested a lower median GSH compared to the controls (6.0 vs. 7.2, p 0.04) and a higher median TAC (0.92 vs. 0.77, p < 0.001). The TBARS comparisons showed no significant difference between the two groups. No significant associations of oxidative status with 25(OH)D, PTH, and the markers of glucose homeostasis were evident. Conclusions: The results of this small pilot study indicate that both dietary regimens have advantages over the oxidative markers compared to each other, with increased TAC in the group of Orthodox nuns after a 16-week period of COF compared to a 16:8 TRE and increased GSH concentrations in the lay women group. Future randomized trials are required to investigate the superiority or non-inferiority between these dietary patterns in the daily clinical setting.

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

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. 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.

The acute effect of time-restricted feeding (12 & 16 h) and varying exercise intensities on fat-oxidation rate in inactive young adults – a randomized control trial

Background and purposeTime-restricted feeding (TRF) is a dietary pattern that alternates between periods of fasting and feeding, which has gained significant attention in recent years. The 16/8 approach consists of fasting for 16 h and feeding for an 8-h window, while the 12/12 method consists of fasting for 12 h and a 12-h feeding window. Limited research exists comparing the effects of these methods coupled with physical activity (PA). The aim of this investigation was to examine the acute effects between conditions of varying TRF durations (12 and 16 h) and PA intensities on the fat oxidation rate (FOR). It was hypothesized that i) the TRF16 conditions would exhibit higher FORmax and that PA would enhance these effects, and ii) High Intensity Interval Training (HIIT) would result in greater effects on FORmax compared to Low-Moderate Intensity Steady State Continuous Training (MICT) PA.Methods and resultsEighteen young adults (age: 23 ± 2.0 yrs., body mass index: 23.5 ± 2.8 kg·m−2) were recruited and participated in the supervised intervention. The discrete component open circuit spirometry system was used to measure oxygen consumption (VO2), and Frayne’s equation was used to determine the FOR plus FORmax. ANOVA was used to determine pre/post-intervention differences in FORmax. The FORmax for the TRF16 + HIIT intervention was significantly higher than the TRF12 (mean difference = 0.099 g·min-1, p = 0.011, 95% CI 0.017 to 0.180) and TRF16 fast alone (mean difference = 0.093 g·min-1, p = 0.002, 95% CI 0.027 to 0.159). The FORmax for TRF12 + HIIT intervention was significantly higher than the TRF12 fast alone (mean difference = 0.070 g·min−1, p = 0.023, 95% CI 0.007 to 0.134). The TRF16 + HIIT intervention was also significantly higher than the TRF12 fast alone (mean difference = 0.099 g·min−1, p = 0.011, 95% CI 0.017 to 0.180).ConclusionThis study contributes to the ever-growing body of literature on the acute effects of TRF and PA on young adult males and females. The findings suggest that the TRF16 + HIIT PA intervention results in the highest FORmax. Trial registrationRetrospective Registration ISRCTN # 10076373 (October 6, 2023).

Time-Restricted Feeding Protects against Renal Ischemia-Reperfusion Injury in Mice.

Ischemia-reperfusion injury (IRI) in the kidneys is a major cause of acute kidney injury (AKI). Time-restricted feeding (TRF), known for its metabolic health benefits and alleviation of various chronic diseases without calorie restriction, was investigated for its potential protective effects against IRI-induced AKI. Male C57BL/6 mice underwent unilateral IRI, with their kidneys collected after two days. For two weeks before IRI induction, the TRF group had unlimited access to standard chow but within an 8-hour feeding window during the dark cycle. The study groups were Control, TRF, IRI, and TRF + IRI. In the TRF + IRI group, tubular damage scores significantly decreased compared to the IRI group. Furthermore, the TRF + IRI mice had lower levels of phosphorylated NF-κB and fewer F4/80-positive macrophages than the IRI group. Oxidative stress markers for lipids and proteins were also notably lower in the TRF + IRI group. Additionally, TUNEL-positive tubular cells and cleaved caspase-3 expression were reduced in the TRF + IRI group. Without calorie restriction, TRF mitigated renal damage by reducing inflammation, oxidative stress, and tubular apoptosis in renal IRI. This suggests that TRF could be a promising dietary strategy to prevent IRI-induced AKI.

