Physical activity, sleep duration and metabolic health in children fluctuate with the lunar cycle: science behind the myth
Open accessAbstract
Summary: Behaviours of several animal species have been linked to lunar periodicity. Evidence for such links in humans is weak; however, recently, shorter sleep duration was reported around full moon in two small samples of adults. As restrictions in sleep duration have been shown to adversely affect glucose regulation and physical activity to improve glucose regulation, one could speculate that cardiometabolic risk factors might also be affected by the lunar phase. We retrospectively examined 795 D anish children, aged 8–11 years, with more than 13 000 24‐h accelerometer recordings of activity and sleep as well as 2000 measurements of different cardiometabolic risk factors, including insulin sensitivity, appetite hormones and blood pressure, during nine lunar phases. During the period around full moon, children were 5.0 and 3.2 min per day less active, slept 2.4 and 4.1 min per night longer, had 0.03 and 0.05 higher homeostatic model assessment of insulin resistance and 0.6 and 0.8 mm H g higher mean arterial blood pressure compared with days around half moon and new moon, respectively (all P ≤ 0.02). Furthermore, ghrelin was lower and leptin was higher during the period around full moon compared with days around half moon (both P < 0.001). The results suggest that physical activity rather than sleep is responsible for the metabolic alterations observed around full moon. However, we have no understanding of potential mechanisms that may mediate a potential true link between childhood behaviour and the lunar cycle or confounders that may explain this, apparently leading to fluctuation in a number of cardiometabolic risk markers conjointly with lunar phases.
AI snapshot
Written from the paper’s full text.
TL;DR
In 795 Danish children aged 8–11 years, physical activity, sleep duration, and several cardiometabolic risk markers varied with lunar phase, with less activity, slightly longer sleep, higher insulin resistance, and higher blood pressure around full moon. The authors suggest physical activity rather than sleep may explain the metabolic differences, but state that mechanisms and possible confounders remain unknown.
Key findings
- Around full moon, children were 5.0 and 3.2 min/day less physically active and slept 2.4 and 4.1 min/night longer compared with half moon and new moon, respectively (all P ≤ 0.02).
- HOMAIR was 0.03 and 0.05 higher, and mean arterial blood pressure was 0.6 and 0.8 mmHg higher, around full moon compared with half moon and new moon (all P ≤ 0.02); insulin, glucose, and diastolic blood pressure were also higher at full moon (all P ≤ 0.04).
- Ghrelin was 29 pg/mL lower and leptin was 1.2 pg/mL higher at full moon compared with half moon (both P < 0.001).
- No lunar-phase differences were found for sedentary time, light physical activity, CRP, IL-6, adiponectin, HDL cholesterol, LDL cholesterol, triglycerides, or resting heart rate (all P > 0.15). Correlations were reported between moderate-to-vigorous physical activity and sleep duration (r = −0.12, P = 0.01), moderate-to-vigorous physical activity and HOMAIR (r = −0.25, P < 0.001), and sleep duration and HOMAIR (r = −0.16, P < 0.001).
Methods
- Retrospective analysis of 795 children aged 8–11 years from nine Danish municipal schools in the OPUS school meal study, using data from three measurement periods and 13,464 daytime activity observations, 13,762 sleep observations, and 2,005–2,148 cardiometabolic observations across nine lunar cycles.
- Children wore hip-mounted ActiGraph accelerometers for seven consecutive days and eight nights; sleep duration was estimated from parent/child bedtime logs plus the Sadeh algorithm, and cardiometabolic markers included fasting glucose, insulin, HOMAIR, blood pressure, ghrelin, leptin, CRP, IL-6, adiponectin, and blood lipids.
- An available-case linear mixed model with school, class, and subject as random effects and weekday, month, age, gender, Tanner stage, number of parents born in Denmark, and parental education as fixed effects compared full moon ±4 d with half moon ±5–9 d and new moon ±10–14 d.
Limitations
- The paper states that it lacks understanding of potential mechanisms linking childhood behaviour and the lunar cycle, and of confounders that could explain the associations.
