{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,20]],"date-time":"2026-10-20T18:56:14Z","timestamp":1792522574589,"version":"4.5.0"},"reference-count":57,"publisher":"Public Library of Science (PLoS)","issue":"10","license":[{"start":{"date-parts":[[2021,10,22]],"date-time":"2021-10-22T00:00:00Z","timestamp":1634860800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["26293452 and 20K21712"],"award-info":[{"award-number":["26293452 and 20K21712"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\"><jats:title>Background<\/jats:title><jats:p>Night shift workers might not eat due to their busy schedules during the night shift. However, food may not only satisfy hunger, but also affect performance and errors. The aim of this study was to clarify the effect of a snack on performance and errors during 2-day, 16-h, simulated night shifts.<\/jats:p><\/jats:sec><jats:sec id=\"sec002\"><jats:title>Methods<\/jats:title><jats:p>A randomized, repeated-measure, crossover study was performed to investigate subjective and cognitive performance in 15 healthy female adults (mean age, 21.7 years) after they consumed a snack (352 kcal) during a simulated night shift (16:00 to 09:00) from October to November 2018. The participants were kept awake from waking up in the morning to the next day at 09:00. Subjects were tested for performance on the Uchida-Kraepelin test, as well as for subjective feeling, body temperature, psychomotor vigilance test, and heart rate variability, before and after they consumed the snack. One day before the experiment, all participants wore an actigraphy monitoring device to determine their sleep state.<\/jats:p><\/jats:sec><jats:sec id=\"sec003\"><jats:title>Results<\/jats:title><jats:p>There was no difference between having (Snack condition) and not having (Skipping condition) the snack in sleep states the day before the experiment. On the day of the experiment, between 16:00 and 09:00, subjective sleepiness, fatigue, and body temperature were not different between the two conditions. Subjects maintained performance on the Uchida-Kraepelin test and showed a significant improvement in false starts on the psychomotor vigilance test, the primary outcome measure, in the Snack condition compared with the Skipping condition. The Snack condition was also associated with decreased high-frequency power, a decreased low-frequency power\/high-frequency power ratio, and increased heart rate in the vagally mediated heart rate variability indices, which may reflect a higher ability to modulate cognitive and behavioral processes.<\/jats:p><\/jats:sec><jats:sec id=\"sec004\"><jats:title>Conclusions<\/jats:title><jats:p>These results suggest that providing a snack to shift workers during night shifts might improve work safety and efficiency.<\/jats:p><\/jats:sec>","DOI":"10.1371\/journal.pone.0258569","type":"journal-article","created":{"date-parts":[[2021,10,22]],"date-time":"2021-10-22T22:01:37Z","timestamp":1634940097000},"page":"e0258569","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":12,"title":["Effects of a snack on performance and errors during a simulated 16-h night shift: A randomized, crossover-controlled, pilot study"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1157-032X","authenticated-orcid":true,"given":"Sanae","family":"Oriyama","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kotomi","family":"Yamashita","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,10,22]]},"reference":[{"key":"pone.0258569.ref001","doi-asserted-by":"crossref","first-page":"273","DOI":"10.7888\/juoeh.36.273","article-title":"Estimate of the number of night shift workers in Japan","volume":"36","author":"T Kubo","year":"2014","journal-title":"J UOEH"},{"key":"pone.0258569.ref002","unstructured":"The Japan Institute for Labour Policy and Training, https:\/\/www.jil.go.jil.go.jp\/Kokunai\/topics\/mm\/20181114.html. [Cited 2019 Oct 28] (in Japanese)."