An interventional study of Sleep extension in Sleep Duration, Child Obesity and Child Development, sponsored by University of Copenhagen. Recruiting at 3 sites in Denmark. Open to participants aged 6 Years to 12 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-25.
Sponsored by University of Copenhagen · Not applicable, Interventional, and Treatment
More2Sleep is a randomized, controlled, parallel trial with two groups (sleep extension vs control) including 142 school-aged children (6-12 years) who have a BMI above average, defined as age- and sex-specific BMI Z-score above zero using WHO reference standards, and habitually sleep for ≤ 9 h/night. Data will be collected before and after a 3-month sleep extension intervention, and after a 6-month follow-up (at months 0, 3, and 9). The collection of data is mainly related to the main study. However, some optional examinations will be conducted on a first come, first serve basis, consisting of substudy-I (metabolic mechanisms, n=60) and substudy-II (learning mechanisms, n=142).
The primary objective is to assess the effects of sleep extension by \~45 min/night, achieved by going to bed 60-90 min earlier, on adiposity and learning ability in school-aged children who have a BMI for age and sex above average, and sleep less than recommended for their age.
1,129 studies on the registry are indexed under Pediatric Obesity; 187 are open to participants now.
This study's planned enrollment of 142 is above the median of 100 across 870 interventional studies indexed under Pediatric Obesity.
Browse Pediatric Obesity studies →University of Copenhagen is the lead sponsor of 466 studies on the registry; 64 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The sleep extension group (n=71) will receive a behavioral intervention focusing on parents putting their children to bed earlier by 60-90 minutes. Parents will be instructed only to alter their children's daily sleeping routine, and not to directly alter their diet and physical activity habits. Children and their parents will receive a behavioral intervention consisting of 6 sessions, including both in-person and virtual sessions, which will be scheduled based on the family's availability and to accommodate practicalities.
Behavioral: Sleep extension
The control group (n=71) will follow their habitual sleeping schedule. Parents will be instructed not to alter their children's daily sleeping routine, or their diet and physical activity habits. The same number and frequency of meetings (in-person or virtual) and methods of registration of bedtime/wake-up times will be used as in the sleep extension group. These meetings will be educational in nature and focus on general well-being and informing the families about the home registrations of e.g., sleep and dietary intake.
The sleep extension group will receive a behavioral intervention focusing on parents putting their children to bed earlier by 60-90 minutes. Previous studies have found this change in daily sleeping routine to be feasible and to result in 40-45 min more actual sleep. Children and their parents will receive a behavioral intervention consisting of 6 sessions, including both in-person and virtual sessions, which will be scheduled based on the family's availability and to accommodate practicalities, e.g., potential sickness or cancellations. The first two sessions will occur at the beginning of the study. These initial sessions will focus on effective behavioral strategies to enhance sleep time, including goal setting (e.g., bedtimes and wake-up times), problem-solving and preplanning, stimulus control (i.e., sleep hygiene recommendations), and positive reinforcement. Subsequent sessions will be planned with the families to occur regularly during the 12-week intervention.
BMI Z-score
BMI (in kg/m\^2) will be calculated from weight and height (secondary outcomes), and the age- and sex-specific BMI Z-score (in units of standard deviation from the reference population mean) will be computed using international (WHO) data
Time frame: Assessed at months 0, 3 and 9
Learning ability: skill learning
Skill learning ability will be measured as motor memory assessed as 24h retention after skill practice - I.e. total within and between session effect (range: from "low" = 0 to "high" = 100, unitless)
Time frame: Assessed at months 0 and 3
Learning ability: Explicit memory
Explicit memory assessed as 24h retention after word list memory encoding - I.e. total within and between session effect. Number of correctly recalled words in a 2-minute standardized task (range: from 0 to 20)
Time frame: Assessed at months 0 and 3
Body fat percent
Body fat in % of total body mass (total fat mass divided by total body weight) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan
Time frame: Assessed at months 0, 3 and 9
Total fat mass (FM)
Body FM (in grams) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan
Time frame: Assessed at months 0, 3 and 9
Total lean mass (LM)
Body LM (in grams) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan
Time frame: Assessed at months 0, 3 and 9
Bone mineral content (BMC)
BMC (in grams) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan
Time frame: Assessed at months 0, 3 and 9
Bone mineral density (BMD)
Areal BMD (in grams/cm\^2) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan
Time frame: Assessed at months 0, 3 and 9
Dietary energy intake
Daily energy intake (in kcal/day) will be assessed with a three-day 24-hour recall interview on www.myfood24.org (daily averages will be computed)
Time frame: Assessed at months 0, 3 and 9
Dietary protein, carbohydrate, fiber, and fat intakes
Macronutrient intakes (in grams/day) will be assessed with a three-day 24-hour recall interview on www.myfood24.org (daily averages will be computed)
Time frame: Assessed at months 0, 3 and 9
Subjective hunger
Subjective level of hunger (range: from "very hungry" = 1 to "not hungry at all" = 5) in the fasting state and at 1 and 2 hours after a standardized breakfast will be measured by using an image-based visual analog scale (VAS)
Time frame: Assessed at months 0 and 3
Physical activity (PA) time: total PA and MVPA
The time (in min/day) spent being physically active regardless of intensity (total PA) and the time (in min/day) spent on moderate-to-vigorous-physical-activities (MVPA) will be measured for 7 consecutive days (daily averages will be computed) using a wrist-worn triaxial accelerometer
Time frame: Assessed at months 0, 1.5,3 and 9
Resting metabolic rate (RMR)
RMR (in kcal/day) will be measured with indirect calorimetry (canopy mode) the morning after an overnight fast (at least 8 hours)
Time frame: Assessed at months 0 and 3
Thermic effect of food (TEF)
TEF (in kcal) will be computed as the incremental area under the curve (above RMR) for postprandial energy expenditure (measured by indirect calorimetry) for 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Weight
Body mass (in kg) will be measured on a digital scale to the nearest 0.1 kg
Time frame: Assessed at months 0, 3 and 9
Height
Stature (in cm) will be measured using a wall-mounted stadiometer to the nearest 0.1 cm
Time frame: Assessed at months 0, 3 and 9
Total energy expenditure (TEE)
TEE (in kcal/day) will be measured by using the doubly labelled water method (8 urine samples over 2 weeks)
Time frame: Assessed at months 0 and 3
Cognitive functions: Sustained attention
Performance in neuropsychological assessment of sustained attention ability assessed as errors during a sustained test procedure, CANTAB test battery.
