Whereas some individuals present a relatively stable state throughout the day i. For example, it includes a similar number of items formulated to assess morning and eveningness preferences, thus avoiding the morning-biased measurement characteristic of other instruments.
It also clearly identifies the assessment of multiple dimensions. Even though previous instruments have been proposed to assess multi-dimensions of chronotype e. The wording of the items of the MESSi is also more updated and the questions are simpler to respond and interpret. Finally, the inclusion of the Distinctness, a dimension with growing recognized relevance in the assessment of circadian rhythm Di Milia, ; Oginska, ; Dosseville et al.
Nevertheless, in comparison to other popular alternatives, the MESSi composed of 15 items adds a new dimension and still provides a shorter solution than the MEQ composed of 19 items ; as compared to the CSM which contains 13 items it only adds two items. In short, all studies have replicated the three-factor internal structure i.
However, the factor structure has not been challenged by comparing a one-, two- or three-factor structure.
In Sync with Adolescence
Rahafar et al. Furthermore, Rodrigues et al. Finally, though not explicitly testing for measurement invariance, Diaz-Morales et al. Therefore, testing factorial invariance is an important novel goal of this study. Concurrent validity of the MESSi has also been confirmed against other typical questionnaires. Regarding Distinctness, the correlation between its scores and the CSM and the rMEQ was negative but lower than with the other two subscales Randler et al.
Overall, these results suggest that Distinctness acts separately from Morning Affect and Eveningness. These authors also reported some preliminary evidence for the MESSi chronotype assessment using measures of actigraphy and of the sleep-wake rhythm. The literature on circadian preferences has also explored how these change throughout the development and if there are differences between sexes. This inconsistency mimics that obtained when other instruments are used to asses chronotype and may be a result of low sample size and high variation in age Randler, ; Adan et al.
Regarding the subscale of Distinctness, the results have been very regular across all of the just mentioned studies, with females reporting higher Distinctness than males e. The evaluation of chronotype in different age groups has revealed that children tend to be morning-oriented and then become more evening-oriented during adolescence e. Some of the studies that have used the MESSi have reported positive relations between Morning Affect and age and negative relations between Distinctness and age e.
Regarding the relation between Eveningness and age, the results have been more irregular, with some reporting negative relations e. Given the existing literature, the main aim of the current work was to test competing models for the factorial structure of the MESSi and the invariance across age classes and sex of the best fitting model. In other words, the current work aimed to test the originally proposed three-factor structure of the MESSi Morning Affect, Eveningness, and Distinctness against uni- and two-factor model solutions.
The first comparison helps to establish the multidimensionality purpose that underlined the development of this instrument Randler et al. The second evaluation aims to explore the idea that morningness-eveningness corresponds to a single dimension Di Milia and Randler, ; Diaz-Morales et al.
Furthermore, we aimed to establish that the best-fitting model would be invariant in relation to sex and age. This is an important statistical procedure in psychometric research to assure comparability across the groups being considered Schmitt and Ali, With the exception of the study by Rodrigues et al. Finally, we also explored the differences between sexes and among age groups in the scores of each subscale of the MESSi Morning Affect, Eveningness, and Distinctness.
Such division took into account some of the ages at which stronger changes in chronotype are expected to occur c. Introduction while also ensuring a reasonable number of participants per age group. The MESSi is a self-report instrument that includes 15 items from three other questionnaires.
The original items are from the Composite Scale of Morningness Smith et al. The total of the items is divided in three subscales, each one composed of five items: Morning Affect, Eveningness, and Distinctness. The items related to the Morning Affect subscale measure morningness preferences early schedules , whereas the items of the Eveningness subscale assess evening preferences late schedules.
The remaining five items constitute the Distinctness subscale, that is, the amplitude dimension of this instrument. Each item is responded using a 5-points Likert scale and scored with 1—5 points, although some of them are reverse coded. Data collection was done from In that same e-mail they were informed that it was a short questionnaire study about chronotype and partnership and that it would last about 15 min. They were also told that an anonymized procedure was in place, that their data would be used only for research purposes, and that they could withdraw their participation at any time without any consequences.