Reestablishment of ad libitum feeding following partial food deprivation: Impact on locomotor activity, visceral fat, food intake, and circadian glycemic curve

ABSTRACT Food deprivation has been associated with the development of metabolic pathologies. Few studies have explored the repercussions of a partial food deprivation following the reestablishment of an ad libitum diet. This study investigates the impact of a partial food deprivation (an 8-hour food intake restriction coupled with a 4-hour feeding window during the active phase) and the subsequent return to ad libitum feeding on the glycemic curve, food intake, and locomotor behavior. Wistar rats aged 45 days were subjected to 6 weeks of a partial food deprivation followed by 6 weeks of ad libitum feeding. Body weight, visceral fat, food intake, circadian glycemia, oral glucose tolerance, and locomotor activity were evaluated. It was found that the partial food deprivation resulted in the reduction of both the body weight and food intake; however, it increased visceral fat by 60%. Circadian glycemic values were altered at all intervals during the light phase, and glucose sensitivity improved at 60 minutes in the oral glucose tolerance test (OGTT). In the food-deprived group, the locomotor activity rhythm was reduced, with an observed delay in the peak of activity, reduction in total activity, and a decrease in the rhythmicity percentage. After the reestablishment of the ad libitum feeding, there was recovery of body weight, no difference in visceral fat, normalization of the food intake pattern, circadian glycemia, and oral glucose tolerance. Additionally, the return to ad libitum feeding restored locomotor activity, although the duration required for its complete recovery warrants further investigation. In conclusion, partial food deprivation induces physio-metabolic changes in rats, most of which are reversed after reestablishing ad libitum feeding.

Time-restricted feeding protects against cisplatin-induced acute kidney injury in mice.

Time-restricted feeding (TRF), devoid of calorie restriction, is acknowledged for promoting metabolic health and mitigating various chronic metabolic diseases. While TRF exhibits widespread benefits across multiple tissues, there is limited exploration into its impact on kidney function. In this study, our aim was to investigate the potential ameliorative effects of TRF on kidney damage in a mouse model of cisplatin-induced acute kidney injury (AKI). Cisplatin-induced AKI was induced through intraperitoneal injection of cisplatin into C57BL/6 male mice. Mice undergoing TRF were provided unrestricted access to standard chow daily but were confined to an 8-hour feeding window during the dark cycle for 2 weeks before cisplatin injection. The mice were categorized into four groups: control, TRF, cisplatin, and TRF + cisplatin. The tubular damage score and serum creatinine levels were significantly lower in the TRF + cisplatin group compared to the cisplatin group. The TRF + cisplatin group exhibited reduced expression of phosphorylated nuclear factor kappa B, inflammatory cytokines, and F4/80-positive macrophages compared to the cisplatin group. Furthermore, oxidative stress markers for DNA, protein, and lipid were markedly decreased in the TRF + cisplatin group compared to the cisplatin group. TUNEL-positive tubular cells, cleaved caspase-3 expression, and the Bax/Bcl-2 ratio in the TRF + cisplatin group were lower than those in the cisplatin group. TRF, without calorie restriction, effectively mitigated kidney damage by suppressing inflammatory reactions, oxidative stress, and tubular apoptosis in a mouse model of cisplatin-induced AKI. TRF holds promise as a novel dietary intervention for preventing cisplatin-induced AKI.

Exploring the therapeutic potential of plasma from intermittent fasting and untreated rats on aging-induced liver damage.

This research aims to investigate the effects of plasma from 12-month-old intermittently fasting rats (IFpls) and untreated rats (Npls) on the liver biomolecules and histological changes in 24-month-old male Sprague-Dawley rats. Fasting rats underwent an 18-h daily fasting period and a 6-h feeding window for 35 days. The plasma was administered bi-daily, and blood samples were examined for specific liver biomolecules. Fourier transform infrared (FTIR) spectroscopy and linear discriminant analysis (LDA) was used to identify molecular profiles. Liver sections were stained for histopathological evaluation, and the expression levels of Notch signalling pathway components were assessed. Distinct molecular profiles were identified across liver biomolecules, lipids, proteins and nucleic acids with high accuracy. Notably, IFpls was found to protect against hepatic instability, microvesicular steatosis and liver fibrosis by decreasing lymphatic infiltration density and Notch pathway expression levels. Both treatments reduced protein oxidation and carbonylation, with Npls showing a pronounced decrease in protein oxidation. Furthermore, Npls increased protein conformation and glycogen/phosphate content, while IFpls increased glucose/protein content. Both IFpls and Npls induce substantial and unique alterations in liver biomolecules. IFpls offers a protective effect on various liver conditions, while Npls exhibits promising results in reducing protein oxidation and altering biomolecule content. These findings offer valuable insights for future research and potential therapeutic approaches.

