[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100658767":3},{"organization":4,"outcomesModule":7,"designInfo":22,"detailedDescription":25,"studyPopulation":26,"armGroups":27,"interventions":33,"overallOfficials":38,"centralContacts":47,"locations":53,"responsibleParty":69,"collaborators":21,"id":71,"slug":72,"hasResults":73,"nctId":74,"briefTitle":75,"officialTitle":76,"acronym":21,"eligibilityCriteria":77,"healthyVolunteers":78,"sex":79,"minAge":80,"maxAge":81,"enrollmentInfo":82,"targetDuration":21,"studyType":85,"phases":21,"briefSummary":86,"conditions":87,"keywords":90,"overallStatus":96,"whyStopped":21,"lastUpdateSubmitDate":97,"lastUpdatePostDateStruct":98,"startDateStruct":101,"completionDateStruct":103,"leadSponsor":105,"locationsCount":106},{"fullName":5,"class":6},"University of Aberdeen","OTHER",{"primaryOutcomes":8,"secondaryOutcomes":13,"otherOutcomes":21},[9],{"measure":10,"description":11,"timeFrame":12},"Change in Total Energy Expenditure Between Winter and Summer","Within-participant difference in mean daily total energy expenditure between the winter and summer measurement periods. Total energy expenditure will be measured using the doubly labelled water method and expressed in MJ\u002Fday.","Each approximately 14-day measurement period in winter and summer",[14,18],{"measure":15,"description":16,"timeFrame":17},"Change in Physical Activity Between Winter and Summer","Within-participant difference in physical activity between the winter and summer measurement periods. Physical activity will be assessed using accelerometry, including overall activity level and time spent at different activity intensities.","Continuously over each approximately 14-day measurement period in winter and summer",{"measure":19,"description":20,"timeFrame":12},"Change in Water Turnover Between Winter and Summer","Within-participant difference in mean daily water turnover between the winter and summer measurement periods. Water turnover will be estimated from isotope elimination using the doubly labelled water method.",null,{"allocation":21,"interventionModel":21,"interventionModelDescription":21,"primaryPurpose":21,"observationalModel":23,"timePerspective":24,"maskingInfo":21},"COHORT","PROSPECTIVE","The study uses a prospective repeated-measures design in which the same participants are assessed during winter and summer under free-living conditions. Healthy adults aged 18-50 years will be recruited from Aberdeen and the surrounding area. Participants will complete one approximately 14-day monitoring period in each season.\n\nDuring each study period, total energy expenditure and water turnover will be assessed using doubly labelled water. Physical activity will be monitored using an accelerometer, and personal environmental exposure will be assessed using wearable temperature sensors and GPS-based location monitoring. Anthropometry, body composition, blood pressure, heart rate, and lung function will also be measured, and dietary intake will be assessed using 24-hour dietary recalls.\n\nThe primary analyses will compare measurements within individuals between winter and summer. Associations between environmental exposure, physical activity, total energy expenditure, and water turnover will also be examined. The study is observational; seasonal and environmental exposures are not assigned by the investigators.","Healthy adult volunteers aged 18-50 years living in or near Aberdeen, Scotland. Participants will be recruited from the general adult population through open advertisement and must be available to complete both winter and summer measurement periods. Recruitment will aim for approximately balanced representation of males and females.",[28],{"label":29,"type":21,"description":30,"interventionNames":31},"Healthy Adults","Healthy adults aged 18-50 years living in or near Aberdeen, Scotland. All participants will complete two approximately 14-day free-living measurement periods, one in winter and one in summer. Seasonal and environmental exposures are observed under natural conditions and are not assigned by the investigators.",[32],"Other: Seasonal Environmental Exposure",[34],{"type":6,"name":35,"description":36,"armGroupLabels":37,"otherNames":21},"Seasonal Environmental Exposure","Participants will be observed under naturally occurring winter and summer environmental conditions. Environmental exposures of interest include personal