We also explicitly stated that it was a voluntary and unpaid study. The questions concerning the MESSi took approximately 5 min to complete. We did not control for double or triple access. Two participants were excluded from the sample due to being under 18 years of age. For the two-factor model, the scoring of the items from the Eveningness scale were reversed turning them into items contributing to a Morningness evaluation as if we were dealing with a morning-eveningness continuum rather than two separate subscales as initially intended. The fit of these models was judged based on the guidelines provided by Hair et al.
Only one of the tested models acceptably fitted the data see results section and so only its measurement invariance by sex and by age-groups was analyzed, based on a forward approach Dimitrov, Firstly, configural invariance was established if the model was found to fit well within each group under analyses. Then, metric invariance was investigated, meaning that the model that constraints all loadings to be equal across groups should be as good a fit as the model posing no equality constraints on the groups i.
Finally, scalar invariance was also tested, based on finding a non-expressive difference between the loading-constraint model and a model constraining all intercepts to be equal across groups i. Following the establishment of measurement invariance, a latent mean comparison approach was taken for between and among group comparisons i. These analyses were further complemented with effect sizes, descriptive data and a two between-factor ANOVA to control for the uneven distribution of men and women by age-groups.
In turn, CFA, measurement invariance, latent mean comparisons, between factor correlation analyses and correlation analyses between subscales and age were ran using Mplus v7. Hence, and because there were no missing values, the Robust Maximum Likelihood estimator was used for confirmatory factor analyses and for measurement analyses. Also, non-parametric tests were used for the correlation analyses. Table 1. Loading values were always significant and varied between 0.
Supplementary Material. Full measurement invariance by sex was established for the three-factor model given that it fitted well for female and male participants taken separately i. Table 1 1 , that forcing all item loadings to be equal between groups did not significantly worsened the fit of a non-constraint model i. Evidence for the three levels of measurement invariance by age-groups was also found, namely configural invariance c.
The direction of these results reflect those found for the same measures and groups when taking the sum of the responses of the set of items composing each measure c. Table 2 , also for the descriptive measures found using the complete sample. Table 2. Descriptive measures for the subscales of the MESSi and effect sizes for between-groups comparisons. The direction of these results, again, is in line with that found for the same measures and groups when taking the sum of the responses of the set of items composing each scale c.
Because men and women were not evenly distributed by age-groups, we conducted an ANOVA including both age-groups and sex as between groups factors. These results suggest that sex- and age-based differences on the MESSi seem to be independent of each other. The MESSi provides new way of assessing circadian preferences while introducing several improvements as compared to other existing instruments. Here, we tested the originally proposed three-factor structure of the MESSi Morning Affect, Eveningness, and Distinctness , against other possible factorial structures.
Also, we assessed the factor invariance across age groups and sex. The current study addressed these novel issues using a large sample of participants. Our results confirmed that the originally proposed three-factor structure of the instrument provides a better fit to the data as compared to the alternatives of a one- and two-factor structure. Some studies that have tested the concurrent validity of the MESSi against other instruments e.
However, our results suggest that each of the three different factors contribute separately to the assessment of chronotype. Empirically, studies have further started to show that each of these dimensions relate in a differential and significant manner with health-related measures as well as with some personality characteristics Diaz-Morales et al.
Furthermore, each scale obtained good internal consistency range 0. The correlations found among the subscales are in line with those reported in other studies. The correlation between Distinctness and Eveningness was also significant but with a low positive correlation coefficient; a similar result was reported by Rodrigues et al.
Establishing that the best-found model would be invariant for the variables of sex and age was also an important and novel goal of this work. Full measurement invariance of the three-factor model was obtained for these variables indicating that the MESSi can accurately reflect sex and age differences related to the constructs. Such results reassure researchers that the MESSi accurately grasps the constructs within sex- and age- diversified samples and is an appropriate instrument to compare the results between sexes and across age groups.