Effects of Early and Late Time-Restricted Feeding on Parameters of Metabolic Health: An Explorative Literature Assessment.

Chrono-nutrition (meal timing) aligns food consumption with one's circadian rhythm. The first meal (e.g., breakfast) likely promotes synchronization of peripheral circadian clocks, thereby supporting metabolic health. Time-restricted feeding (TRF) has been shown to reduce body weight (BW) and/or improve cardiovascular biomarkers. In this explorative literature assessment, 13 TRF randomized controlled trials (RCTs) were selected from PubMed and Scopus to evaluate the effects of early (eTRF: first meal before 10:30 a.m.) and late TRF (lTRF: first meal after 11:30 a.m.) on parameters of metabolic health. Although distinct variations in study design were evident between reports, TRF consistently decreased energy intake (EI) and BW, and improved insulin resistance as well as systolic blood pressure. eTRF seemed to have a greater beneficial effect than lTRF on insulin resistance (HOMA-IR). Importantly, most studies did not appear to consider chronotype in their evaluation, which may have underestimated TRF effects. TRF intervention may be a promising approach for risk reduction of human metabolic diseases. To conclusively determine benefits of TRF and identify clear differences between eTRF and lTRF, future studies should be longer-term (≥8 weeks) with well-defined (differences in) feeding windows, include participants chronotypically matching the intervention, and compare outcomes to those of control groups without any dietary limitations.

Temporal patterns of food consumption and their association with cardiovascular risk in rotating shift workers

ObjectiveWe aimed to evaluate the association of temporal patterns of food consumption with cardiovascular disease (CVD) risk. MethodsThis cross-sectional study included male rotating shift workers in an iron ore extraction company. Data on food consumption was collected using a 24-hour recall, applied by trained interviewers. The variables for temporal patterns of food consumption were: eating window, eating at night, number of meals and omission of breakfast. CVD-risk was measured by calculating the Framingham coronary heart disease risk score (FCRS), and classified as low risk or intermediate to high risk. Descriptive, univariate and multivariate logistic regression analyses examined the association between variables related to temporal patterns of food consumption and CVD-risk. ResultsThe study assessed 208 workers, the majority with 20 to 34 years (45.1%), non-white (77.2%), and 5 years or more in shift work (76.0%). Most participants had a feeding window exceeding 12 hours (63.9%), consumed meals until 10 p.m. (68.1%), had five or more meals per day (54.8%), and did not skip breakfast (86.5%). Regarding CVD-risk, 43.8% of the participants were classified with intermediate to high risk for CVD. In the multivariate model, a feeding window (OR: 2.32; 95%CI: 1.01-5.35), eating after 10 p.m. (OR: 3.31; 95%CI: 1.01-11.0), and skipping breakfast (OR: 2.58; 95%CI: 1.07-6.19) increased the likelihood of intermediate to high CVD-risk. Conversely, having five or more meals per day decreased the odds (OR: 0.27; 95%CI: 0.08-0.92). ConclusionEating window longer than 12 hours, eating after 10 p.m., less than four meals a day and omission of breakfast, are associated with cardiovascular risk in shift workers.

Spacing Analysis of Casting Dolly Windows for Tunnel Sidewall Lining Based on the Flow Characteristics of Freshly Mixed Concrete.