- The authors state that the sleep-duration differences were small and of questionable biological relevance, that accelerometers cannot detect sleep stages, and that fixed weekday wake times for school may have limited the ability to detect sleep effects.
- The paper notes that P-values were not adjusted for multiple testing, though it indicates which significant associations vanished after Bonferroni adjustment; it is also an observational study, so causality cannot be inferred, and findings are from Danish children aged 8–11 years, which may limit generalizability.
Model-written summary. Check it against the paper before relying on it.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
0 of 16 cited sources checked · 0 supported · 0 flagged
- Findingown data
Sleep duration was 4.1 min per night longer at full moon compared with new moon.
“As shown in Table 2, accelerometer-determined moderate-to-vigorous physical activity was 5.0 and 3.2 min per day lower (both P < 0.001) and sleep duration was 2.4 and 4.1 min per night longer (all P ≤ 0.02) at full moon compared with half moon and new moon, respectively.”
Quote in the paperSubstantial claim - Findingown data
Moderate-to-vigorous physical activity was negatively correlated with sleep duration (r = −0.12, P = 0.01).
“we tested and found a negative correlation between moderate-to-vigorous physical activity and sleep duration (r = −0.12, P = 0.01)”
Quote in the paperNot a substantial claim - Findingown data
Mean arterial blood pressure was 0.6 mmHg higher at full moon compared with half moon.
“had 0.03 and 0.05 higher homeostatic model assessment of insulin resistance and 0.6 and 0.8 mmHg higher mean arterial blood pressure compared with days around half moon and new moon, respectively (all P ≤ 0.02).”
Quote in the paperSubstantial claim - Findingown data
Leptin was 1.2 pg/mL higher at full moon compared with half moon.
“Furthermore, leptin was 1.2 pg mL−1 higher and ghrelin 29 pg mL−1 lower at full moon compared with half moon (both P < 0.001).”
Quote in the paperNot a substantial claim - Findingown data
HOMAIR was 0.05 higher at full moon compared with new moon.
“had 0.03 and 0.05 higher homeostatic model assessment of insulin resistance and 0.6 and 0.8 mmHg higher mean arterial blood pressure compared with days around half moon and new moon, respectively (all P ≤ 0.02).”
Quote in the paperSubstantial claim
- Findingown data
Moderate-to-vigorous physical activity was negatively correlated with HOMAIR (r = −0.25; P < 0.001).
“between moderate-to-vigorous physical activity and HOMAIR (r = −0.25; P < 0.001)”
Quote in the paperNot a substantial claim - Findingown data
HOMAIR was 0.03 higher at full moon compared with half moon.
“had 0.03 and 0.05 higher homeostatic model assessment of insulin resistance and 0.6 and 0.8 mmHg higher mean arterial blood pressure compared with days around half moon and new moon, respectively (all P ≤ 0.02).”
Quote in the paperSubstantial claim - Findingown data
Sleep duration was 2.4 min per night longer at full moon compared with half moon.
“As shown in Table 2, accelerometer-determined moderate-to-vigorous physical activity was 5.0 and 3.2 min per day lower (both P < 0.001) and sleep duration was 2.4 and 4.1 min per night longer (all P ≤ 0.02) at full moon compared with half moon and new moon, respectively.”
Quote in the paperSubstantial claim - Findingown data
Moderate-to-vigorous physical activity was 3.2 min per day lower at full moon compared with new moon.
“As shown in Table 2, accelerometer-determined moderate-to-vigorous physical activity was 5.0 and 3.2 min per day lower (both P < 0.001) and sleep duration was 2.4 and 4.1 min per night longer (all P ≤ 0.02) at full moon compared with half moon and new moon, respectively.”
Quote in the paperSubstantial claim - Findingown data
Ghrelin was 29 pg/mL lower at full moon compared with half moon.
“Furthermore, leptin was 1.2 pg mL−1 higher and ghrelin 29 pg mL−1 lower at full moon compared with half moon (both P < 0.001).”
