Rhythm Of Food Intake Research Articles

Dietary protein load affects the energy and nitrogen balance requiring liver glutamate dehydrogenase to maintain physical activity

Provision of amino acids to the liver is instrumental for gluconeogenesis while it requires safe disposal of the amino group. The mitochondrial enzyme glutamate dehydrogenase (GDH) is central for hepatic ammonia detoxification by deaminating excessive amino acids towards ureagenesis and preventing hyperammonemia. The present study investigated the early adaptive responses to changes in dietary protein intake in control mice and liver-specific GDH knockout mice (Hep-Glud1-/-). Mice were fed chow diets with a wide coverage of protein contents; i.e. suboptimal 10%, standard 20%, over optimal 30%, and high 45% protein diets; switched every 4 days. Metabolic adaptations of the mice were assessed in calorimetric chambers before tissue collection and analyses. Hep-Glud1-/- mice exhibited impaired alanine induced gluconeogenesis and constitutive hyperammonemia. The expression and activity of GDH in liver lysates were not significantly changed by the different diets. However, applying an in situ redox-sensitive assay on cryopreserved tissue sections revealed higher hepatic GDH activity in mice fed the high-protein diets. On the same section series, immunohistochemistry provided corresponding mapping of the GDH expression. Cosinor analysis from calorimetric chambers showed that the circadian rhythm of food intake and energy expenditure was altered in Hep-Glud1-/- mice. In control mice, energy expenditure shifted from carbohydrate to amino acid oxidation when diet was switched to high protein content. This shift was impaired in Hep-Glud1-/- mice and consequently the spontaneous physical activity was markedly reduced in GDH knockout mice. These data highlight the central role of liver GDH in the energy balance adaptation to dietary proteins.

Feasibility and Cardiometabolic Effects of Time-Restricted Eating in Patients with Metabolic Syndrome.

Metabolic syndrome (MetS) and a prolonged daily eating window (EW) are associated with circadian rhythm disruption and increased cardiometabolic risk. Misalignment between circadian timing system and daily rhythms of food intake adversely impacts metabolic regulatory mechanisms and cardiovascular function. Restricting the daily EW by imposing an eating-fasting cycle through time-restricted eating (TRE) can restore robust circadian rhythms, support cellular metabolism, and improve cardiometabolic health. The aim of this study was to assess a feasibility of 12-week TRE intervention with self-selected 10 h EW and effects of TRE on EW duration, cardiometabolic outcomes, daily rhythms of behavior, and wellbeing in Polish patients with MetS and EW ≥ 14 h/day. Dietary intake was monitored with a validated myCircadianClock application (mCC app). Adherence to TRE defined as the proportion of days recorded with mCC app in which participants satisfied 10-h TRE was the primary outcome. A total of 26 patients (aged 45 ± 13 years, 62% women, 3.3 ± 0.5 MetS criteria, EW 14 ± 1.5 h/day) were enrolled. Coexistence of increased waist circumference (WC) (96% of patients), elevated fasting plasma glucose (FPG) (77%), and elevated blood pressure (BP) (69%) was the most common MetS pattern (50%). TRE intervention (mean duration of 81.6 ± 12.6 days) led to reducing daily EW by 28% (p < 0.0001). Adherence to TRE was 87 ± 13%. Adherence to logging food intake on mCC app during TRE was 70 ± 27%. Post TRE, a decrease in body weight (2%, 1.7 ± 3.6 kg, p = 0.026), body mass index (BMI) (1%, 0.5 ± 1.2 kg/m2, p = 0.027), WC (2%, 2.5 ± 3.9 cm, p = 0.003), systolic BP (4%, 4.8 ± 9.0 mmHg, p = 0.012), FPG (4%, 3.8 ± 6.9 mg/dL, p = 0.037), glycated hemoglobin (4%, 0.2 ± 0.4%, p = 0.011), mean fasting glucose level from continuous glucose monitor (CGM) (4%, 4.0 ± 6.1 mg/dL, p = 0.002), and sleepiness score (25%, 1.9 ± 3.2 points, p = 0043) were observed. A significant decrease in body weight (2%), BMI (2%), WC (3%), mean CGM fasting glucose (6%), sleepiness score (27%), and depression score (60%) was found in patients with mean post-TRE EW ≤ 10 h/day (58% of total), and not in patients with EW > 10 h/day. Adherence to TRE was higher in patients with post-TRE EW ≤ 10 h/day vs. patients with EW > 10 h/day (94 ± 6% vs. 77 ± 14%, p = 0.003). Our findings indicate that 10-h TRE was feasible in the European MetS population. TRE resulted in reducing daily EW and improved cardiometabolic outcomes and wellbeing in patients with MetS and prolonged EW. Use of the mCC app can aid in implementing TRE. This pilot clinical trial provides exploratory data that are a basis for a large-scale randomized controlled trial to determine the efficacy and sustainability of TRE for reducing cardiometabolic risks in MetS populations. Further research is needed to investigate the mechanisms of TRE effects, including its impact on circadian rhythm disruption.