During the actual construction of tunnel sidewall lining, construction workers often use only one or two windows per layer for pouring in order to reduce the construction sequence, which often leads to a reduction in the quality of tunnel sidewall concrete pouring. Therefore, this study analysed the necessity of the window-by-window pouring of sidewall lining through the study of concrete flow characteristics of the tunnel sidewall lining pouring process, and the reasonable spacing of pouring windows was analysed. This study firstly verified the accuracy of the simulation parameters and the feasibility of the simulation method of the lining pouring process through indoor experiments and simulation analyses, and then it numerically simulated and analysed the flow of concrete during the lining pouring process of tunnel sidewalls. The following conclusions were made: the smaller the slump of the freshly mixed concrete, the higher the pumping flow rate; additionally, the shorter the one-time pouring distance, the smaller the spacing of the trolley feeding window should be. Furthermore, this study makes suggestions for the reasonable spacing of pouring trolleys under several working conditions.

The impact of dietary and sleep rhythms on blood pressure in children and adolescents: a cross-sectional study.

Evidence about the relationship between meal and sleep time and CVD in children is scarce. The aims of this study were to describe the association between life rhythm patterns and blood pressure in children. This research was conducted among 5,608 children aged 6 to 15 years old in Chongqing and Sichuan provinces in 2021 and 2022. Dietary and sleep rhythms information was collected. The time of the first meal and last meal, and sleep time, were obtained. The mean age was 10.48 ± 2.24 years old, with 2958 (52.75%) male participants. The mean feeding window on weekdays was 11.69 h, 12.42 h, and 13.23 h for participants aged 6-7 years old, 8-12 years old and 13-15 years old, respectively. Weekday feeding window and last mealtime were positively correlated with blood pressure levels. And the changes in the feeding window between weekdays and weekends were significantly correlated with BP. Sleep duration and change in wake time were significantly correlated with SBP. Based on these results, this study identified the optimal combination of dietary and sleep rhythm interventions for children younger than 12 years of age and aged 12 and older, respectively. Disorder dietary and sleep rhythms disorders may correlate with elevated blood pressure levels, suggesting developing optimal dietary and sleep rhythm patterns could prevent the incidence of CVDs in children. The optimal dietary rhythm was defined by the indexes of breakfast time, dinner time and daily feeding window. As good meal patterns are defined as satisfied the following three items: for children younger than 12 years should have breakfast after 7:30 am; aged 12 years and over should have breakfast after 7 am; having dinner before 6 pm; daily feeding window less than 12.5 h. And less optimal dietary rhythm should satisfy any condition or eat dinner between 6 pm and 8 pm; and poor dietary rhythm should not satisfy any of the three criteria and eat dinner after 8 pm. Children with optimal dietary rhythm (in group A) had lower SBP (P < 0.001), DBP (P = 0.002) and MAP (P < 0.001) than those in group C.

The modulation of carbohydrate intake and intermittent fasting in obese Saudi women: a pilot study

BackgroundIn recent years, the prevalence of overweight and obesity has increased, leading to the development of various dietary interventions as potential treatments. Two popular diets are time-restricted feeding and low-carbohydrate diets, but there is limited research on the effects of combining them. This study assessed the effects of pairing an eight-hour time-restricted feeding window with a moderate-carbohydrate diet and compared to a paired eight-hour time-restricted feeding window with a regular diet.ResultsThe study involved 52 obese women divided into three groups: the first group followed an 8 h time-restricted feeding with a moderate low-carbohydrate diet (8-hTRF+mLCD), the second group followed an 8 h time-restricted feeding with a regular diet (8-hTRF), and the third group was the control group. Both 8 h TRF+mLCD and 8 h TRF groups had a decrease in TG levels compared to the control group. The HDL levels in both TRF groups were significantly higher than the control group, while LDL levels remained statistically insignificant in both TRF groups.ConclusionsThis suggests that an 8 h TRF with or without mLCD can effectively treat obesity without a change in physical activity, and combining it with a low-carbohydrate diet gives better and more rapid results.

Prolonged fasting times reap greater geroprotective effects when combined with caloric restriction in adult female mice

Emerging new evidence highlights the importance of prolonged daily fasting periods for the health and survival benefits of calorie restriction (CR) and time-restricted feeding (TRF) in male mice; however, little is known about the impact of these feeding regimens in females. We placed 14-month-old female mice on five different dietary regimens, either CR or TRF with different feeding windows, and determined the effects of these regimens on physiological responses, progression of neoplasms and inflammatory diseases, serum metabolite levels, and lifespan. Compared with TRF feeding, CR elicited a robust systemic response, as it relates to energetics and healthspan metrics, a unique serum metabolomics signature in overnight fasted animals, and was associated with an increase in lifespan. These results indicate that daytime (rest-phase) feeding with prolonged fasting periods initiated late in life confer greater benefits when combined with imposed lower energy intake.