Quote in the paperNot a substantial claim - Findingown data
Moderate-to-vigorous physical activity was 5.0 min per day lower at full moon compared with half moon.
“As shown in Table 2, accelerometer-determined moderate-to-vigorous physical activity was 5.0 and 3.2 min per day lower (both P < 0.001) and sleep duration was 2.4 and 4.1 min per night longer (all P ≤ 0.02) at full moon compared with half moon and new moon, respectively.”
Quote in the paperSubstantial claim - Findingown data
Sleep duration was negatively correlated with HOMAIR (r = −0.16; P < 0.001) after adjustment for sleep duration and moderate-to-vigorous physical activity.
“between sleep duration and HOMAIR (r = −0.16; P < 0.001) after adjustment of sleep duration and moderate-to-vigorous physical activity, respectively.”
Quote in the paperNot a substantial claim - Findingown data
Glucose was higher at full moon compared with half moon and new moon.
“Cardiometabolic risk markers as HOMAIR, insulin, glucose, mean arterial blood pressure and diastolic blood pressure were all higher at full moon compared with half moon and new moon (all P ≤ 0.04)”
Quote in the paperSubstantial claim - Findingown data
Insulin was higher at full moon compared with half moon and new moon.
“Cardiometabolic risk markers as HOMAIR, insulin, glucose, mean arterial blood pressure and diastolic blood pressure were all higher at full moon compared with half moon and new moon (all P ≤ 0.04)”
Quote in the paperSubstantial claim - Findingown data
Diastolic blood pressure was higher at full moon compared with half moon and new moon.
“Cardiometabolic risk markers as HOMAIR, insulin, glucose, mean arterial blood pressure and diastolic blood pressure were all higher at full moon compared with half moon and new moon (all P ≤ 0.04)”
Quote in the paperSubstantial claim - Interpretationcitation
Lunar phase-associated variations in ghrelin and leptin were in directions that could favour a positive energy balance during the period around full moon.
“In addition, we found lunar phase-associated variations in ghrelin and leptin in directions that could favour a positive energy balance during the period around full moon 21.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [21] source
Not checked in the free run.
- Premisecitation
Restrictions in sleep duration adversely affect glucose regulation.
“As restrictions in sleep duration have been shown to adversely affect glucose regulation 6”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [6] source
Not checked in the free run.
- Study design and conductcitation
We adjusted for a large number of potential confounders shown to affect physical activity and sleep duration in this group of children.
“Further, we adjusted for a large number of potential confounders shown to affect physical activity and sleep duration in this group of children 9.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [9] source
Not checked in the free run.
- Interpretationown data
The paper offers evidence in support of an effect of lunar rhythmicity on human behaviour and metabolic health.
“Using more than 13 000 d and nights of objectively measured behaviour and more than 2000 measurements of different cardiometabolic risk factors across nine lunar cycles, this paper offers evidence in support of an effect of lunar rhythmicity on human behaviour and metabolic health.”
Quote in the paperSubstantial claim - Interpretationreasoning
It is very unlikely that our findings could be explained by other sources of variation (e.g., uneven distribution of age and gender).
“Therefore, it is very unlikely that our findings could be explained by other sources of variation (e.g. uneven distribution of age and gender), as might have been the case in the study by Cajochen et al., where there were almost three times as many older subjects around full moon compared with new moon 4.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [4] source
Not checked in the free run.
- Study design and conductown data
Adjusting for the fact that the three repeated measures came from baseline, control and intervention did not affect the observed associations between metabolic variables and lunar phases.
“Adjusting for the fact that the three repeated measures came from baseline, control and intervention did not affect the observed associations between metabolic variables and lunar phases.”
Quote in the paperNot a substantial claim - Interpretationown data
The results suggest that physical activity rather than sleep is responsible for the metabolic alterations observed around full moon.
“The results suggest that physical activity rather than sleep is responsible for the metabolic alterations observed around full moon.”