PS-B07-11: EFFECT OF TRF INTERVENTION ON DIET INDUCED OBESITY: A NON-PHARMACOLOGICAL THERAPEUTIC STRATEGY

Objectives: Time-restricted feeding (TRF) regulates the circadian rhythm of food intake that protects against metabolic disorders. The aim of our study are 12 hours time restricted feeding effects on diet induces obesity in rats model. Material &amp; Method: Total 21 Wistar rats were included i.e. control, TRF and High Fat diet (HFD) group. HFD group was fed with fatty diet at ad lib for two months and shifted to TRF (12 hours feeding i.e 8:00pm - 8:00am) for three months, after which they were again put back on ad lib. TRF group fed chow diet during 8:00pm to 8:00am for three months and then these rats shifted to ad lib for three months. Control group fed chow diet at ad lib. Body weight was calculated and blood samples were collected to measure blood glucose, insulin, lipid profile and gene expression. Results: The body weight of HFD group were significantly increased and TRF with chow diet were significantly decreased as compared to control rats (p = 0.0263) and (p = 0.0054) respectively. The level of HDL was reduced in rats fed with HFD whereas total cholesterol, TG and LDL were increased. TRF intervention with HFD diet reduced body weight, blood glucose level, TG and LDL and elevated the level of insulin, total cholesterol and HDL. Per1 and Bmal1 gene were up regulated in HFD group and after TRF intervention had reduced mRNA expression. TRF intervention with HFD and chow diet showed its legacy effect when put on ad lib. Conclusion: TRF intervention is easily adaptable lifestyle modification and non-pharmacological strategy can reduces the risk factor of obesity and its associated metabolic disorders.

Correction: An adipokine feedback regulating diurnal food intake rhythms in mice

Correction: An adipokine feedback regulating diurnal food intake rhythms in mice

High-Fat-Diet-Evoked Disruption of the Rat Dorsomedial Hypothalamic Clock Can Be Prevented by Restricted Nighttime Feeding

Obesity is a growing health problem for modern society; therefore, it has become extremely important to study not only its negative implications but also its developmental mechanism. Its links to disrupted circadian rhythmicity are indisputable but are still not well studied on the cellular level. Circadian food intake and metabolism are controlled by a set of brain structures referred to as the food-entrainable oscillator, among which the dorsomedial hypothalamus (DMH) seems to be especially heavily affected by diet-induced obesity. In this study, we evaluated the effects of a short-term high-fat diet (HFD) on the physiology of the male rat DMH, with special attention to its day/night changes. Using immunofluorescence and electrophysiology we found that both cFos immunoreactivity and electrical activity rhythms become disrupted after as few as 4 weeks of HFD consumption, so before the onset of excessive weight gain. This indicates that the DMH impairment is a possible factor in obesity development. The DMH cellular activity under an HFD became increased during the non-active daytime, which coincides with a disrupted rhythm in food intake. In order to explore the relationship between them, a separate group of rats underwent time-restricted feeding with access to food only during the nighttime. Such an approach completely abolished the disruptive effects of the HFD on the DMH clock, confirming its dependence on the feeding schedule of the animal. The presented data highlight the importance of a temporally regulated feeding pattern on the physiology of the hypothalamic center for food intake and metabolism regulation, and propose time-restricted feeding as a possible prevention of the circadian dysregulation observed under an HFD.