We also explored the differences between sexes and among age groups in the scores of each subscale of the MESSi. Even though our sample was composed of unequal groups per sex or age, the same results were obtained when using balanced-sized groups see footnotes 2 and 4. The pattern of differences between sexes has been quite inconsistent across studies, particularly with respect to the dimensions of Morning Affect and Eveningness, but we were able to find some communality with our data.
Specifically, our females scored lower than males on Eveningness and the difference was not significant for Morning Affect Diaz-Morales et al. On the other hand, the finding that females score higher on Distinctness than males has been more consistently reported e. Regarding age, our correlation results revealed that as participants get older, they tend to score lower on Eveningness and Distinctness and higher on Morning Affect. This last result is in agreement with the idea that after the end of adolescence, people tend to become more morning oriented Roenneberg et al.
On the other hand, the negative correlation between Eveningness and age has been replicated in some studies e. The negative correlation between age and Distinctness obtained in our sample has also been found in most validation studies of the MESSi in which this relation was analyzed e. Note that the disparate results regarding the correlations between age and Morning Affect and Eveningness are in favor of the idea that the latter two are indeed different constructs.
Finally, we found no significant interaction between age and sex, a result that differs from that reported by Diaz-Morales et al. As for the differences among the age groups, considering the scarceness of studies that have addressed them before, we refrain from discussing these data at this time. The diversity of results regarding the relation between age and the three subscales of this instrument could be due to a number of factors such as the different age ranges that have been tested across studies and the differential sample sizes.
Furthermore, there is a number of factors that seem to affect chronotype such as individual and environmental variables e. It is noteworthy, though, that some results have indeed been consistent such as finding that females score consistently higher on Distinctness than males and the negative correlation between age and Eveningness and Distinctness. Future studies should explore the factors likely underlying these consistencies and also those that might justify the discrepancies.
In sum, this study confirms that the best fitting model for our data include the three factors described in the original presentation of the MESSi: Morning Affect, Eveningness and Distinctness. We further demonstrated that such structure is invariant for the variables of sex and age which ensures researchers that all of the instrument can be reliably used to assess chronotype in males and females as well as in various age groups. We also provide additional information regarding the relation between these two variables and chronotype in our sample with contributes to a more global understanding of this variable across countries.
All authors contributed to the writing and discussion and approved the manuscript.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Adan, A. Circadian typology: a comprehensive review. Baehr, E. Individual differences in the phase and amplitude of the human circadian temperature rhythm: with an emphasis on morningness-eveningness.
Sleep Res. Brown, F. Consistent with the latter, Roenneberg et al. Hale and Do 67 similarly reported that factors such as noise, ambient light, and crowding within an urban environment may underlie some of the ethnic differences in sleep duration. Social schedules may also directly interfere with individual sleep preferences, subsequently affecting health Accordingly, in a sample of the general population in Switzerland and Germany, it was observed that individuals with an evening chronotype accumulate sleep debt during the work week, which they compensate for by sleeping longer on weekends By contrast, extreme morning types show a smaller shift in sleep times between work and free days, although they do accumulate sleep debt during weekends in an attempt to keep up with social norms These findings have been replicated in other populations and countries 68 , For instance, in a representative sample in Italy of adolescents aged 14—18 y, eveningness was associated with later bedtime and wake-up time especially on weekends , shorter time in bed during the week, longer time in bed at the weekend, irregular sleep-wake schedule, and more frequent napping during school days In another study involving adults aged 30—49 y from New Zealand, chronotype was assessed via the MEQ The sample was balanced in relation to the proportions of the population with a morning or evening chronotype Such studies suggest that factors including study or work schedules should be considered in epidemiologic studies investigating the relation between chronotype, diet, and health and trying to elucidate the causal pathways linking them.