Quote in the paperSubstantial claim - Interpretationown data
The negative correlation between sleep duration and HOMAIR does not fit with HOMAIR being highest during full moon.
“However, the differences in sleep duration were very small compared with those differences seen for moderate-to-vigorous physical activity and the negative correlation observed between sleep duration and HOMAIR does not fit with HOMAIR being highest during full moon.”
Quote in the paperSubstantial claim - Interpretationown data
The negative correlation between moderate-to-vigorous physical activity and sleep duration fits well with the observation that sleep is longest and activity lowest during full moon.
“The negative correlation between moderate-to-vigorous physical activity and sleep duration fits well with the observation that sleep is longest and activity lowest during full moon.”
Quote in the paperNot a substantial claim - Study design and conductcitation
Waist-worn ActiGraph devices can provide a valid proxy measure of sleep duration in epidemiological studies.
“we recently tested the agreement between wrist and waist-worn ActiGraph monitors using this algorithm and concluded that waist-worn devices can provide a valid proxy measure of sleep duration in epidemiological studies 12.”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [12] source
Not checked in the free run.
- Interpretationown data
Children slept somewhat longer around full moon, contrary to what has been hypothesized and recently shown in adults.
“Contrary to what has been hypothesized and recently shown in adults 4,5, children slept somewhat longer around full moon.”
Quote in the paperSubstantial claim0 of 2 sources checked - Interpretationcitation
Light exposure during the night is unlikely to have an effect on physical activity during the time awake in modern urban societies.
“In modern urban societies where most of us are surrounded by an abundance of artificial light and spend evenings and nights mostly indoors, this effect is probably minor 1 and light in the late evening and at night is unlikely to have an effect on physical activity during the time awake.”
Quote in the paperNot a substantial claim0 of 1 sources checked- cites [1] source
Not checked in the free run.
- The quote only partly states this claim. 1
- May combine two claims. 6
- Classified as probably not a substantial claim. 7
The quote only partly states this claim.
Findingown dataMean arterial blood pressure was 0.8 mmHg higher at full moon compared with new moon.
“had 0.03 and 0.05 higher homeostatic model assessment of insulin resistance and 0.6 and 0.8 mmHg higher mean arterial blood pressure compared with days around half moon and new moon, respectively (all P ≤ 0.02).”
Quote in the paperSubstantial claimMay combine two claims.
Findingown dataNo differences according to lunar phase were found for time spent sedentary, light physical activity, CRP, IL-6, adiponectin, HDL cholesterol, LDL cholesterol, triglycerides or resting heart rate.
“No differences according to lunar phase were found for time spent sedentary, light physical activity, CRP, IL-6, adiponectin, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides or resting heart rate (all P > 0.15).”
Quote in the paperSubstantial claimMay combine two claims.
Study design and conductown dataBonferroni adjustment resulted in non-significant differences in insulin and glucose between full moon and half moon; all other significant associations remained.
“Bonferroni adjustment resulted in non-significant differences in insulin (P = 0.08) and glucose (P = 0.06) between full moon and half moon; however, all other significant associations remained.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationown dataThis is the first study to demonstrate that variations in sleep duration and daytime physical activity are associated with the lunar circle and that a number of cardiometabolic risk markers fluctuated in accordance with this.
“This is the first study to demonstrate that variations in sleep duration as well as in daytime physical activity are associated with the lunar circle (∼29.5 d) and, furthermore, that a number of cardiometabolic risk markers fluctuated in accordance with this.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductown dataPresented P-values were not adjusted for multiple testing.
“Presented P-values were not adjusted for multiple testing but significant associations vanishing after Bonferroni adjustment were indicated.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
PremisecitationSleep duration was negatively affected around full moon in two small samples of adults.
“It has, however, recently been reported that sleep duration was negatively affected around full moon in two small samples of adults 4,5.”
Quote in the paperSubstantial claim0 of 2 sources checkedMay combine two claims.