Time Restricted Eating may induce diabetes remission

Intermittent fasting diets, also known as Time Restricted Eating (TRE) have become popular in recent years as an effective weight loss method. TRE is a form of chrono nutrition that focuses on limiting calorie intake to a shortened “eating window”, followed by a prolonged fasting period (e.g. 8 hour feeding window, 16 hour fasting period). Initial time-restricted feeding studies on diet-induced obesity in mice demonstrated improved weight loss and metabolic parameters when eating duration was limited to 8 hours or less. TRE has since been investigated in humans with some evidence for effectiveness in reducing bodyweight and improving certain cardio-metabolic parameters. In this study, researchers conducted a 3-month TRE diet intervention among 36 people with diabetes and found almost 90% of participants, including those who took blood sugar-lowering agents and insulin, reduced their diabetes medication intake after TRE. Fifty-five percent of these people experienced diabetes remission, discontinued their diabetes medication and maintained it for at least one year. Importantly, sixty-five percent of the study participants who achieved diabetes remission had a diabetes duration of more than 6 years – disease duration >6 years was an exclusion criteria in the DIRECT study which reported diabetes remission following a Very Low calorie Diet programme. Overall this study provided preliminary evidence of efficacy of TRE for diabetes remission. It would be interesting to have a randomised controlled study of VLCD vs TRE with a primary outcome measure being rate of diabetes remission. The study was published in the Endocrine Reviews and received funding from the National Natural Science Foundation of China.

Geometric-kinematic model for reinforced concrete core drilling

Since diamond-impregnated tools have a big share on tools for construction, the development of more efficient ones is necessary in the near future. The drilling speed performance is one of the concerns during the development of new diamond-impregnated segments in concrete core drilling. However, observations only based on experiments can be very costly, considering a quite demanding amount of material and workforce. One of the solutions to overcome these issues is the development of a geometric-kinematic model (containing a kinematic process model, material model, and drilling force model) to simulate the tangential and normal forces of diamond-impregnated segments in core drilling process. Such model is regularly used in the literature for the simulation of a bonded-abrasives process. The main purpose of the geometric-kinematic model is to generate simulations for the concrete core drilling for the tool performance estimation. This allows an evaluation of the geometric characteristics’ (diamond morphology, orientation, size, and positioning) impact of diamond-impregnated segments and of drilling parameters on the drilling force. The geometric-kinematic model will use detailed segment descriptions with stochastic and deterministic variables. The drilling simulation delivers a consistent drilling forces prediction in Utliberg concrete and ASTM A615 steel at the frequently used core drilling feed window. Besides, the model shows the competence to evaluate the impact of a diamond layer characteristics (diamond size and number of rows), allowing the comparison of distinct diamond arrangements designs between each other.

Extended Inter-Meal Interval Negatively Impacted the Glycemic and Insulinemic Responses after Both Lunch and Dinner in Healthy Subjects.

This study aimed to investigate the glycemic and insulinemic effects of lunch timing based on a fixed feeding window, and the effects of apple preload on postprandial glucose and insulin responses after nutrient-balanced lunch and the subsequent high-fat dinner in healthy participants. Twenty-six participants completed four randomized, crossover experimental trials: (1) early standardized lunch at 12:00 (12S); (2) apple preload to 12S (12A+S); (3) late standardized lunch at 14:00 (14S); and (4) apple preload to 14S (14A+S); wherein twenty participants’ blood samples were collected for insulin analysis following the lunch trails. In each experimental trial, each participant equipped with a continuous glucose monitor (CGM) was provided with a standardized breakfast and a high-fat dinner to be consumed at 8:00 and 18:00, respectively. The late lunch (14S) resulted in significantly elevated glucose peak, delayed insulin peak time, decreased insulin sensitivity, and increased insulin resistance following the lunch; also decreased glycemic response following the subsequent dinner and larger blood glucose fluctuation over the 24-h period compared with the 12S. The 14A+S significantly reduced the glucose peak, the insulin peak time and the glycemic variability following the lunch, also the 24-h glycemic variability compared with the 14S. The insulin sensitivity was significantly improved in the 12A+S, compared with that of the 12S. In conclusion, the present study found that an extra 2-h inter-meal fasting before and after lunch resulted in elevated glycemic response in both macronutrient-balanced meal and high-fat meal in healthy subjects. The negative impact of a late lunch could be partly reversed by the apple preload, without a trade-off of insulin secretion.

