Frank A. J. L. Scheer

Frank A. J. L. Scheer
Harvard Medical School | HMS · Department of Medicine

PhD

About

273
Publications
52,805
Reads
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15,298
Citations
Additional affiliations
June 2019 - present
Harvard Medical School
Position
  • Professor
September 2015 - June 2019
Harvard Medical School
Position
  • Professor (Associate)
March 2009 - September 2015
Harvard Medical School
Position
  • Research Assistant
Education
May 1997 - January 2003
University of Amsterdam
Field of study
  • Neuroscience
May 1995 - May 1997
Utrecht University
Field of study
  • Neurophysiology
September 1992 - May 1995
Utrecht University
Field of study
  • Biology

Publications

Publications (273)
Article
Full-text available
Significance For centuries, it has been recognized that asthma severity shows a daily rhythm, with the worst symptoms at night. However, it is unclear to what degree this is driven by everyday behaviors, such as sleep, physical activity, and body posture changes, versus intrinsic rhythms generated by the internal body clock (i.e., the circadian sys...
Article
Night work increases diabetes risk. Misalignment between the central circadian “clock” and daily behaviors, typical in night workers, impairs glucose tolerance, likely due to internal misalignment between central and peripheral circadian rhythms. Whether appropriate circadian alignment of eating can prevent internal circadian misalignment and gluco...
Article
Full-text available
OBJECTIVE We tested whether the concurrence of food intake and elevated concentration of endogenous melatonin, as occurs in late eating, results in impaired glucose control, in particular in carriers of the type 2 diabetes–associated G allele in the melatonin receptor-1b gene (MTNR1B). RESEARCH DESIGN AND METHODS In a Spanish natural late-eating p...
Article
Full-text available
Shift workers have a 25 to 40% higher risk of depression and anxiety partly due to a misalignment between the central circadian clock and daily environmental/behavioral cycles that may negatively affect mood and emotional well-being. Hence, evidence-based circadian interventions are required to prevent mood vulnerability in shift work settings. We...
Article
Precision nutrition is an emerging concept that aims to develop nutrition recommendations tailored to different people's circumstances and biological characteristics. Responses to dietary change and the resulting health outcomes from consuming different diets may vary significantly between people based on interactions between their genetic backgrou...
Article
Full-text available
Background Emerging research suggests that food intake timing, eating behavior and food preference are associated with aspects of the circadian system function but the role that the circadian system may play in binge eating (BE) behavior in humans remains unclear. Objective To systematically evaluate the evidence for circadian system involvement i...
Article
Circadian rhythms and sleep are fundamental biological processes integral to human health. Their disruption is associated with detrimental physiological consequences, including cognitive, metabolic, cardiovascular and immunological dysfunctions. Yet many of the molecular underpinnings of sleep regulation in health and disease have remained elusive....
Article
Objective: Later circadian timing of energy intake is associated with higher body fat percentage. Current methods for obtaining accurate circadian timing are labor- and cost-intensive, limiting practical application of this relationship. This study investigated whether the timing of energy intake relative to a mathematically modeled circadian time...
Article
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 i...
Article
Context Body fat gain associated with menopause has been attributed to estradiol (E2) withdrawal. Hypoestrogenism is unlikely to be the only contributing factor, however. Objective Given the links between sleep and metabolic health, we examined the effects of an experimental menopausal model of sleep fragmentation on energy metabolism. Design Pre...
Preprint
The Circadia Study (Circadia) is a novel “direct to participant” research study investigating the genetics of circadian rhythm disorders. The long-term goals of this study are to better understand the genetics of circadian rhythm disorders, investigate the efficacy and accessibility of an at-home, self-directed DLMO collection, to improve health ou...
Article
Background: Nearly 14% of Americans experience chronic circadian disruption due to shift work, increasing their risk of obesity, diabetes, and other cardiometabolic disorders. These disorders are also exacerbated by modern eating habits such as frequent snacking and consumption of high-fat foods. Methods: We investigated the effects of recurrent...
Article
The daily rhythm of plasma melatonin concentrations is typically unimodal, with one broad peak during the circadian night and near‐undetectable levels during the circadian day. Light at night acutely suppresses melatonin secretion and phase shifts its endogenous circadian rhythm. In contrast, exposure to darkness during the circadian day has not ge...
Article
Full-text available
Background There currently are no standard, low-cost, and validated methods to assess the timing of food intake. Methods The concordance between recall based survey questions and food times estimated from multiple daily food records in 249 generally healthy, free-living adults from the SHIFT Study (ClinicalTrials.gov #NCT02997319) was assessed. At...