Time restricted feeding modifies leukocyte responsiveness and improves inflammation outcome.

Time restricted eating, the dietary approach limiting food intake to a maximal 10-hour period of daytime is considered beneficial in metabolic dysfunctions, such as obesity and diabetes. Rhythm of food intake and parallel changes in serum nutrient levels are also important entrainment signals for the circadian clock, particularly in tissues involved in metabolic regulation. As both the metabolic state and the circadian clock have large impact on immune functions, we investigated in mice whether time restricted feeding (TRF) affects systemic inflammatory potential. TRF slackened the symptoms in K/BxN serum-transfer arthritis, an experimental model of human autoimmune joint inflammation. Compared to ad libitum conditions TRF reduced the expression of inflammatory mediators in visceral adipose tissue, an integrator and coordinator of metabolic and inflammatory processes. Furthermore, TRF strengthened the oscillation of peripheral leukocyte counts and alongside decreased the pool of both marginated and tissue leukocytes. Our data suggest that the altered leukocyte distribution in TRF mice is related to the attenuated expression of adhesion molecules on the surface of neutrophils and monocytes. We propose that TRF modifies both rhythm and inflammatory potential of leukocytes which contribute to the milder reactivity of the immune system and therefore time-restricted eating could serve as an effective complementary tool in the therapy of autoinflammatory processes.

Role of sympathetic pathway in light-phase time-restricted feeding-induced blood pressure circadian rhythm alteration.

Disruption of blood pressure (BP) circadian rhythm, independent of hypertension, is emerging as an index for future target organ damage and is associated with a higher risk of cardiovascular events. Previous studies showed that changing food availability time alters BP rhythm in several mammalian species. However, the underlying mechanisms remain largely unknown. To address this, the current study specifically investigates (1) the relationship between rhythms of food intake and BP in wild-type mice; (2) effects of light-phase time-restricted feeding (TRF, food only available during light-phase) on BP circadian rhythm in wild-type and diabetic db/db mice; (3) the roles of the autonomic system and clock gene in light-phase TRF induced changes in BP circadian rhythm. Food intake and BP of C57BL/6J and db/db mice were simultaneously and continuously recorded using BioDAQ and telemetry systems under ad libitum or light-phase TRF. Per2 protein daily oscillation was recorded in vivo by IVIS spectrum in mPer2Luc mice. Autonomic nerve activity was evaluated by heart rate variability, baroreflex, urinary norepinephrine (NE) and epinephrine (Epi) excretion, and mRNA expressions of catecholamines biosynthetic and catabolic enzymes, and alpha-adrenergic receptors in mesenteric resistance arteries. We found that in wild-type mice, the BP level was correlated with the food intake temporally across the 24 h. Reversing the feeding time by imposing light-phase TRF resulted in reverse or inverted BP dipping. Interestingly, the net changes in food intake were correlated with the net alteration in BP temporally under light-phase TRF. In db/db mice, light-phase TRF worsened the existing non-dipping BP. The food intake and BP circadian rhythm changes were associated with alterations in Per2 protein daily oscillation and the time-of-day variations in heart rate variability, baroreflex, and urinary excretion of NE and Epi, and increased mRNA expression of Slc6a2 (encoding NE transporter) and Adra1d (encoding alpha-adrenergic receptor 1d) in the mesenteric resistance arteries, indicating the sympathetic nervous system (SNS) was modulated after light-phase TRF. Collectively, our results demonstrated that light-phase TRF results in reverse dipping of BP in wild-type and diabetic db/db mice and revealed the potential role of the sympathetic pathway in light-phase TRF-induced BP circadian rhythm alteration.