Interpretationown dataChildren were less physically active during full moon and this coincided with biologically meaningful differences in several cardiometabolic risk factors, including lower insulin sensitivity and higher blood pressure, while blood lipid profile, adiponectin and markers of inflammation were not affected.
“However, we found that children were also less physically active during this period and furthermore that this coincided with biologically meaningful differences in several cardiometabolic risk factors, including lower insulin sensitivity and higher blood pressure, while the blood lipid profile, adiponectin and markers of inflammation were not affected.”
Quote in the paperSubstantial claimProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenDaytime activity was only considered valid if monitor wear time was at least 10 h per day.
“Daytime activity was only considered valid if monitor wear time was at least 10 h per day.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
PremisecitationPhysical activity has the potential to improve glucose regulation.
“physical activity has the potential to improve glucose regulation 7”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [7] source
Not checked in the free run.
May combine two claims.
PremisecitationThe school meal intervention did not affect physical activity, sedentary time and sleep duration.
“As the school meal intervention did not affect physical activity, sedentary time and sleep duration 9”
Quote in the paperSubstantial claim0 of 1 sources checked- cites [9] source
Not checked in the free run.
Probably not a substantial claim: may not pass S3 (load-bearing).
PremisecitationThe classifications of lunar phases used are identical to those used in recently published papers.
“These classifications of lunar phases are identical to what have been used in recently published papers 4,5,19 using information from a full moon calendar 20.”
Quote in the paperNot a substantial claim0 of 4 sources checkedProbably not a substantial claim: may not pass S3 (load-bearing).
Study design and conductnone givenChanges from summer to winter time and from winter to summer time were excluded from data analysis.
“Changes from summer to winter time (clock set back by 1 h) and from winter to summer time were excluded from data analysis.”
Quote in the paperNot a substantial claimClassified as probably not a substantial claim.
Study design and conductnone givenThe linear mixed model approach removes differences between children before estimates are calculated.
“Finally, the linear mixed model approach removes differences between children before estimates are calculated.”
Quote in the paperSubstantial claimMay combine two claims.
Interpretationown dataGravitational forces cannot explain our findings because large differences in behaviour and metabolic risk markers were found between full moon ±4 d and ±10-14 d from full moon, periods that both coincide with spring tides.
“However, as we find large differences in behaviour and metabolic risk markers between full moon ±4 d and ±10–14 d from full moon, periods that both coincide with spring tides, these gravitational forces cannot explain our findings.”
Quote in the paperSubstantial claim
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The present finding is in contrast to Sjödin et al. (7), who reported that children slept 4.1 min longer at full moon compared to new moon.
“Our finding is, however, in contrast to what Sjödin et al. (7) recently reported in children, i.e., that children slept 4.1 min longer at full moon compared to new moon in a sample of Danish children aged 8–11 years.”
From Are children like werewolves? Full moon and its association with sleep and activity behaviors in an international sample of children (2016) · cites this paper as [7]
Children were not assessed through a whole lunar cycle, but only a week, which may influence the comparisons reported.
“Third, children were not assessed through a whole lunar cycle, but only a week. Although this approach has been used previously (7), it may influence the comparisons reported.”
From Are children like werewolves? Full moon and its association with sleep and activity behaviors in an international sample of children (2016) · cites this paper as [7]
The classifications of lunar phases are identical to those used in recently published papers (4-7).
“These classifications of lunar phases are identical to those used in recently published papers (4–7).”
From Are children like werewolves? Full moon and its association with sleep and activity behaviors in an international sample of children (2016) · cites this paper as [7]
Sjödin et al. observed that children (n = 795 Danish children) slept significantly longer on average (~3 min/day) around full moon and were less physically active [~4 min/day of MVPA].
“They observed that children (n = 795 Danish children) slept significantly longer on average (~3 min/day) around full moon and were less physically active [~4 min/day of moderate-to-vigorous physical activity (MVPA)].”