ambient temperature, time spent outdoors, relative humidity, and daylight\u002Fsunlight conditions. Personal ambient temperature and outdoor exposure will be characterised during each approximately 14-day measurement period using wearable temperature sensors and GPS-based monitoring. Relative humidity and daylight\u002Fsunlight conditions will be characterised using regional meteorological and environmental data. These exposures are not assigned or manipulated by the investigators and will be examined in relation to total energy expenditure, water turnover, and physical activity.",[29],[39,42,45],{"name":40,"affiliation":5,"role":41},"John R Speakman","PRINCIPAL_INVESTIGATOR",{"name":43,"affiliation":5,"role":44},"Catherine Hambly","STUDY_DIRECTOR",{"name":46,"affiliation":5,"role":44},"Sharon Mitchell",[48],{"name":49,"role":50,"phone":51,"phoneExt":21,"email":52},"HUIHUI MEI","CONTACT","+447345185714","h.mei.25@abdn.ac.uk",[54],{"facility":55,"status":21,"city":56,"state":57,"zip":58,"country":59,"countryCode":60,"cosmosGeoPoint":61,"geoPoint":66,"contacts":67},"University of Aberdeen, School of Biological Sciences, Zoology Building","Aberdeen","Scotland","AB24 2TZ","United Kingdom","UK",{"type":62,"coordinates":63},"Point",[64,65],-2.09814,57.14369,{"lat":65,"lon":64},[68],{"name":49,"role":50,"phone":51,"phoneExt":21,"email":52},{"type":70,"investigatorFullName":21,"investigatorTitle":21,"investigatorAffiliation":21,"oldNameTitle":21,"oldOrganization":21},"SPONSOR","100658767","seasonal-variation-in-energy-expenditure-water-turnover-and-physical-activity-in-adults-100658767",false,"NCT07856316","Seasonal Variation in Energy Expenditure, Water Turnover, and Physical Activity in Adults","Impacts of Seasonal Environmental Variation on Energy Expenditure, Water Turnover, and Physical Activity","Inclusion Criteria:\n\nHealthy adults aged 18-50 years Body mass index (BMI) of 18.5-29.9 kg\u002Fm² Available to participate in both winter (January\u002FFebruary) and summer (July\u002FAugust) measurement periods Resident in or near Aberdeen, or spending most of the year in Scotland during the study period\n\nExclusion Criteria:\n\nAny condition limiting normal daily physical activity Engagement in high-intensity training, including professional athletes History of bariatric surgery, current weight-loss interventions, or significant recent weight change (\\>5 kg in the previous 6 months) Pregnancy, breastfeeding, planning pregnancy, irregular menstrual cycles, or menopause Any medical condition that may affect metabolism, physical activity, water balance, or study safety, including diabetes, uncontrolled thyroid disease, significant heart or kidney disease, or respiratory disease that limits normal activity Any psychiatric condition that may affect participation, daily activity, appetite, or ability to follow study procedures Use of medications or treatments that may significantly affect metabolism, appetite, body weight, or physical activity, including weight-loss medications, corticosteroids, diuretics, or stimulant medications Inability to provide informed consent Any condition judged by the investigators to compromise participant safety or data quality",true,"ALL","18 Years","50 Years",{"count":83,"type":84},30,"ESTIMATED","OBSERVATIONAL","This prospective observational study will investigate seasonal variation in total energy expenditure, water turnover, and physical activity in healthy adults living in or near Aberdeen, Scotland. Participants will complete two approximately 14-day measurement periods, one in winter and one in summer. Total energy expenditure and water turnover will be assessed using the doubly labelled water method, while physical activity and personal environmental exposure will be measured using wearable devices. The study will examine within-person differences between winter and summer and explore whether environmental factors, including ambient temperature, daylight, and sunlight exposure, are associated with changes in energy expenditure, water turnover, and physical activity.",[88,89],"Energy Expenditure","Physical Activity",[91,92,93,94,95],"Seasonal variation","Total energy expenditure","Physical activity","Ambient temperature","Water turnover","NOT_YET_RECRUITING","2026-09-23",{"date":99,"type":100},"2026-10-02","ACTUAL",{"date":102,"type":84},"2026-12",{"date":104,"type":84},"2028-04",{"name":5,"class":6},1]