It is not clear based on the currently available literature whether or not chronotype is a determinant causal factor of eating patterns or food intake or merely a reflection of a complex set of behaviors that also affect diet associated to diet owing to confounding factors. Furthermore, it may be that chronotype is a consequence of caused by the entraining effect of food constituents 16 or eating patterns on the peripheral clocks 15 Figure 1.
The literature on this topic is currently emerging and we are far from understanding the link between chronotype and diet. Tables 1 and 2 provide a summary of the characteristics and main findings of observational studies that have investigated the association between chronotype and dietary intake or eating behavior. Summary of characteristics of cross-sectional studies investigating the relation between chronotype and diet 1. Summary of main findings of cross-sectional studies investigating the relation between chronotype and diet 1.
To date, there are limited studies that have investigated the association between chronotype and diet in infants and young children. When considered in light of the detrimental influence of evening chronotype on various dimensions of dietary intake and eating behavior in adolescents and adults 20 , 24 , 74 , 75 , 80 , understanding how variations in chronotype in young children influence the development of dietary habits and eating patterns appears to be imperative. A recent review concluded that, as early as during fetal development, disruption of circadian rhythms in the mother may adversely affect fetal development and growth One feature of circadian misalignment is the altered timing of nutrient supply to the fetus, which may potentially play a role that is yet to be fully elucidated Most of the evidence on the impact of chronodisruption on gestational development is currently based on animal models, and few studies have investigated how variations in chronotype among mothers influence long-term offspring health in humans The association between maternal disruptions of chronotype such as those induced by modifiable factors and long-term child health also remains to be explored.
After birth, the development of the h circadian rest-activity rhythm is observed in infants as young as 3 wk old and is potentially influenced by a mother's rest-activity cycle 88 and maternal melatonin rhythm Breast milk is also believed to play an important role in determining the circadian phase in infants, which is evident by the circadian variation in nutrient composition of breast milk 90—93 and cytokine concentrations The few studies that have investigated chronotype in young children, through the use of the Children's Chronotype Questionnaire or DLMO, all have repeatedly observed a greater prevalence of morning chronotype in young children 5 , 94 , The implications of the differing chronotype trajectories on dietary behavior and diet quality remain unknown.
The factors that determine the shift from morning to evening chronotype also remain to be clarified. It could be hypothesized that after a certain age, children begin to shift their rhythms to follow parental social schedules and eventually daycare or school schedules, which may interfere with their circadian phase preference and sleep time 97 , leading to greater prevalence of the evening chronotype.
In this respect, the role of diet in synchronizing the biological rhythms remains to be clarified. In the latter study, the foods with the highest tryptophan content included meat, bread or rice, fish, natto, and milk. The dietary intervention involved asking children to drink milk at breakfast and to get up early and to eat breakfast. However, in the latter study, the circadian typology was only assessed via a subjective questionnaire with no objective biological measures such as DLMO. As a result, it is not clear if the intervention induced any changes in the circadian clock mechanism or physiology as opposed to simply changing behavior.
Several cross-sectional studies indicate that chronotype might be an important determinant of dietary intake in adolescents. Later bed- and rise times have been found to be associated with increased likelihood of caffeinated drink and fast-food consumption and a lower likelihood of dairy product consumption in a small-scale cross-sectional survey of adolescents Several other studies have reported cross-sectional associations between an evening chronotype and higher consumption of stimulants such as caffeine, energy drinks, sugar-sweetened beverages, and alcohol in adolescents 24 and in college or university students 49 , 78 , 79 , In another study involving students and professionals, individuals with an evening chronotype were found to consume more alcohol, coffee, and cola, whereas morning types consumed more tea In addition to stimulant consumption, several studies have reported an association between an individual's chronotype and dietary intake of selected food groups, energy, macronutrients, and micronutrients.