},{"key":"pone.0258569.ref003","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1093\/sleep\/11.1.17","article-title":"Sleepiness as a consequence of shift work","volume":"11","author":"T Akerstedt","year":"1988","journal-title":"Sleep"},{"key":"pone.0258569.ref004","doi-asserted-by":"crossref","first-page":"1801","DOI":"10.1093\/sleep\/30.12.1801","article-title":"The relationship between nurse work schedules, sleep duration, and drowsy driving.","volume":"30","author":"LD Scott","year":"2007","journal-title":"Sleep"},{"key":"pone.0258569.ref005","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1002\/ajim.20307","article-title":"Modeling the impact of the components of long work hours on injuries and \u201caccidents\u201d","volume":"49","author":"S Folkard","year":"2006","journal-title":"Am J Ind Med"},{"key":"pone.0258569.ref006","doi-asserted-by":"crossref","first-page":"15","DOI":"10.2174\/1875934301609010015","article-title":"Long working hours and shift work as risk factors for occupational injury","volume":"9","author":"S Salminen","year":"2016","journal-title":"Ergon Open J"},{"key":"pone.0258569.ref007","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1177\/0748730406293889","article-title":"Properties, entrainment and physiological functions of mammalian peripheral oscillators","volume":"21","author":"M Stratmann","year":"2006","journal-title":"J Bio Rhythms"},{"key":"pone.0258569.ref008","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1007\/s00335-016-9639-6","article-title":"Reciprocal interactions between circadian clocks and aging","volume":"27","author":"G Banks","year":"2016","journal-title":"Mamm Genome"},{"key":"pone.0258569.ref009","first-page":"49","article-title":"Shift length as a determinant of retrospective on-shift alertness","volume":"24","author":"P Tucker","year":"1998","journal-title":"Scand J Work Environ Health"},{"key":"pone.0258569.ref010","doi-asserted-by":"crossref","first-page":"457","DOI":"10.3109\/07420529609020916","article-title":"Focus group evaluation of night nurse shiftwork, difficulties and coping strategies","volume":"13","author":"RD Novak","year":"1996","journal-title":"Chronobiol Int"},{"key":"pone.0258569.ref011","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1111\/j.2044-8295.1986.tb02204.x","article-title":"Acute effects of meals, noise and nightwork","volume":"77","author":"A Smith","year":"1986","journal-title":"Br J Psychol"},{"key":"pone.0258569.ref012","doi-asserted-by":"crossref","first-page":"1352","DOI":"10.3390\/nu11061352","article-title":"Subjective hunger, gastric upset, and sleepiness in response to altered meal timing during simulated shiftwork","volume":"11","author":"CC Gupta","year":"2019","journal-title":"Nutrients"},{"key":"pone.0258569.ref013","doi-asserted-by":"crossref","first-page":"87","DOI":"10.4992\/jjpsy.57.87","article-title":"The results of investigation by the Japanese version of Morningness-Eveningness Questionnaire.","volume":"57","author":"K Ishihara","year":"1986","journal-title":"Shinrigaku Kenkyu"},{"key":"pone.0258569.ref014","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1016\/j.sleep.2006.09.011","article-title":"Circadian rhythms, sleep, and the menstrual cycle","volume":"8","author":"FC Baker","year":"2007","journal-title":"Sleep Med"},{"key":"pone.0258569.ref015","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1093\/ajcn\/36.4.611","article-title":"Menstrual cycle and basal metabolic rate in women","volume":"36","author":"SJ Solomon","year":"1982","journal-title":"Am J Clin Nutr"},{"key":"pone.0258569.ref016","doi-asserted-by":"crossref","first-page":"175","DOI":"10.3758\/BF03193146","article-title":"G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences","volume":"39","author":"F Faul","year":"2007","journal-title":"Behav Res Methods"},{"issue":"Suppl 1","key":"pone.0258569.ref017","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1111\/obr.12503","article-title":"Role of sleep and circadian disruption on energy expenditure and in metabolic predisposition to human obesity and metabolic disease","volume":"18","author":"AW Mchill","year":"2017","journal-title":"Obes Rev"},{"key":"pone.0258569.ref018","first-page":"17","article-title":"Optimal thermal conditions