Browsing by Author "Münch M"

Now showing 1 - 4 of 4
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    Chronotype Differences in Body Composition, Dietary Intake and Eating Behavior Outcomes: A Scoping Systematic Review
    (Elsevier Inc, 2022-11) van der Merwe C; Münch M; Kruger R
    The timing and nutritional composition of food intake are important zeitgebers for the biological clocks in humans. Thus, eating at an inappropriate time (e.g., during the night) may have a desynchronizing effect on the biological clocks and, in the long term, may result in adverse health outcomes (e.g., weight gain, obesity, and poor metabolic function). Being a very late or early chronotype not only determines preferred sleep and wake times but may also influence subsequent mealtimes, which may affect the circadian timing system. In recent years, an increased number of studies have examined the relation between chronotype and health outcomes, with a main focus on absolute food intake and metabolic markers and, to a lesser extent, on dietary intake distribution and eating behavior. Therefore, this review aimed to systematically determine whether chronotype indirectly affects eating behaviors, dietary intake (timing, choice, nutrients), and biomarkers leading to body composition outcomes in healthy adults. A systematic literature search on electronic databases (PubMed, CINAHL, MEDLINE, SCOPUS, Cochrane library) was performed (International Prospective Register of Systematic Reviews number: CRD42020219754). Only studies that included healthy adults (aged >18 y), classified according to chronotype and body composition profiles, using outcomes of dietary intake, eating behavior, and/or biomarkers, were considered. Of 4404 articles, 24 met the inclusion criteria. The results revealed that late [evening type (ET)] compared with early [morning type (MT)] chronotypes were more likely to be overweight/obese with poorer metabolic health. Both MT and ET had similar energy and macronutrient intakes, consuming food during their preferred sleep–wake timing: later for ET than MT. Most of the energy and macronutrient intakes were distributed toward nighttime for ET and exacerbated by unhealthy eating behaviors and unfavorable dietary intakes. These findings from our systematic review give further insight why higher rates of overweight/obesity and unhealthier metabolic biomarkers are more likely to occur in ET.
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    Examining the structure validity of the Pittsburgh Sleep Quality Index among female workers during New Zealand's initial COVID-19 lockdown.
    (Springer Nature, 2024-04) Helles M; Fletcher R; Münch M; Gibson R
    Sleep is important for good physical and mental health. The COVID-19 pandemic lockdown created a unique context that impacted psychological and social drivers for sleeping well. The Pittsburgh Sleep Quality Index (PSQI) is a widely used measurement tool assessing subjective sleep quality. The traditional model of the PSQI (a one-factor model), whilst validated and used across different populations, has also been questioned with regards to data fit and representativeness of its global score in different social and work-related circumstances. Examination of the structure validity of the PSQI in the unique context of the pandemic has been scarce. This study determined the PSQI structure validity amongst employed women considered to experience increased stressors during the pandemic lockdown. The subjectively reported PSQI data from 498 female workers (mean age 44.6 years) collected during New Zealand's first national COVID-19 lockdown (April, 2020) was used. Confirmatory factor analyses compared the original one-factor model of the PSQI with the two- and three-factor models used by Jia et al. (2019) within this pandemic context. Results showed that the two-factor model provided a superior fit of the PSQI data compared to the original one-factor or a three-factor model. These findings suggest that a sub-score of the PSQI with two factors appears to be better at describing the sleep quality of healthy working women during the constrained situation of the pandemic lockdown compared to a single global sleep quality score. This indicates the importance of considering the validity of subjective sleep measures when used within unique social contexts and stressors.
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    Sleeping in a bubble: factors affecting sleep during New Zealand’s COVID-19 lockdown
    (Oxford University Press on behalf of Sleep Research Society, 2022-05-16) Gibson R; Shetty H; Carter M; Münch M
    New Zealand (NZ) enforced a rigorous lockdown in response to the outbreak of COVID-19 in 2020. Infection rates remained remarkably low, yet social and personal routines were affected. Factors associated with reporting worsening sleep were explored using an anonymous online survey launched during New Zealand’s 2020 lockdown. Participants were 723 adults aged 20–85 years (median: 45 years, 82% women). Bed and wake times occurred significantly later compared to pre-lockdown estimates and resulted in shorter social jetlag (15 min). During lockdown, 54.5% were identified as “poor sleepers” [i.e. score > 5 on the Pittsburgh Sleep Quality Index (PSQI)]. Overall, 45% rated their sleep quality to worsen compared to pre-lockdown, 22% reported an improvement. Reports of worsening sleep were significantly related to increased sleep latency, reduced sleep efficiency, and heightened PSQI scores compared to those with better sleep or no change. Subjectively worse sleep was significantly associated with less time engaging in physical activity, less exposure to daylight, and social interactions compared to pre-lockdown estimates (p < .05). Logistic regression models identified significant relationships between having more vivid dreams and worsening sleep. Worse sleepers also had increased likelihoods of reporting poorer mood and they also scored higher for anxiety compared to those with no change or improved sleep during lockdown (p < .05). Pandemic-related restrictions contributed to poorer self-reported sleep which was linked to deterioration of mood. Negative affect was comparatively lower than reported elsewhere. These findings provide unique insights to the psychosocial impact of the initial COVID-19 lockdown in New Zealand, where the disease outbreak remained low.
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    The role of daylight for humans: Gaps in current knowledge
    (2020) Münch M; Wirz-Justice A; Brown SA; Kantermann T; Martiny K; Stefani O; Vetter C; Wright Jr KP; Wulff K; Skene DJ
    Daylight stems solely from direct, scattered and reflected sunlight, and undergoes dynamic changes in irradiance and spectral power composition due to latitude, time of day, time of year and the nature of the physical environment (reflections, buildings and vegetation). Humans and their ancestors evolved under these natural day/night cycles over millions of years. Electric light, a relatively recent invention, interacts and competes with the natural light–dark cycle to impact human biology. What are the consequences of living in industrialised urban areas with much less daylight and more use of electric light, throughout the day (and at night), on general health and quality of life[1, 2]? In this workshop report, we have classified key gaps of knowledge in daylight research into three main groups: (I) uncertainty as to daylight quantity and quality needed for “optimal” physiological and psychological functioning, (II) lack of consensus on practical measurement and assessment methods and tools for monitoring real (day) light exposure across multiple time scales, and (III) insufficient integration and exchange of daylight knowledge bases from different disciplines. Crucial short and long-term objectives to fill these gaps are proposed.