Article
Circadian misalignment—the misalignment between the central circadian “clock” and behavioral and environmental cycles (including sleep/wake, fasting/eating, dark/light)—results in adverse cardiovascular and metabolic effects. Potential underlying mechanisms for these adverse effects include alterations in the orogastrointestinal microbiota. However...
Article
Background : Delirium is a neurocognitive disorder characterized by an abrupt decline in attention, awareness, and cognition after surgical/illness-induced stressors on the brain. There is now an increasing focus on how cardiovascular health interacts with neurocognitive disorders given their overlapping risk factors and links to subsequent dementi...
Article
Sudden cardiac death (SCD), the unexpected death due to acquired or genetic cardiovascular disease, follows distinct 24-hour patterns in occurrence. These 24-hour patterns likely reflect daily changes in arrhythmogenic triggers and the myocardial substrate caused by day/night rhythms in behavior, the environment, and endogenous circadian mechanisms...
Article
Sudden cardiac death (SCD) is the sudden, unexpected death due to abrupt loss of heart function secondary to cardiovascular disease. In certain populations living with cardiovascular disease, SCD follows a distinct 24-hour pattern in occurrence, suggesting day/night rhythms in behavior, the environment, and endogenous circadian rhythms result in da...
Article
Full-text available
Insufficient sleep, which has been shown to adversely affect metabolism, is generally associated with prolonged exposure to artificial light at night, a known circadian disruptor. There is growing evidence suggesting that circadian disruption adversely affects metabolism, yet few studies have attempted to evaluate the adverse metabolic effects of i...
Article
Full-text available
Background Delirium is a distressing neurocognitive disorder recently linked to sleep disturbances. However, the longitudinal relationship between sleep and delirium remains unclear. This study assessed the associations of poor sleep burden, and its trajectory, with delirium risk during hospitalization. Methods 321,818 participants from the UK Bio...
Article
Introduction: Diurnal variations in physical performance can affect athletes' success in competitive sports depending on whether the time of peak performance concurs with the time of competition. The purpose of this systematic review was to investigate the diurnal variation in maximum endurance and strength performance. Methods: The databases Pu...
Article
Full-text available
Eating chocolate in the morning or in the evening/at night, may differentially affect energy balance and impact body weight due to changes in energy intake, substrate oxidation, microbiota (composition/function), and circadian‐related variables. In a randomized controlled trial, postmenopausal females (n = 19) had 100 g of chocolate in the morning...
Article
Circadian biology modulates almost all aspects of mammalian physiology, disease, and response to therapies. Emerging data suggest that circadian biology may significantly affect the mechanisms of susceptibility, injury, recovery, and the response to therapy in stroke. In this review/perspective, we survey the accumulating literature and attempt to...
Conference Paper
Full-text available
Background: Both sleep disturbance and menopause have independently been associated with weight gain in women. Possible mechanisms contributing to this weight gain may be changes in resting energy expenditure (REE) and/or nutrient utilization. Therefore, in the current study we aimed to examine the effects of experimentally induced sleep fragmentat...
Article
Chronic increases in pro-inflammatory cytokines in older adults, known as inflammaging, is an important risk factor for morbidity and mortality in the aging population. It has been suggested that circadian disruption may play a role in chronic inflammation, but there has been limited study that investigated the overall profile of 24-hour rest-activ...
Article
Objective: Moderate- to vigorous-intensity physical activity (MVPA) improves cardiovascular health. Few studies have examined MVPA timing. We examined the associations of timing of bout-related MVPA with cardiorespiratory fitness and cardiovascular risk in adults with type 2 diabetes. Research design and methods: Baseline 7-day hip-worn accelero...
Article
Full-text available
Background Spontaneous heart rate fluctuations contain rich information related to health and illness in terms of physiological complexity, an accepted indicator of plasticity and adaptability. However, it is challenging to make inferences on complexity from shorter, more practical epochs of data. Distribution entropy (DistEn) is a recently introdu...
Article
Recent cross‐sectional studies have suggested a link between sleep disturbance and worse neurocognitive function. We hypothesized that sleep disturbance traits (short/long habitual sleep duration, insomnia, daytime somnolence, and napping), and sleep apnea were linked to the development of incident Alzheimer’s disease (AD) in a large, prospective c...
Article
Full-text available
Cross-sectional observations have shown that the timing of eating may be important for health-related outcomes. Here we examined the stability of eating timing, using both clock hour and relative circadian time, across one semester (n = 14) at daily and monthly time-scales. At three time points ~ 1 month apart, circadian phase was determined during...
Article
Study Objectives Disturbances of rest-activity rhythms are associated with higher body mass index (BMI) in adults. Whether such relationship exists in children is unclear. We aimed to examine cross-sectional associations of rest-activity rhythm characteristics with BMI z-score and obesity-related inflammatory markers in school-age children. Method...