Time-restricted eating as a novel strategy for treatment of obesity and it's comorbid conditions

The article provides a review of the current literature about time-restricted eating (TRE) as a new tool for the treatment of obesity and comorbid conditions. The search for new nutritional strategies in obesity, one of which is TRE, is due to the weak adherence of patients to hypocaloric diets in the long term, as well as the available data on the importance of -desynchronization of food intake with natural circadian rhythms in the development and progression of obesity and cardio--metabolic complications. The article describes the main mechanisms that regulate the circadian rhythms of food intake and nutrient absorption, substantiates the importance of adhering to a physiological diet for maintaining metabolic health. The main part of the review is devoted to reviewing the currently available researches on the effectiveness of various strategies of intermittent energy restriction for weight loss and the correction of metabolic parameters. Potential mechanisms of the -effect of TRE on health are discussed, including those mediated by an unintentional decrease in caloric intake and changes in eating behavior, and differences in the effectiveness of early and late TRE. The article contains a detailed discussion of the potential problems and contradictions associated with the use of time-restricted eating in clinical practice, namely: the limitations and inconsistencies of the available clinical trials, the lack of data on long-term efficacy and safety, social and psychological limitations that impede the widespread use of TRE.

0226 Circadian influence on food intake among adolescents with overweight and healthy weight

Abstract Introduction Meal timing has been linked to obesity in adults and children; however, evidence for an endogenous influence of the circadian system on food intake is unknown. We measured food intake during forced desynchrony (FD) in adolescents with healthy weight (HW) or overweight (OW), hypothesizing that circadian timing would affect food intake independent of the environmental cycle and that the food intake rhythm would be delayed in adolescents with OW compared to HW. Methods Participants were 51 (29m) adolescents (12-15yr); 24 were HW and 27 OW determined by CDC norms. Participants completed seven, 28h-FD cycles; 6 meals occurred at fixed times each cycle with foods selected ~1h before meals and weighed before and after. Each meal’s energy intake was computed relative to total energy consumed in that FD cycle. Endogenous circadian period was determined using salivary dim-light melatonin onset (DLMO) phases (DLMO=0°). Time awake effect was assessed using mixed effect models and circadian phase with multilevel cosinor that included time awake as a categorical covariate. Results Circadian period was not significantly different between OW and HW (mean, StDev; HW =24.19h,0.22; OW=24.22h,0.14). Overall, participants consumed more calories on the cycles’ first meals (22.0% [21.3;22.6]) compared to the last meal (12.4% [11.8;13.0]). Adolescents with OW vs. HW consumed a higher proportion of calories later in the wake episode (F(5,2081)=2.63,p=.02). As hypothesized, circadian phase influenced caloric intake with an amplitude of 2.66% [2.19;3.14] percent daily calories and an acrophase of 301°[291;310], equivalent to ~17:52 in this population. The circadian influence differed by weight category (likelihood ratio test of both amplitude and acrophase; χ2(2)=10.7,p&amp;lt;.01), with those with OW showing a lower amplitude (OW = 2.11%[1.40;2.82], HW=3.53%[2.94;4.12] and later acrophase (OW=301° [287;314], HW=290° [278;302]). Conclusion Results show for the first time an independent influence of the endogenous circadian timing system on caloric intake of humans that differed as a function of body weight: caloric intake for adolescents with OW had a circadian rhythm with blunted amplitude and delayed peak phase. These observations show circadian control of food intake that may be stronger in HW than OW adolescents. Support (If Any) P20GM139743; R01DK101046; R01HL153969