during night sleep in summer","volume":"11","author":"Y Kawashima","year":"2004","journal-title":"J Human and Living Environment"},{"key":"pone.0258569.ref019","doi-asserted-by":"crossref","first-page":"55","DOI":"10.5271\/sjweh.1428","article-title":"Effect of masking on circadian adjustment and interindividual differences on a rapidly rotating shift schedule","volume":"20","author":"M H\u00e4rm\u00e4","year":"1994","journal-title":"Scand J Environ Health"},{"key":"pone.0258569.ref020","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1007\/s00424-011-1042-2","article-title":"Sleep, vigilance, and thermosensitivity","volume":"463","author":"N Romeijn","year":"2012","journal-title":"Pflugers Archiv"},{"key":"pone.0258569.ref021","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1046\/j.1365-2869.2002.00309.x","article-title":"The impact of a nap opportunity during the night shift on the performance and alertness of 12-h shift workers.","volume":"11","author":"MT Purnell","year":"2002","journal-title":"J Sleep Res"},{"key":"pone.0258569.ref022","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/0165-1781(89)90013-9","article-title":"A visual analog scale technique to measure global vigor and affect","volume":"27","author":"TH Monk","year":"1989","journal-title":"Psychiatry Res"},{"key":"pone.0258569.ref023","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1186\/1751-0759-3-5","article-title":"The effectiveness of the Uchida-Kreapelin test for psychological stress an analysis of plasma and salivary stress substances","volume":"3","author":"K Sugimoto","year":"2009","journal-title":"BioPsychoSocial Med"},{"key":"pone.0258569.ref024","doi-asserted-by":"crossref","first-page":"1575","DOI":"10.5665\/sleep.2214","article-title":"A combined field and laboratory design for assessing the impact of night shift work on police officer operational performance","volume":"35","author":"LB Waggoner","year":"2012","journal-title":"Sleep"},{"key":"pone.0258569.ref025","doi-asserted-by":"crossref","first-page":"1379","DOI":"10.1080\/07420520601067931","article-title":"Can a shorter psychomotor vigilance task be used as a reasonable substitute for the ten-minute psychomotor vigilance task?","volume":"23","author":"GD Roach","year":"2006","journal-title":"Chronobiol Int."},{"key":"pone.0258569.ref026","doi-asserted-by":"crossref","first-page":"193","DOI":"10.5665\/sleep.1620","article-title":"An adaptive-duration version of the PVT accurately tracks changes in psychomotor vigilance induced by sleep restriction","volume":"35","author":"M Basner","year":"2012","journal-title":"Sleep"},{"issue":"7","key":"pone.0258569.ref027","doi-asserted-by":"crossref","first-page":"e0219087","DOI":"10.1371\/journal.pone.0219087","article-title":"Decreased psychomotor vigilance of female shift workers after working night shifts","volume":"14","author":"T Behrens","year":"2019","journal-title":"PLoS ONE"},{"key":"pone.0258569.ref028","doi-asserted-by":"crossref","first-page":"171","DOI":"10.5271\/sjweh.3197","article-title":"Heart rate variability and endothelial function after sleep deprivation and recovery sleep among male shift and non-shift workers","volume":"38","author":"SM Wehrens","year":"2012","journal-title":"Scand J Work Environ Health"},{"key":"pone.0258569.ref029","first-page":"245","article-title":"Power spectral analysis of heart rate variability: a noninvasive signature of cardiac autonomic function","volume":"21","author":"MV Kamath","year":"1993","journal-title":"Crit Rev Biomed Eng"},{"key":"pone.0258569.ref030","doi-asserted-by":"crossref","first-page":"1441","DOI":"10.1161\/01.CIR.95.6.1441","article-title":"Relationship between spectral components of cardiovascular variabilities and direct measures of muscle sympathetic nerve activity in humans","volume":"95","author":"M Pagani","year":"1997","journal-title":"Circulation"},{"key":"pone.0258569.ref031","doi-asserted-by":"crossref","first-page":"67","DOI":"10.2478\/v10013-010-0007-7","article-title":"Estimating mental fatigue based on electroencephalogram and heart rate variability","volume":"16","author":"C