Article
Full-text available
Introduction Shift work causes misalignment between internal circadian time and the external light/dark cycle and is associated with metabolic disorders and cancer. Approximately 20% of the working population in industrialised countries work permanent or rotating night shifts, exposing this large population to the risk of circadian misalignment-dri...
Article
Full-text available
Night shift work can associate with an increased risk for depression. As night workers experience a 'misalignment' between their circadian system and daily sleep-wake behaviors, with negative health consequences, we investigated whether exposure to circadian misalignment underpins mood vulnerability in simulated shift work. We performed randomized...
Article
Background: There is a paucity of evidence regarding the role of food timing on cardiometabolic health and weight loss in adults. Objectives: To determine whether late eating is cross-sectionally associated with obesity and cardiometabolic risk factors at baseline; and whether late eating is associated with weight loss rate and success following a...
Article
Full-text available
Late eating has been shown to promote metabolic dysregulation and to be associated with obesity in adults. However, few studies have explored this association in children. We compared the presence of obesity, metabolic alterations and circadian-related disturbances between school-aged children who were early dinner eaters (EDE) or late dinner eater...
Article
Objective: Disruption of rest-activity rhythms is cross-sectionally associated with metabolic disorders, including type 2 diabetes, yet it remains unclear whether it predicts impaired glucose metabolism and homeostasis. The aim of this study is to examine the cross-sectional and prospective associations between rest-activity rhythm characteristics...
Article
Background Fat mobilization in adipose tissue (AT) has a specific timing. However, circadian rhythms in the activity of the major enzyme responsible for fat mobilization, Hormone-Sensitive Lipase (HSL) have not been demonstrated in humans. Objective To analyze in a cross–sectional study, whether there is an endogenous circadian rhythm in HSL activ...
Article
Objectives Eating at times that conflict with our physiology and coincide with the biological evening has been associated with increased disease risk. In free-living adults from the ONTIME-MT study (#NCT03036592) study, we tested the hypothesis that advancing the timing of dinner relative to bedtime, simulated by advancing an evening oral glucose t...
Article
Background: Moderate-to-vigorous physical activity (MVPA) is an important treatment in type 2 diabetes (T2D). Few studies examine the timing of MVPA, as there are no established methods to characterize the MVPA bout timing throughout the day. We determined the timing of MVPA bouts in adults with T2D, and examined whether cardiorespiratory fitness a...
Conference Paper
Full-text available
Introduction Cognitive performance may be adversely affected during the menopause transition from hot flash-induced sleep fragmentation even without changes in sleep duration. We examined the effects of experimentally-induced sleep fragmentation without shortened sleep duration on daytime sleepiness and neurobehavioral performance in women in a hig...
Article
Full-text available
Introduction In the current epidemic of opioid-related deaths, and widespread use of opioids to treat chronic pain, there is a pressing need to understand the underlying risk factors that contribute to such devastating conditions. Shiftwork has been associated with adverse health outcomes. We tested whether shiftwork during middle age is linked to...
Article
Full-text available
Introduction People with a later chronotype typically sleep later and perform better later in the day. In an early high school schedule, students with later chronotypes earn lower average grades than those with earlier chronotypes. However, other effects of late chronotype on high school students are poorly understood. This study examined the relat...
Article
Full-text available
Introduction Nearly 14% of Americans experience chronic circadian disruption due to shift work, increasing their risk of obesity and cardiometabolic disorders. These disorders are also exacerbated by modern eating habits such as frequent snacking and consumption of high-fat foods. Here we used a forced desynchrony protocol to investigate the effect...
Preprint
Full-text available
Shift work causes misalignment between our internal clock and daily behavioural cycles and is associated with metabolic disorders and cancer. Here, we describe the relationship between shift work and prevalent asthma in >280,000 UK Biobank participants. Compared to day workers, permanent night shift workers had a higher likelihood of moderate/sever...
Data
Recent studies indicate that the timing of food intake can significantly affect metabolism and weight management. Workers operating at atypical times of the 24-h day are at risk of disturbed feeding patterns. Given the increased risk of weight gain, obesity and metabolic syndrome in shift working populations, further research is required to underst...
Article
Full-text available
Recent studies indicate that the timing of food intake can significantly affect metabolism and weight management. Workers operating at atypical times of the 24-h day are at risk of disturbed feeding patterns. Given the increased risk of weight gain, obesity and metabolic syndrome in shift working populations, further research is required to underst...
Article
Background The output of many healthy physiological systems displays fractal fluctuations with self-similar temporal structures. Altered fractal patterns are associated with pathological conditions. There is evidence that patients with bipolar disorder have altered daily behaviors. Methods To test whether fractal patterns in motor activity are alt...