Regulation of ILC3/Th17-Mediated Intestinal Immune Response by Circadian Rhythm

The circadian rhythm is a widely-recognized phenomenon, according to which the life activities of organisms change periodically, synchronizing with the day and night cycles. The activities of the immune system are also regulated by the circadian rhythm. Group 3 innate lymphoid cells (ILC3s) and T helper 17 (Th17) cells (ILC3/Th17) are the innate and adaptive subsets of immune cells mediating type 17 immune response, which is featured by the expression of transcription factor retinoid orphan receptor gamma t (RORγt) and the production of interleukin (IL)-17 and IL-22. The processes of type 17 immune response are completed mainly through the participation of ILC3/Th17 and are closely associated with the intestinal immune response. Recent studies have found that the immune response mediated by ILC3/Th17 is intricately regulated by the circadian rhythm through molecular mechanisms controlling the circadian rhythm, or through other external factors that change according to the light-darkness cycle, for example the food intake rhythm. The secretion of cytokines changes along with the regulatory effect of circadian rhythm on ILC3/Th17, which in turn impacts, to a certain degree, on the onset and development of intestinal inflammatory diseases, including bacterial infection and autoimmune diseases. The understanding of mechanisms regulating ILC3/Th17 responses by the circadian rhythm may promote better understanding of the course of action of the immune system and facilitate the development and discovery of potential targets for treatment of intestinal inflammatory diseases.

Computational Approaches and Tools as Applied to the Study of Rhythms and Chaos in Biology.

The temporal dynamics in biological systems displays a wide range of behaviors, from periodic oscillations, as in rhythms, bursts, long-range (fractal) correlations, chaotic dynamics up to brown and white noise. Herein, we propose a comprehensive analytical strategy for identifying, representing, and analyzing biological time series, focusing on two strongly linked dynamics: periodic (oscillatory) rhythms and chaos. Understanding the underlying temporal dynamics of a system is of fundamental importance; however, it presents methodological challenges due to intrinsic characteristics, among them the presence of noise or trends, and distinct dynamics at different time scales given by molecular, dcellular, organ, and organism levels of organization. For example, in locomotion circadian and ultradian rhythms coexist with fractal dynamics at faster time scales. We propose and describe the use of a combined approach employing different analytical methodologies to synergize their strengths and mitigate their weaknesses. Specifically, we describe advantages and caveats to consider for applying probability distribution, autocorrelation analysis, phase space reconstruction, Lyapunov exponent estimation as well as different analyses such as harmonic, namely, power spectrum; continuous wavelet transforms; synchrosqueezing transform; and wavelet coherence. Computational harmonic analysis is proposed as an analytical framework for using different types of wavelet analyses. We show that when the correct wavelet analysis is applied, the complexity in the statistical properties, including temporal scales, present in time series of signals, can be unveiled and modeled. Our chapter showcase two specific examples where an in-depth analysis of rhythms and chaos is performed: (1) locomotor and food intake rhythms over a 42-day period of mice subjected to different feeding regimes; and (2) chaotic calcium dynamics in a computational model of mitochondrial function.

Time-Restricted Eating and Metabolic Syndrome: Current Status and Future Perspectives.

Metabolic syndrome (MetS) occurs in ~30% of adults and is associated with increased risk of cardiovascular disease and diabetes mellitus. MetS reflects the clustering of individual cardiometabolic risk factors including central obesity, elevated fasting plasma glucose, dyslipidemia, and elevated blood pressure. Erratic eating patterns such as eating over a prolonged period per day and irregular meal timing are common in patients with MetS. Misalignment between daily rhythms of food intake and circadian timing system can contribute to circadian rhythm disruption which results in abnormal metabolic regulation and adversely impacts cardiometabolic health. Novel approaches which aim at restoring robust circadian rhythms through modification of timing and duration of daily eating represent a promising strategy for patients with MetS. Restricting eating period during a day (time-restricted eating, TRE) can aid in mitigating circadian disruption and improving cardiometabolic outcomes. Previous pilot TRE study of patients with MetS showed the feasibility of TRE and improvements in body weight and fat, abdominal obesity, atherogenic lipids, and blood pressure, which were observed despite no overt attempt to change diet quantity and quality or physical activity. The present article aims at giving an overview of TRE human studies of individuals with MetS or its components, summarizing current clinical evidence for improving cardiometabolic health through TRE intervention in these populations, and presenting future perspectives for an implementation of TRE to treat and prevent MetS. Previous TRE trials laid the groundwork and indicate a need for further clinical research including large-scale controlled trials to determine TRE efficacy for reducing long-term cardiometabolic risk, providing tools for sustained lifestyle changes and, ultimately, improving overall health in individuals with MetS.