Effect of live yeast supplementation and feeding frequency in male finishing pigs subjected to heat stress.

In growing pigs, reduced growth during heat stress (HS) is mainly related to decreased feed intake. The study aimed to determine whether the reported positive effects of live yeast (LY) supplementation in HS pigs were due to a modified feeding behaviour or energy metabolism, and if these can be replicated by imposing an increased meal frequency. The effect of LY supplementation [0 (NS) vs. 100 (LY) g/ton of feed], and of feeding window (FW) [unlimited or Unli, 2FW of 1 h each, and 8FW of 15 min each] were measured in entire male finishing pigs (n=36). Ambient temperature was at 22°C during the thermoneutral period (TN; 5 d) and at 28°C during the HS period (5 d). Heat exposure decreased dry matter intake (DMI) and retained energy (RE) (-627 and -460 kJ∙kg BW-0.60∙d-1, respectively; P<0.01). During HS, LY-supplementation in Unli pigs decreased inter-meal intervals (P=0.02) attenuating HS effect on DMI which tended to improve RE (P=0.09). NS-8FW had higher DMI and RE than NS-2FW (P<0.05) but protein deposition (PD) were similar. Supplemented pigs had higher PD during HS regardless of FW (+18 g∙d-1; P=0.03). Comparing the 2FW groups, improved heat tolerance of LY-supplemented pigs were due to improved insulin sensitivity (P<0.05) and latent heat loss capacity after a meal (P<0.05) allowing them to increase their DMI (via an increased number of meals) and thus their energy efficiency. Imposing an increased meal frequency improved DMI in HS pigs but did not replicate positive effects of LY on protein deposition.

Determinants and drivers of young children's diets in Latin America and the Caribbean: Findings from a regional analysis.

The Latin America and Caribbean region exhibit some of the lowest undernutrition rates globally. Yet, disparities exist between and within countries and countries in the region increasingly face other pressing nutritional concerns, including overweight, micronutrient deficiencies and inadequate child feeding practices. This paper reports findings from a regional analysis to identify the determinants and drivers of children's diets, with a focus on the complementary feeding window between the age of 6-23 months. The analysis consists of a narrative review and descriptive data analysis, complemented with qualitative interviews with key informants in four countries: Guatemala, Paraguay, Peru and Uruguay. Findings indicate that poverty and inequality (disparities within countries by wealth and residence), unequal access to services, inadequate coverage of social programmes and lack of awareness on appropriate feeding practices are important drivers for inadequate diets. We conclude that countries in the region need to invest in policies to tackle overweight and micronutrient deficiencies in young children, considering inequalities between and within countries, enhance coverage of social protection programmes, improve coordination between sectors to improve children's diets and expand the coverage and intensity of awareness campaigns on feeding practices, using iterative programme designs.

The Fasting and Shifted Timing (FAST) of Eating Study: A pilot feasibility randomized crossover intervention assessing the acceptability of three different fasting diet approaches