Zhang","year":"2010","journal-title":"Pol J Med Phys Eng"},{"key":"pone.0258569.ref032","first-page":"147","article-title":"Dealing with inter-individual differences in the temporal dynamics of fatigue and performance: importance and techniques","volume":"75","author":"HP Van Dongen","year":"2004","journal-title":"Aviat Space Environ Med"},{"key":"pone.0258569.ref033","doi-asserted-by":"crossref","first-page":"391","DOI":"10.1051\/rnd:19960405","article-title":"Thermic effect of food and sympathetic nervous system activity in humans","volume":"36","author":"L Tappy","year":"1996","journal-title":"Reorod Nutr Dev"},{"key":"pone.0258569.ref034","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1093\/occmed\/kqg046","article-title":"Shift work and disturbed sleep\/wakefulness","volume":"53","author":"T Akerstedt","year":"2003","journal-title":"Occup Med"},{"key":"pone.0258569.ref035","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1539\/joh.17-0070-OA","article-title":"The effects of nighttime napping on sleep, sleep inertia, and performance during simulated 16 h night work: a pilot study","volume":"60","author":"S Oriyama","year":"2018","journal-title":"J Occup Health"},{"key":"pone.0258569.ref036","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1080\/07420528.2016.1237520","article-title":"It\u2019s not just what you eat but when: the impact of eating a meal during simulated shift work on driving performance","volume":"34","author":"CC Gupta","year":"2017","journal-title":"Chronobiol Int"},{"key":"pone.0258569.ref037","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.aap.2012.09.033","article-title":"Sleepy driving on the real road and in the simulator-A comparison","volume":"50","author":"D Hallvig","year":"2013","journal-title":"Accid Anal Prev"},{"key":"pone.0258569.ref038","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1016\/j.bandc.2012.12.002","article-title":"Effects of chewing on cognitive processing speed","volume":"81","author":"Y Hirano","year":"2013","journal-title":"Brain Cogn"},{"key":"pone.0258569.ref039","doi-asserted-by":"crossref","first-page":"695","DOI":"10.1016\/j.physbeh.2003.12.004","article-title":"Circadian and wake-dependent modulation of fastest and slowest reaction times during the psychomotor vigilance task","volume":"80","author":"P Graw","year":"2004","journal-title":"Physiol Behav"},{"key":"pone.0258569.ref040","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1093\/sleep\/26.2.117","article-title":"The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation","volume":"26","author":"HP Van Dongen","year":"2003","journal-title":"Sleep"},{"key":"pone.0258569.ref041","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1037\/a0018883","article-title":"A meta-analysis of the impact of short-term sleep deprivation on cognitive variables","volume":"136","author":"J Lim","year":"2010","journal-title":"Psychol Bull"},{"key":"pone.0258569.ref042","doi-asserted-by":"crossref","first-page":"1003","DOI":"10.1080\/07420528.2017.1335318","article-title":"Timing of food intake during simulated night shift impacts glucose metabolism: A controlled study","volume":"34","author":"CL Grant","year":"2017","journal-title":"Chronobiol Int"},{"key":"pone.0258569.ref043","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1016\/j.clnu.2017.11.010","article-title":"Effect of meal timing on postprandial glucose responses to low glycemic index meal: a crossover trial in healthy volunteers","volume":"38","author":"GKW Leung","year":"2019","journal-title":"Clin Nutr"},{"key":"pone.0258569.ref044","doi-asserted-by":"crossref","first-page":"1665","DOI":"10.1016\/j.amjcard.2011.07.028","article-title":"Comparison of coronary microcirculation in female nurses after day time versus night time shift","volume":"108","author":"T Kubo","year":"2011","journal-title":"Am J Cardiol"},{"key":"pone.0258569.ref045","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1080\/02678379008256983","article-title":"Do eating and drinking habits interact with work schedule variables?","volume":"4","author":"D