In a large-scale cross-sectional study involving female dietetics students from 53 institutions in Japan, the midpoint of sleep was assessed by calculating the midpoint between self-reported bedtimes and rise times A late midpoint of sleep was associated with a lower percentage of energy from protein and carbohydrates and a lower intake of rice, vegetables, pulses, eggs, and milk products It was, however, associated with a higher percentage of energy from alcohol and fat and higher intake of noodles, confectionery, fats and oils, and meat.
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In another study, individuals with an evening chronotype likewise had inadequate intakes of several minerals and vitamins including calcium, magnesium, zinc, and vitamin D, riboflavin, and vitamin B-6 More recently, Diederichs et al. Besides dietary intake, studies suggest that individuals with a morning chronotype exhibit more regular eating behavior than individuals with an evening chronotype 83 , Adolescents with an evening chronotype experience greater shifts in timing of breakfast consumption between weekdays and weekends, with later awakening times during weekends corresponding to later breakfast consumption This irregularity in timing of eating based on an individual's chronotype has also been reported in relation to timing of lunch 76 , Considering that dietary habits persist from adolescence into adulthood , and that cardiometabolic disease risk factors are often formed in childhood and adolescence , understanding how chronotype influences diet quality and eating patterns in childhood and adolescence is essential in guiding the development of dietary strategies to prevent chronic disease development.
This is particularly true considering that irregularity of meal patterns has been identified as a novel risk factor for cardiometabolic disorders One key limitation of the previously described studies is the cross-sectional design where associations are reported but causality is not investigated. It remains unclear whether changing an individual's behavioral chronotype might alter their physiologic chronotype or dietary intake. In a randomized crossover design study, 67 adolescents were asked to change bedtimes to create 5-night periods of sleep restriction 6.
During the intervention involving healthy sleep, adolescents with a morning chronotype were found to reduce their evening energy intake, whereas no changes in evening energy intake were seen in adolescents with an evening chronotype. The authors concluded that subsequent studies should investigate if, in adolescents with an evening type, extending sleep time by waking up later, rather than advancing bedtime, might have a greater effect on their dietary energy intake Comparable with findings in adolescents and young adults, data from the UK Biobank project demonstrate that adults with a morning chronotype consume a mean of 0.
Similarly, in a random sample of the Finnish population, chronotype was assessed via a shortened version of the MEQ Dietary data were collected with the use of a validated FFQ. Greater eveningness, as demonstrated by lower morning-to-evening score, was associated with a lower intake of whole grains, rye, potatoes, and vegetables and roots, whereas intake of wine and chocolate was higher.
Intakes of alcohol as a percentage of total energy intake and sucrose were also higher, whereas intakes of carbohydrates, protein, fiber, folic acid, and sodium were lower with lower morning-to-evening scores Evening types were found to have a lower adherence to the Baltic Sea dietary pattern and were more likely to be smokers, physically inactive, and have lower perceived health than other chronotypes In addition to studies on individual foods and dietary patterns, a recent study in Finland investigating the relation between chronotype and chrono-nutrition found that evening types reported lower energy and macronutrient intakes in the morning compared with morning types according to data collected through the use of h food recalls By contrast, in the evening, evening types reported higher intakes of energy, sucrose, fat, and saturated fatty acids than did morning types.
These differences were more pronounced in the weekends and evening types reported eating more frequently and irregularly than morning types Consistent with the Finnish study, one study in Japan found that adults with an evening chronotype are more likely to skip meals more frequently and to have a higher probability of watching television at breakfast, lunch, and dinner A further study involving 72 physicians reported that greater morningness was associated with lower consumption of sweets and vegetables as assessed via a 3-d food record and greater leisure-time physical activity Inverse associations between later bedtime, wake time, or midpoint of sleep and time spent in moderate-to-vigorous physical activity or sedentary behavior have been noted in other studies 73 , Considering that adults with an evening chronotype skip breakfast more often than do individuals with a morning chronotype 19 , and that breakfast skipping has been related to lower physical activity in some studies , it remains to be determined whether the observed differences in physical activity between the 2 chronotypes may also be explained by breakfast-consumption habits.