Background and aimsThe aim of this study is to assess the acceptability of following three different fasting protocols [Early Time-restricted Feeding (eTRF; eating majority of kcals before 5pm), Time-restricted Feeding (TRF; restricting feeding window to 8 h/d), or Alternate Day Fasting (ADF; complete fasting every other day)]. MethodsIn this remotely delivered six-week crossover intervention, participants were randomly assigned to follow either an eTRF, TRF, or ADF diet for one week, followed by a one-week washout period. Participants followed all three diets and completed questionnaires assessing self-reported weight, energy intake, dietary acceptability (Food Acceptability Questionnaire), and facilitators and barriers to adhering to each diet. Differences in main outcomes (e.g., dietary acceptability and weight loss) were assessed via repeated measures ANOVA. ResultsA total of 32 of participants began the study (mean BMI of 32.6 ± 6.0 kg/m2). There were no differences in kcals or weight loss among the three diets. Dietary acceptability was higher on the TRF diet (54.1 ± 8.2) than the eTRF (50.2 ± 6.6, p = 0.02) or ADF (48.0 ± 7.9, p = 0.004) diets. The majority of participants (71%) indicated the TRF diet was the easiest to follow and 75% said that ADF was the most difficult. Participants cited having a mobile app to track their diet and being provided with menu plans would help facilitate adherence with their diets. ConclusionsThis study found that acceptability was highest for an TRF diet and lowest for ADF, with no differences in weight loss or change in energy intake among the TRF, ADF, or eTRF groups. Clinical trials.gov identifierNCT04527952.

Abstract 2161: Fasting fueled ketogenesis inhibits ovarian cancer and promotes anti-tumor T cell response

Abstract Epithelial Ovarian Cancer (EOC) is the most lethal gynecologic cancer with no predominant genetic alteration identified that can be therapeutically targeted. Low-cost non-toxic approaches such as dietary modulations alter the responses of host and the cancer cells. Limited scientific investigations have examined the link between nutrition and EOC. Here, we tested the outcome of intermittent fasting (IF) on EOC progression with focus on fasting driven anti-tumor immune responses. Female C57/B6 mice were injected intraperitoneally with 5x106 mouse epithelial ovarian cancer ID8 (p53-/-, ID8 p53-/-, PTEN-/- and ID8 p53-/-, BRCA-/-) cells and fed either ad libitum (RD) or subjected to IF, where they underwent 16 hour fasting and 8 hour feeding window for 5 days/week. Tumor progression was monitored by ascites formation and abdominal circumference. Immune profiling was performed by flow cytometry using BD FACS Calibur. Untargeted metabolomics was performed in plasma from RD and IF mice using LC-MS/MS. Enhancement of immunotherapy was tested by combining IF with anti-PD 1 (100 µg/mice, every 5th day, 3 times) in ID8 p53-/- tumor bearing mice and similar parameters were examined. IF reduced the growth of ID8 (p53-/-, ID8 p53-/-, PTEN-/- and ID8 p53-/-, BRCA-/-) tumors, increased overall survival when compared to RD mice. IF promoted anti-tumor T cell response as seen by increase in CD4+ and CD8+ cells with enhanced expression of IFNγ, granzyme B and perforin compared to RD mice bearing ID8 cells in the ascites and blood. A striking observation was that the CD4+ T cells from IF mice exhibited a strong Th1 phenotype (CD4+IFNγ+), while Th2 phenotype (CD4+IL4+) was significantly decreased. IF when combined with anti-PD-1 treatment significantly improved survival and potentiated the T cell mediated anti-tumor response. Metabolic analysis revealed an enrichment in ketone body biosynthetic pathway as reflected by 5fold increase in serum ketone bodies such as beta hydroxy butyrate (BHB) and acetoacetate, when compared to RD. Receptors that have been reported to response to BHB as a ligand, specifically GPR109A and GPR41, were highly expressed on T cells derived from IF mice. BHB treatment enhanced the CD8+ T cell effector function as reflected by increased levels of IFNγ, granzyme B and perforin compared to untreated CD8+ T cells. Our study shows that IF significantly restricts EOC growth, improve survival, potentiate chemotherapy and immunotherapy anti-tumor response by augmenting T cell mediated anti-tumor immune responses. We also provide evidence that IF generated bioactive metabolite BHB which can be a potential substitute for availing the ant-tumor benefits of IF. Thus, our data provides strong evidence for IF and its metabolic mediator BHB for ameliorating EOC progression and as a viable approach in maintaining and sustaining an effective anti-tumor T cell response alone and in combination with immunotherapy. Citation Format: Mary Priyanka Udumula, Laila Poisson, Lin Chun-Hui, Nivedita Tiwari, Harshit Singh, Giri Shailendra, Ramandeep Rattan. Fasting fueled ketogenesis inhibits ovarian cancer and promotes anti-tumor T cell response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2161.