From Are children like werewolves? Full moon and its association with sleep and activity behaviors in an international sample of children (2016) · cites this paper as [7]
Sjödin et al. were the only one to study this issue in children and reported that variations in sleep duration and physical activity measured with accelerometry were significantly associated with the lunar cycle.
“Sjödin et al. (7) were the only one to study this issue in children and reported that variations in sleep duration and physical activity measured with accelerometry (i.e., a device detecting acceleration) were significantly associated with the lunar cycle.”
From Are children like werewolves? Full moon and its association with sleep and activity behaviors in an international sample of children (2016) · cites this paper as [7]
Cites
Establishing a standard definition for child overweight and obesity worldwide: international survey
Cole, T. J. (2000) · BMJ · doi:10.1136/bmj.320.7244.1240 · Cited by 16,500 · see citing works
Body mass index cut offs to define thinness in children and adolescents: international survey
Cole, T. J., Flegal, K. M., Nicholls, D., & Jackson, A. A. (2007) · BMJ · doi:10.1136/bmj.39238.399444.55 · Cited by 2,614 · see citing works
Activity-Based Sleep-Wake Identification: An Empirical Test of Methodological Issues
Sadeh, A., Sharkey, M., & Carskadon, M. A. (1994) · Sleep · doi:10.1093/sleep/17.3.201 · Cited by 1,487 · see citing works
The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review
Klok, M. D., Jakobsdottir, S., & Drent, M. L. (2007) · Obesity Reviews · doi:10.1111/j.1467-789x.2006.00270.x · Cited by 1,442 · see citing works
Comparison of Accelerometer Cut Points for Predicting Activity Intensity in Youth
TROST, S. G., LOPRINZI, P. D., MOORE, R., & PFEIFFER, K. A. (2011) · Medicine & Science in Sports & Exercise · doi:10.1249/mss.0b013e318206476e · Cited by 1,360 · see citing works
Validation of a self-administered instrument to assess stage of adolescent development
Morris, N. M., & Udry, J. R. (1980) · Journal of Youth and Adolescence · doi:10.1007/bf02088471 · Cited by 974 · see citing works
The basic physiology and pathophysiology of melatonin
Claustrat, B., Brun, J., & Chazot, G. (2004) · Sleep Medicine Reviews · doi:10.1016/j.smrv.2004.08.001 · Cited by 951 · see citing works
Rajaratnam, S. M., & Arendt, J. (2001) · The Lancet · doi:10.1016/s0140-6736(01)06108-6 · Cited by 711 · see citing works
Human Responses to the Geophysical Daily, Annual and Lunar Cycles
Foster, R. G., & Roenneberg, T. (2008) · Current Biology · doi:10.1016/j.cub.2008.07.003 · Cited by 410 · see citing works
Melatonin secretion and the incidence of type 2 diabetes
McMullan, C. J., Schernhammer, E. S., Rimm, E. B., Hu, F. B., & Forman, J. P. (2013) · JAMA · doi:10.1001/jama.2013.2710 · Cited by 369 · see citing works
Dela, F., Larsen, J. J., Mikines, K. J., Ploug, T., Petersen, L. N., & Galbo, H. (1995) · Diabetes · doi:10.2337/diab.44.9.1010 · Cited by 286 · see citing works
Kjeldsen, J. S., Hjorth, M. F., Andersen, R., Michaelsen, K. F., Tetens, I., Astrup, A. V., Chaput, J., & Sjödin, A. M. (2013) · International Journal of Obesity · doi:10.1038/ijo.2013.147 · Cited by 209 · see citing works
Self-citationEvidence that the Lunar Cycle Influences Human Sleep
Cajochen, C., Altanay-Ekici, S., Münch, M., Frey, S., Knoblauch, V., & Wirz-Justice, A. (2013) · Current Biology · doi:10.1016/j.cub.2013.06.029 · Cited by 182 · cited 6× · see citing works
“These classifications of lunar phases are identical to what have been used in recently published papers (4,5,19) using information from a full moon calendar (20).”