Alternatively, it could be argued that modifiable factors such as physical activity and eating behavior might form part of a broader phenotype that may interact cumulatively to affect physiology. Consistent with the findings in adolescents, young adults, and adults, older adults with an evening chronotype have been found to consume more caffeinated beverages at night, eat heavier meals before bedtime, have irregular sleep-wake schedules, and nap more frequently In particular, elderly individuals with an evening chronotype were more likely to be current smokers, have more sleep disturbances, engage in more sleep-interfering behaviors i.
To our knowledge, this is the only study that has investigated the impact of chronotype on diet in the elderly. Severe circadian misalignment has long been recognized to be a risk factor for the development of cardiovascular diseases Most of this evidence is derived from studies on different models of shift work, which found that shift workers working during their circadian night are more likely to develop metabolic disturbances This evidence has been replicated in animal models of shift work, recently reviewed , as well as in human interventions involving experimentally induced circadian misalignment , More recent research findings suggest that mild circadian misalignment, experienced as minor shifts between the sleep-awake cycle in non—shift workers, is also detrimental to health 50 , Although chronotype was not assessed in that study, the authors argued that men are more likely to have an evening chronotype and accumulate sleep debt during the time transition, which may lead to acute myocardial infarction.
An adverse impact of time transitions on sleep has also been reported in adolescents with an evening chronotype It is known that cerebrovascular and cardiovascular events exhibit a bimodal pattern Strokes, for instance, follow a circadian rhythm with a major morning peak and a secondary early evening peak.
This circadian rhythm is believed to reflect the circadian rhythms of vascular tone, coagulative balance, and blood pressure and may be affected by the temporal patterns of exogenous factors such as eating behavior and physical activity Because chronotype is a determinant of the bimodality of sleep-awake and fasting-feeding cycles, researchers hypothesized that chronotype may correlate with cerebrovascular and cardiovascular disease risk 12 , In relation to cardiovascular risk factors, the evidence appears to be more consistent. These associations occurred independently of sleep duration and sufficiency Taken together, this evidence implies that chronotype may modulate physiologic processes linked to cardiovascular health, including heart rate, blood pressure, and blood lipid concentrations.
The molecular basis of such associations warrants further investigation and may potentially be mediated by lifestyle factors including diet. Moreover, given the limited research in this area, it remains to be determined if variations in chronotype during childhood or adolescence could influence trajectories of cardiovascular disease risk factors later in life, and whether this effect could be modulated by timing of eating among other components of chrono-nutrition.
Glucose metabolism is another example of a physiologic process that follows a circadian rhythm. In humans, glucose tolerance generally declines over the course of the day, reaching a nadir in the evening. This circadian rhythmicity of glucose metabolism arises as a consequence of changes in glucose utilization, insulin sensitivity, and insulin secretion based on the time of day Different forms of shift work are reported to induce multiple forms of circadian misalignment, which are believed to underlie the observed raised postprandial glucose and insulin concentrations in shift workers , as well as the increased risk of impaired glucose tolerance and type 2 diabetes observed in epidemiologic studies A recent meta-analysis of 12 observational studies found that among different types of shift work, rotating shift work is associated with increased risk of type 2 diabetes In experimental studies, a combination of circadian misalignment and sleep restriction has been shown to reduce insulin sensitivity , increase inflammation , and impair glucose tolerance In one particular study, circadian misalignment led some subjects to exhibit postprandial glucose responses akin to the range observed in prediabetes Together, such findings imply that circadian misalignment may predispose individuals to the development of type 2 diabetes.