Natural food intake patterns have little synchronizing effect on peripheral circadian clocks

BackgroundCircadian rhythms across mammalian tissues are coordinated by a master clock in the suprachiasmatic nucleus (SCN) that is principally entrained by light-dark cycles. Prior investigations have shown, however, that time-restricted feeding (TRF)—daily alternation of fasting and food availability—synchronizes peripheral clocks independent of the light-dark cycle and of the SCN. This has led to the idea that downstream peripheral clocks are entrained indirectly by food intake rhythms. However, TRF is not a normal eating pattern, and it imposes non-physiologic long fasts that rodents do not typically experience. Therefore, we tested whether normal feeding patterns can phase-shift or entrain peripheral tissues by measuring circadian rhythms of the liver, kidney, and submandibular gland in mPer2Luc mice under different food schedules.ResultsWe employed home cage feeders to first measure ad libitum food intake and then to dispense 20-mg pellets on a schedule mimicking that pattern. In both conditions, PER2::LUC bioluminescence peaked during the night as expected. Surprisingly, shifting the scheduled feeding by 12 h advanced peripheral clocks by only 0–3 h, much less than predicted from TRF protocols. To isolate the effects of feeding from the light-dark cycle, clock phase was then measured in mice acclimated to scheduled feeding over the course of 3 months in constant darkness. In these conditions, peripheral clock phases were better predicted by the rest-activity cycle than by the food schedule, contrary to expectation based on TRF studies. At the end of both experiments, mice were exposed to a modified TRF with food provided in eight equally sized meals over 12 h. In the light-dark cycle, this advanced the phase of the liver and kidney, though less so than in TRF with ad libitum access; in darkness, this entrained the liver and kidney but had little effect on the submandibular gland or the rest-activity cycle.ConclusionsThese data suggest that natural feeding patterns can only weakly affect circadian clocks. Instead, in normally feeding mice, the central pacemaker in the brain may set the phase of peripheral organs via pathways that are independent of feeding behavior.

An adipokine feedback regulating diurnal food intake rhythms in mice.

Endogenous circadian clocks have evolved to anticipate 24 hr rhythms in environmental demands. Recent studies suggest that circadian rhythm disruption is a major risk factor for the development of metabolic disorders in humans. Conversely, alterations in energy state can disrupt circadian rhythms of behavior and physiology, creating a vicious circle of metabolic dysfunction. How peripheral energy state affects diurnal food intake, however, is still poorly understood. We here show that the adipokine adiponectin (ADIPOQ) regulates diurnal feeding rhythms through clocks in energy regulatory centers of the mediobasal hypothalamus (MBH). Adipoq-deficient mice show increased rest phase food intake associated with disrupted transcript rhythms of clock and appetite-regulating genes in the MBH. ADIPOQ regulates MBH clocks via AdipoR1-mediated upregulation of the core clock gene Bmal1. BMAL1, in turn, controls expression of orexigenic neuropeptide expression in the MBH. Together, these data reveal a systemic metabolic circuit to regulate central circadian clocks and energy intake.

High-throughput discovery of genetic determinants of circadian misalignment.