InfluentialEvaluation of HOMA and QUICKI as measures of insulin sensitivity in prepubertal children
Cutfield, W. S., Jefferies, C., Jackson, W. E., Robinson, E. M., & Hofman, P. L. (2003) · Pediatric Diabetes · doi:10.1034/j.1399-5448.2003.t01-1-00022.x · Cited by 143 · see citing works
Hjorth, M. F., Chaput, J.-P., Michaelsen, K., Astrup, A., Tetens, I., & Sjödin, A. (2013) · BMC Public Health · doi:10.1186/1471-2458-13-808 · Cited by 143 · see citing works
Self-citationAcute sleep restriction reduces insulin sensitivity in adolescent boys
Klingenberg, L., Chaput, J.-P., Holmbäck, U., Visby, T., Jennum, P., Nikolic, M., Astrup, A., & Sjödin, A. (2013) · Sleep · doi:10.5665/sleep.2816 · Cited by 124 · see citing works
Self-citationHJORTH, M. F., CHAPUT, J.-P., DAMSGAARD, C. T., DALSKOV, S.-M., MICHAELSEN, K. F., TETENS, I., & SJÖDIN, A. (2012) · Sleep and Biological Rhythms · doi:10.1111/j.1479-8425.2012.00578.x · Cited by 106 · see citing works
Caspers, H. (1984) · Marine Biology · doi:10.1007/bf00393254 · Cited by 100 · see citing works
Damsgaard, C. T., Dalskov, S., Petersen, R. A., Sørensen, L. B., Mølgaard, C., Biltoft-Jensen, A. P., Andersen, R., Thorsen, A. V., Tetens, I., Sjödin, A. M., et al. (2012) · Scandinavian Journal of Public Health · doi:10.1177/1403494812463173 · Cited by 77 · see citing works
Self-citation(2006) · Choice Reviews Online · doi:10.5860/choice.43-6516 · Cited by 71 · see citing works
Sleepless night, the moon is bright: longitudinal study of lunar phase and sleep
RÖÖSLI, M., JÜNI, P., BRAUN‐FAHRLÄNDER, C., BRINKHOF, M. W. G., LOW, N., & EGGER, M. (2006) · Journal of Sleep Research · doi:10.1111/j.1365-2869.2006.00520.x · Cited by 71 · see citing works
Lunar cycle effects on sleep and the file drawer problem
Cordi, M., Ackermann, S., Bes, F. W., Hartmann, F., Konrad, B. N., Genzel, L., Pawlowski, M., Steiger, A., Schulz, H., Rasch, B., et al. (2014) · Current Biology · doi:10.1016/j.cub.2014.05.017 · Cited by 44 · see citing works
Damsgaard, C. T., Stark, K. D., Hjorth, M. F., Biltoft-Jensen, A. P., Astrup, A. V., Michaelsen, K. F., & Lauritzen, L. (2013) · British Journal Of Nutrition · doi:10.1017/s0007114513000585 · Cited by 43 · see citing works
Self-citationHuman daily rhythms measured for one year
Binkley, S., Tome, M. B., Crawford, D., & Mosher, K. (1990) · Physiology & Behavior · doi:10.1016/0031-9384(90)90316-v · Cited by 36 · see citing works
Human sleep and cortical reactivity are influenced by lunar phase
Smith, M., Croy, I., & Persson Waye, K. (2014) · Current Biology · doi:10.1016/j.cub.2014.05.018 · Cited by 33 · see citing works
Meteorologic factors and subjective sleep continuity: a preliminary evaluation
Pandey, J., Grandner, M., Crittenden, C., Smith, M. T., & Perlis, M. L. (2005) · International Journal of Biometeorology · doi:10.1007/s00484-004-0227-1 · Cited by 28 · see citing works
Pearson, H. (2006) · Nature · doi:10.1038/news060828-13 · Cited by 2 · see citing works
Flagged first, then by citations
Research works printed but not linked: 1
- Zeitlhofer J, 2004, Is there a lunar effect on subjective and objective ratings of sleep quality?, J Sleep Res, 13, 822
Cited by
Sorted by citations