Likewise, in the Korean Genome and Epidemiology Study, evening chronotype, compared with morning chronotype, was associated with a higher prevalence of diabetes and metabolic syndrome after adjustment for age, sex, smoking, alcohol, exercise, occupation, sleep duration, and medications for hypertension, diabetes, and dyslipidemia, and in addition, after adjustment for BMI in the analysis on diabetes Interestingly, in the latter study, sex differences in the association were evident, wherein evening chronotype was related to diabetes in men and to metabolic syndrome in women Besides possible associations with type 2 diabetes development, chronotype has been related to glycemic control in individuals with diabetes.
In a study in patients with type 2 diabetes who were non—shift workers, patients completed an interview and questionnaires on diabetes history, habitual sleep duration, and sleep timing Chronotype was assessed with the use of the Composite Score of Morningness and with the use of mid-sleep time on free days. Later bedtime on weekends was related to both shorter sleep duration and poorer glycemic control The mechanisms underlying the association between chronotype and disturbances in glucose metabolism need to be elucidated, but are likely to be multifactorial.thisislamu.com/juxo-le-gua.php
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For instance, experimental sleep loss, such as induced by circadian misalignment and social jet lag, reduces insulin sensitivity and induces inflammation , which may, in turn, modulate insulin sensitivity and is a risk factor for cardiometabolic disturbance Chronotype may also affect dietary intake and eating patterns, which could in the short term influence glucose metabolism and potentially in the long term lead to type 2 diabetes and the metabolic syndrome , More recently, variants of circadian clock genes associated with chronotype and sleep homeostasis have been linked to glucose metabolism , potentially pointing towards the existence of an underlying network between circadian clocks, chronotype, and glucose homeostasis.
Differences in dietary habits between type 2 diabetes patients with a morning as opposed to an evening chronotype have been observed. Data on breakfast skipping and diet were collected with the use of h dietary recall, whereas glycated hemoglobin HbA1c values were obtained from medical records. Overall, 22 Those individuals were found to have significantly higher HbA1c concentrations, higher BMI, and later midpoint of sleep than breakfast eaters.
Breakfast skipping was related to higher HbA1c values, even after adjusting for age, sex, race, BMI, number of diabetes complications, insulin use, depressive symptoms, perceived sleep debt, and percentage of daily caloric intake at dinner. In an earlier study, later chronotype and having a large dinner were associated with poorer glycemic control independently of sleep disturbances Whether similar findings could be observed in prediabetes remains to be clarified.
In this review, the applicability of various methodologies to assess chronotype in the context of epidemiology was evaluated, alongside the current epidemiologic evidence of the relation between chronotype, dietary intake, and cardiometabolic health. In relation to chronotype assessment, the applicability of the different methodologies used to assess chronotype remains to be established. It was evident that the use of subjective questionnaires is a common practice in epidemiologic studies. An objective measure of the internal circadian phase might still be necessary to test hypotheses concerning how chronotype influences dietary intake and modifies, confounds, or mediates the relation between timing of energy or nutrient intake and health.
In this respect, existing research on metabolomics and transcriptomics or the use of noninvasive methods of measuring circadian phase warrants further investigation 29— As for determinants, a number of nonmodifiable and modifiable factors influencing chronotype were identified. These determinants include genetic factors and environmental factors such as cultural influences, urban lifestyle, environmental factors, family, and social schedules. These factors were selected based on their impact on dietary behavior and should, as such, be considered as potential confounders when examining the association between chronotype and diet.
What remains to be clarified are the relative contribution of each of these determinants to chronotype and how the interaction between these different factors affects chronotype over various stages of the life course. Given the cross-sectional nature of most studies, the direction of the causal pathway also remains to be determined. For instance, whether individuals with an evening type generally prefer working night shifts or whether working schedules impose and dictate the circadian typology of an individual.
These factors are summarized within Figure 1 , which provides a framework for epidemiologic studies investigating the relation between chronotype, chrono-nutrition, and cardiometabolic health outcomes. A similar point emerges in epidemiologic evidence, wherein most of the evidence of the association between chronotype and diet, or chronotype and cardiometabolic health, is based on cross-sectional studies that do not permit identification of cause and effect or temporality of associations.