Circadian systems provide a fitness advantage to organisms by allowing them to adapt to daily changes of environmental cues, such as light/dark cycles. The molecular mechanism underlying the circadian clock has been well characterized. However, how internal circadian clocks are entrained with regular daily light/dark cycles remains unclear. By collecting and analyzing indirect calorimetry (IC) data from more than 2000 wild-type mice available from the International Mouse Phenotyping Consortium (IMPC), we show that the onset time and peak phase of activity and food intake rhythms are reliable parameters for screening defects of circadian misalignment. We developed a machine learning algorithm to quantify these two parameters in our misalignment screen (SyncScreener) with existing datasets and used it to screen 750 mutant mouse lines from five IMPC phenotyping centres. Mutants of five genes (Slc7a11, Rhbdl1, Spop, Ctc1 and Oxtr) were found to be associated with altered patterns of activity or food intake. By further studying the Slc7a11tm1a/tm1a mice, we confirmed its advanced activity phase phenotype in response to a simulated jetlag and skeleton photoperiod stimuli. Disruption of Slc7a11 affected the intercellular communication in the suprachiasmatic nucleus, suggesting a defect in synchronization of clock neurons. Our study has established a systematic phenotype analysis approach that can be used to uncover the mechanism of circadian entrainment in mice.

Adaptation of the night eating questionnaire for Brazilian adolescents.

IntroductionNight Eating Syndrome (NES) is characterized by a delay in the circadian rhythm of food intake and affects 1.5% of the general population, occurring more frequently in obese people. The Night Eating Questionnaire (NEQ) was originally developed for the American adult population. It is a self-administered instrument widely used in the identification and follow-up of individuals with NES. Although the NEQ has been translated and validated for Brazilian adults, there are no reports of its adaptation for use in Brazilian adolescents. The present study aimed to adapt and evaluate reliability and reproducibility of the NEQ for Brazilian adolescents.Material and MethodsInitially, a semantic adaptation of the Portuguese version of the NEQ was performed by 3 professionals with experience with adolescents. The suggested text was analyzed and consolidated item by item by the researchers and then presented to 21 adolescents from an intermediate school in Fortaleza. The questions with low level of understanding (<90%) were modified and the questionnaire was re-applied to 23 adolescents, obtaining satisfactory understanding.ResultsThe version of the NEQ for Brazilian adolescents, compared to the adult version, contains changes in items 3, 5, 6, 7 and 13. The questionnaire was administered to 463 students aged 11 to 17 years (mean ± SD = 13.7 ± 1.2), from 3 schools. The internal consistency, measured by the Cronbach's alpha coefficient, was 0.73. The reproducibility that was measured after one week in 27 adolescents was 0.92 (95% CI 0.82-0.96).ConclusionThe new version of the NEQ for Brazilian adolescents presents excellent reproducibility and good internal consistency and is a simple and useful instrument to evaluate nocturnal eating symptoms in this age group.

Daily rhythms in food intake and locomotor activity in a colony of domestic cats

BackgroundDaily rhythms have been widely investigated in various mammals but, surprisingly, literature is scarce and conflicting regarding the domestic cat, Felis catus. This may come from the difficulty to analyse rhythms in a species showing high interindividual variability and from the common idea that the rhythms of the cat are rather random. To elucidate the subject, two groups of indoor cats (14 in total) living in a cattery room, were followed on a 24 h/7 day basis, using advanced telemetry technologies, i.e. passive RFID, automated weighing of electronic scales and UWB technology with accuracy ensuring a good reliability of the results.ResultsWhile covering on average 1.74 ± 0.4 km and eating 46.4 ± 3.6 g (≈ 179 kcal) of dry food per day, findings indicate 24 h periodicity in the locomotor and feeding rhythms of the cats. Systematically, their locomotor behaviour was more rhythmic than their eating behaviour (p < 0.01), possibly reflecting the flexibility of the eating patterns of the cat initially enabling it to adapt to daily rhythms of its prey. In their daily patterns, the indoor individuals showed two main troughs of activity and food intake—in the middle of the day and in the middle of the night—and two main peaks: one in the morning (especially before sunrise and food renewal), the other in the evening (following the end of the work day of the animal staff and before sunset), supporting previous work demonstrating peaks at dusk and dawn and confirming the crepuscular nature of the species. No general pattern emerged according to a more nocturnal versus diurnal organisation.ConclusionsBimodality, more than chronotypes, seems therefore to best characterise the activity and feeding rhythms of the species as it was demonstrated in the individuals among the different categorisations. By validating the use of new tracking technologies as well as of adapted chronobiological parameters to assess the daily rhythm of cats living indoors, this study opens the way for more adequate analyses of cat behaviour through time under various conditions.