Tepas","year":"1990","journal-title":"Work & Stress"},{"key":"pone.0258569.ref046","first-page":"716","article-title":"Roles of circadian rhythmicity and sleep in human glucose regulation","volume":"18","author":"E Van Cauter","year":"1997","journal-title":"Endocr Rev"},{"key":"pone.0258569.ref047","doi-asserted-by":"crossref","first-page":"1021","DOI":"10.1016\/S0899-9007(00)00450-0","article-title":"Macronutrients and mental performance.","volume":"16","author":"L Dye","year":"2000","journal-title":"Nutrition"},{"key":"pone.0258569.ref048","doi-asserted-by":"crossref","first-page":"1088","DOI":"10.1016\/j.physbeh.2011.11.025","article-title":"\u2018Post-lunch\u2019 sleepiness during prolonged, monotonous driving-effects of meal size","volume":"105","author":"LA Reyner","year":"2012","journal-title":"Physiol Behav"},{"key":"pone.0258569.ref049","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1152\/jappl.1998.84.2.507","article-title":"Effects of meals on objective and subjective measures of daytime sleepiness","volume":"84","author":"AS Wells","year":"1998","journal-title":"J Appl Physiol"},{"key":"pone.0258569.ref050","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1159\/000118920","article-title":"Effects of breakfast and caffeine on performance and mood in the late morning and after lunch.","volume":"26","author":"AP Smith","year":"1992","journal-title":"Neuropsychobiology"},{"key":"pone.0258569.ref051","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1016\/j.physbeh.2007.12.020","article-title":"Meal-induced activation of the sympathetic nervous system and its cardiovascular and thermogenic effects in man","volume":"94","author":"MA Van Baak","year":"2008","journal-title":"Physiol Behav"},{"key":"pone.0258569.ref052","doi-asserted-by":"crossref","first-page":"182","DOI":"10.1002\/ajim.20204","article-title":"Job strain and autonomic indices of cardiovascular disease risk","volume":"48","author":"SM Collins","year":"2005","journal-title":"Am J Ind Med"},{"key":"pone.0258569.ref053","doi-asserted-by":"crossref","first-page":"552","DOI":"10.1111\/j.1365-2869.2010.00844.x","article-title":"Leptin and hunger levels in young healthy adults after one night of sleep loss","volume":"19","author":"S Pejovic","year":"2010","journal-title":"J Sleep Res"},{"key":"pone.0258569.ref054","first-page":"20","article-title":"Investigation of factors influencing fatigue in hospital nurses","volume":"12","author":"Y Ohashi","year":"2010","journal-title":"J Jpn Soc Nurs Health Care"},{"key":"pone.0258569.ref055","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1177\/1937586717729349","article-title":"Alert workplace from healthcare workers\u2019 perspective: Behavioral and environment strategies to improve vigilance and alertness in healthcare settings","volume":"11","author":"R Saqah Zadeh","year":"2018","journal-title":"HERD"},{"key":"pone.0258569.ref056","doi-asserted-by":"crossref","first-page":"2980","DOI":"10.3390\/nu11122980","article-title":"Eating jet lag a marker of the variability in meal timing and its association with body mass index","volume":"11","author":"MF Zer\u00f3n-Rugerio","year":"2019","journal-title":"Nutrients"},{"key":"pone.0258569.ref057","doi-asserted-by":"crossref","first-page":"368","DOI":"10.1002\/1348-9585.12063","article-title":"The effects of a 120-minute nap on sleepiness, fatigue, and performance during 16-hour night shifts: a pilot study","volume":"61","author":"S Oriyama","year":"2019","journal-title":"J Occup Health"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0258569","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,1,13]],"date-time":"2023-01-13T12:36:43Z","timestamp":1673613403000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0258569"}},"subtitle":[],"editor":[{"given":"Henrik","family":"Oster","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,10,22]]},"references-count":57,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2021,10,22]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0258569","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,10,22]]}}}