Studies were also limited by the unrepresentativeness of the samples, mainly due to the small sample size, by selection bias, and by other inherent biases of observational studies. This is not to mention the limited evidence in specific population subgroups such as infants, older adults, and those at risk of developing cardiovascular diseases or type 2 diabetes. Dietary assessment methods varied, with most studies using either FFQs or h food recalls, which either do not capture the timing of consumption or do not permit assessment of the variability in intake between different days.
The latter are key issues considering that timing of macronutrient intake has been shown to affect the circadian clock in rodent models, with little data from human studies 16 , Thus, in addition to studying relations with overall diet, it is imperative that surveys and cohort studies adopt dietary assessment methods that permit capturing the temporal aspects of energy and nutrient intake.
In this respect, novel advances in the use of technology-based dietary assessment may provide opportunities to better capture the various dimensions of chrono-nutrition A further limitation is that none of the studies cited herein assessed the context within which foods are consumed at different time points, to identify if there are associations between the socioenvironmental factors and consumption of specific nutrients at a given eating occasion.
The implication is that further studies are needed involving population-based samples, more appropriate dietary assessment methods, and more advanced statistical analyses that permit capturing of temporal trends of energy and nutrient intake. The latter is important considering that chronotype may not only influence specific aspects of overall food, energy, and macronutrient intake but might also be related to different dimensions of eating patterns including the timing, frequency, and regularity of meals. Understanding how chronotype influences or is influenced by diet and eating patterns is essential in guiding the development of appropriate dietary strategies to prevent chronic disease development.
This is particularly true considering that no study has examined whether chronotype could affect the association between diet and cardiometabolic health across various stages of the life course.
In conclusion, scientific evidence is providing increasing insight into the relation between chronotype, diet, and cardiometabolic health. Overall, cross-sectional studies suggest that evening chronotype is associated with lower intake of fruits and vegetables and higher intake of energy drinks, alcoholic, sugary, and caffeinated beverages, as well as higher energy intake from fat. A limited number of observational studies also demonstrate that evening chronotype is potentially related to changes in timing of food intake, irregular eating, and meal skipping, particularly breakfast skipping.
However, further research on the best methods to assess chronotype is required to consolidate the research fields of chronobiology and chrono-nutrition and to examine how chronotype may affect the association between chrono-nutrition and long-term cardiometabolic health. The latter will potentially guide the development of health-promotion strategies aimed at preventing and treating chronic diseases based on an individual's chronotype.
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Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Sign In or Create an Account. Sign In. Advanced Search. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents. Current Status of Knowledge. Oxford Academic. Google Scholar. Snieguole Vingeliene. Frederic Gachon. Trudy Voortman. Luigi Palla. Jonathan D Johnston. Rob Martinus Van Dam. Christian Darimont. Leonidas G Karagounis.
Address correspondence to LGK e-mail: leonidas. Cite Citation. Permissions Icon Permissions. ABSTRACT Chrono-nutrition is an emerging research field in nutritional epidemiology that encompasses 3 dimensions of eating behavior: timing, frequency, and regularity. Open in new tab Download slide. TABLE 1. Open in new tab. TABLE 2. Food deprivation was longer in evening types, particularly in the evening. Sato-Mito et al.
Mean breakfast time at the weekend was later in late chronotypes because of their later rise times.
Nakade et al. Chrono-nutrition: a review of current evidence from observational studies on global trends in time-of-day of energy intake and its association with obesity. Search ADS. Meal timing and frequency: implications for cardiovascular disease prevention: a scientific statement from the American Heart Association. The search for circadian clock components in humans: new perspectives for association studies.
Reviewing the psychometric properties of contemporary circadian typology measures. Chronotype: a review of the advances, limits and applicability of the main instruments used in the literature to assess human phenotype. Chronotype differences in circadian rhythms of temperature, melatonin, and sleepiness as measured in a modified constant routine protocol.
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