Rhythmic Food Intake Drives Rhythmic Gene Expression More Potently than the Hepatic Circadian Clock in Mice

Every mammalian tissue exhibits daily rhythms in gene expression to control the activation of tissue-specific processes at the most appropriate time of the day. Much of this rhythmic expression is thought to be driven cell autonomously by molecular circadian clocks present throughout the body. By manipulating the daily rhythm of food intake in the mouse, we here show that more than 70% of the cycling mouse liver transcriptome loses rhythmicity under arrhythmic feeding. Remarkably, core clock genes are not among the 70% of genes losing rhythmic expression, and their expression continues to exhibit normal oscillations in arrhythmically fed mice. Manipulation of rhythmic food intake also altersthe timing of key signaling and metabolic pathways without altering the hepatic clock oscillations. Our findings thus demonstrate that systemic signals driven by rhythmic food intake significantly contribute to driving rhythms in liver gene expression and metabolic functions independently of the cell-autonomous hepatic clock.

Chrono-Nutrition: The Relationship between Time-of-Day Energy and Macronutrient Intake and Children's Body Weight Status.

The time of eating has been considered to have an important role in weight regulation. However, it is unknown if there are specific daily patterns of energy and macronutrient distribution that could be more beneficial for metabolic outcomes, especially obesity. This study aimed to assess the effect of time-of-day energy and macronutrient intake at 4 y of age on the weight status at 7 y of age. The study sample included 1961 children from the population-based birth cohort Generation XXI, with data on 3-day food diaries at 4 y and body mass index (BMI) z-scores at 7 y. Dietary patterns based on the collected data were obtained for the distribution of energy and macronutrients across eating occasions. Having a relatively higher energy intake at lunch and supper (OR = 1.19, 95% CI = 1.05 to 1.34) or at mid-afternoon (OR = 1.18, 95% CI = 1.05 to 1.34) at 4 y was associated with higher odds of becoming overweight/obese at 7 y. A relatively higher intake of fat at lunch was positively associated with later children's odds for being overweight or obese (OR = 1.17, 95% CI = 1.03 to 1.32). These associations were independent of the effect on children's eating behaviors related to appetite. Our results also show a detrimental relation between skipping breakfast and eating late in the day and children's body weight. Considering all daily eating occasions, a higher proportion of energy and macronutrient intake at the main meals and a lower proportion during the afternoon and evening seems to be more beneficial for children's weight. These results emphasize the important role of daily food intake rhythm on excessive weight gain in childhood.

Spinal Cord Injury in Rats Dysregulates Diurnal Rhythms of Fecal Output and Liver Metabolic Indicators.

Spinal cord injury (SCI) dysregulates metabolic homeostasis. Metabolic homeostasis is optimized across the day by the circadian system. Despite the prevalence of metabolic pathologies after SCI, post-SCI circadian regulation of metabolism remains understudied. Here, we hypothesized that SCI in rats would disrupt circadian regulation of key metabolic organs, leading to metabolic dysregulation. Female and male Sprague-Dawley rats received moderate thoracic (T)-9 contusion SCI (or sham surgery). First, SCI disrupted diurnal rhythms in two metabolic behaviors: fecal production and food intake rhythms were ablated acutely. SCI also expedited whole-gut transit time. In parallel, acute SCI increased plasma glucose. Diurnal glucose storage-release cycles regulated by the liver were disrupted by SCI, which also increased liver glucose metabolism messenger RNAs (mRNAs). Further, SCI disrupted liver clock gene expression and suppressed inflammatory gene rhythms. Together, our novel data suggest that SCI disrupts typical metabolic and circadian function. Improving post-SCI metabolic function could enhance recovery of homeostasis.