The Still Dark Side of the Moon: Molecular Mechanisms of Lunar-Controlled Rhythms and Clocks
Andreatta, G., & Tessmar-Raible, K. (2020) · Journal of Molecular Biology · doi:10.1016/j.jmb.2020.03.009 · Cited by 111 · see citing works
Moonstruck sleep: synchronization of human sleep with the moon cycle under field conditions
Casiraghi, L., Spiousas, I., Dunster, G. P., McGlothlen, K., Fernández-Duque, E., Valeggia, C., & de la Iglesia, H. O. (2021) · Science Advances · doi:10.1126/sciadv.abe0465 · Cited by 76 · see citing works
Sleep, circadian dysrhythmia, obesity and diabetes
Sridhar, G. R., & Sanjana, N. S. N. (2016) · World Journal of Diabetes · doi:10.4239/wjd.v7.i19.515 · Cited by 44 · see citing works
Dergaa, I., Fessi, M. S., Chaabane, M., Souissi, N., & Hammouda, O. (2019) · Chronobiology International · doi:10.1080/07420528.2019.1637346 · Cited by 34 · see citing works
Does lunar cycle affect biological parameters in young healthy men?
Dergaa, I., Romdhani, M., Fessi, M. S., Ben Saad, H., Varma, A., Ben Salem, A., Gadhavi, B., Chaabane, M., Souissi, N., & Hammouda, O. (2021) · Chronobiology International · doi:10.1080/07420528.2021.1897609 · Cited by 27 · see citing works
Chaput, J.-P., Weippert, M., LeBlanc, A. G., Hjorth, M. F., Michaelsen, K. F., Katzmarzyk, P. T., Tremblay, M. S., Barreira, T. V., Broyles, S. T., Fogelholm, M., et al. (2016) · Frontiers in Pediatrics · doi:10.3389/fped.2016.00024 · Cited by 19 · see citing works
Self-citation
- Authors
- Sjödin, A., Hjorth, M. F., Damsgaard, C. T., Ritz, C., Astrup, A., & Michaelsen, K. F.
- Affiliations
- University of Copenhagen (DK)
- Corresponding author
- Hjorth, M. F.
- Venue
- Clinical Obesity
- Publisher
- Wiley
- Published
- 2015-03-23
- Volume
- 5
- Issue
- 2
- Pages
- 60-66
- ISSN
- 1758-8103 (ISSN-L)
- 1758-8111
- PMC
- PMC4672692
- OpenAlex
- W1761589617
- Semantic Scholar
- 2ba7a8b5f8b5b2920cff31dd54dfeab5bf114c56
- Cited by
- 39
- References
- 27
- Citations by year
- 2026: 1 · 2025: 3 · 2024: 2 · 2023: 2 · 2022: 2 · 2021: 8 · 2020: 2 · 2019: 3 · 2018: 5 · 2017: 1 · 2016: 7 · 2015: 3
- FWCI
- 2.96
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- Locations
- Clinical Obesity (publishedVersion, cc-by-nc)
- Europe PMC (PubMed Central) (publishedVersion, cc-by-nc)
- PubMed Central (publishedVersion, cc-by-nc)
- PubMed (publishedVersion)
- Research at the University of Copenhagen (University of Copenhagen) (publishedVersion, cc-by-nc)
- Funders
- Nordea-fonden (02-2010-478 0389)
- Topics
- Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
- Health Sciences › Medicine › Physiology › Physical Activity and Health
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
- Keywords
- lunar cycle, full moon, physical activity, sleep duration, cardiometabolic risk factors, insulin resistance, ghrelin, leptin, blood pressure, children, accelerometer-measured activity, appetite-regulating hormones
- MeSH terms
- Blood Glucose, Blood Pressure, Child, Female, Humans, Insulin Resistance, Lipids, Male, Motor Activity, Periodicity, Retrospective Studies, Sleep, Moon, Leptin, Ghrelin
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-09.
Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