Article
Obstructive sleep apnea (OSA) is associated with hypertension, cardiovascular disease, and a change in the 24 h pattern of adverse cardiovascular events and mortality. Adverse cardiovascular events occur more frequently in the middle of the night in people with OSA, earlier than the morning prevalence of these events in the general population. It i...
Article
The past decade has witnessed a revival of interest in the hormone melatonin, partly attributable to the discovery that genetic variation in MTNR1B - the melatonin receptor gene - is a risk factor for impaired fasting glucose and type 2 diabetes (T2D). Despite intensive investigation, there is considerable confusion and seemingly conflicting data o...
Article
Full-text available
The circadian system generates endogenous rhythms of approximately 24 h, the synchronisation of which are vital for healthy bodily function. The timing of many physiological processes, including glucose metabolism, are coordinated by the circadian system, and circadian disruptions that desynchronise or misalign these rhythms can result in adverse h...
Article
Night shift work, behavioral rhythms, and the common MTNR1B risk single nucleotide polymorphism (SNP), rs10830963, associate with type 2 diabetes, however, whether they exert joint effects to exacerbate type 2 diabetes risk is unknown. Among employed participants of European ancestry in the UK Biobank (N=189,488), we aimed to test the cross-section...
Article
Shift work causes circadian misalignment and is a risk factor for obesity. While some characteristics of the human circadian system and energy metabolism differ between males and females, little is known about whether sex modulates circadian misalignment effects on energy homeostasis. Here we show—using a randomized cross-over design with two 8-d l...
Article
A cross-sectional study shows that proxies of circadian misalignment, such as late chronotype and social jet lag, are associated with increased adiposity in adolescent girls but not adolescent boys, highlighting a potential sex-specific effect of circadian misalignment. Interventions targeting sleep timing should be considered in the prevention of...
Article
Study Objectives Recovery rates of systolic blood pressure (BP) and heart rate (HR) after exercise have been used to assess cardiovascular fitness, and slower recovery rates are predictors of coronary heart disease and cardiac mortality. The endogenous circadian system is known to modulate BP and HR at rest and during exercise. Here we examined whe...
Article
Full-text available
Background: Timing of dietary intake may play a role in obesity. However, previous studies produced mixed findings possibly due to inconsistent approaches to characterize meal timing and not taking into account chronotype and macronutrients. To address the aforementioned limitations, we have defined meal timing relative to sleep/wake timing, inves...
Article
Full-text available
Excessive daytime sleepiness (EDS) affects 10-20% of the population and is associated with substantial functional deficits. Here, we identify 42 loci for self-reported daytime sleepiness in GWAS of 452,071 individuals from the UK Biobank, with enrichment for genes expressed in brain tissues and in neuronal transmission pathways. We confirm the aggr...
Article
Full-text available
The human circadian system regulates hunger independently of behavioral factors, resulting in a trough in the biological morning and a peak in the biological evening. However, the role of the only known orexigenic hormone, ghrelin, in this circadian rhythm is unknown. Furthermore, although shift work is an obesity risk factor, the separate effects...
Article
The circadian system, that is ubiquitous across species, generates ∼24 h rhythms in virtually all biological processes, and allows them to anticipate and adapt to the 24 h day/night cycle, thus ensuring optimal physiological function. Epidemiological studies show time-of-day variations in adverse cardiovascular (CV) events, and controlled laborator...
Article
Observations that mistimed food intake may have adverse metabolic health effects have generated interest in personalizing food timing recommendations in interventional studies and public health strategies for the purpose of disease prevention and improving overall health. Small, controlled, and short-termed intervention studies suggest that food ti...
Article
Background: Little is known about the contribution of genetic variation to food timing, and breakfast has been determined to exhibit the most heritable meal timing. As breakfast timing and skipping are not routinely measured in large cohort studies, alternative approaches include analyses of correlated traits. Objectives: The aim of this study w...
Article
Objectives: Emerging epidemiological and experimental studies suggest that food timing associates with obesity, weight-loss success, and other adverse cardiometabolic health outcomes. Although anecdotally simple to ascertain, the validity of recalled food timing has not been evaluated against prospectively collected data and current methods do not...
Article
The risk for adverse cardiovascular events (e.g., myocardial infarction, sudden cardiac death) peaks in the morning, possibly due to the effects of the endogenous circadian system on cardiovascular risk factors, or the occurrence in the morning of specific triggers, such as mental stress. To assess any interacting effects on cardiovascular function...
Article
Full-text available
Introduction Sleep-wake regularity (SWR) is often disrupted in early adult life. Repetitive and long-term misalignment between environmental and behavioral cycles may have subsequent psychological and physical health consequences, including autonomic function. We tested whether SWR was independently associated with mood an