Time frame: Assessed at months 0, 3 and 9
Cognitive functions: Spatial working memory
Performance in neuropsychological assessment of spatial working memory assessed as errors and strategy during the test procedure (Cambridge Neuropsychological Test Automated Battery, Cambridge cognition, UK).
Time frame: Assessed at months 0, 3 and 9
Cognitive functions: Inhibitory control
Performance in neuropsychological assessment of inhibitory control assessed as errors during the test procedure (Modified Eriksen Flanker test, Psychology Software Tools, US) and Cambridge Neuropsychological Test Automated Battery, Cambridge cognition, UK)
Time frame: Assessed at months 0, 3 and 9
Cognitive functions: Cognitive flexibility
Performance in neuropsychological assessment of cognitive flexibility assessed as errors during the test procedure (Cambridge Neuropsychological Test Automated Battery, Cambridge cognition, UK)
Time frame: Assessed at months 0, 3 and 9
School performance: mathematics performance
Mathematics proficiency will be measured by Hogrefe math test
Time frame: Assessed at months 0, 3 and 9
School performance: reading comprehension
Danish reading proficiency will be measured by Hogrefe reading comprehension test
Time frame: Assessed at months 0, 3 and 9
Neurophysiological Measurement 1 - ERP Amplitude
EEG activity measured as the event-related potential (ERP) amplitude during the modified Eriksen Flanker Test
Time frame: Assessed at months 0 and 3
Neurophysiological Measurement 2 - Cortical activity during skill learning
Cortical activity during skill learning will be measured as EEG power
Time frame: Assessed at months 0 and 3
Neurophysiological Measurement 3 - Muscle activity during skill learning
Muscle activity during skill learning will be measured as electromyography amplitude
Time frame: Assessed at months 0 and 3
Neurophysiological Measurement 4 - corticocortical functional connectivity
Corticocortical functional connectivity will be measured as functional coupling in EEG (scale 0-1)
Time frame: Assessed at months 0 and 3
Neurophysiological Measurement 5 - corticomuscular connectivity
Corticomuscular connectivity will be measured as functional coupling between EEG and EMG during skill learning (0-1)
Time frame: Assessed at months 0 and 3
Eating window
The parents will be asked to note on a checklist when their children start and finish eating on each registration day to estimate the duration of the daily eating window.
Time frame: Assessed at months 0, 3 and 9.
Health-related quality of life: child-reported
The total summary score of health-related quality of life (from 50 to 250), and sub-scale scores (from 10 to 50) of physical well-being, psychological well-being, autonomy and parent relation, peers and social support, and school environment, will be assessed by KIDSCREEN 27 questionnaire
Time frame: Assessed at months 0, 3 and 9
Health-related quality of life: parent-reported
The Health Related Quality of Life score (from 0 to 100), Physical Health Summary score (from 0 to 100) and Psychosocial Health summary score (from 0 to 100) will be assessed by the Pediatric Quality of Life inventory (PedsQL)-Parent report (separate version for 6-7 y and 8-9 years olds)
Time frame: Assessed at months 0, 3 and 9
Mental health: parent-reported
The total difficulties score (from 0 to 40) of the Strengths and Difficulties Questionnaire, as well as sub-scale scores (from 0 to 10) of emotional symptoms, conduct problems, hyperactivity/inattention, relationship problems and prosocial behavior
Time frame: Assessed at months 0, 3 and 9
Parental Stress Scale: parent-reported
Perceived parental stress (from 18 to 90) will be assessed by the Parental Stress Scale questionnaire
Time frame: Assessed at months 0, 3 and 9
Perceived Stress Scale: child-reported
Perceived child stress score (from 1 to 39) will be assessed by the PSS-C questionnaire
Time frame: Assessed at months 0, 3 and 9
Demographics: income
Income level (stepwise increasing from level 1 to 7) will be reported by the parents on a demographics questionnaire
Time frame: Assessed at month 0
Demographics: education
Education level (stepwise increasing from level 1 to 8) will be reported by the parents on a demographics questionnaire
Time frame: Assessed at month 0
Wakefulness
Wakefulness (score from "very awake" = 1 to "sleeping" = 8) assessed by Standford Sleepiness Scale
Time frame: Assessed at months 0, 3 and 9
Handedness
Handedness preference (right or left) will be assessed by asking the children "Which hand do you use to write and draw?" do to determine dominant hand
Time frame: Assessed at month 0
Fine Motor Control
Fine motor control will be assessed by the pegboard test (score in number of pins placed correctly)
Time frame: Assessed at months 0, 3 and 9
Muscle strength
Muscular strength of the handgrip will be measured by a handgrip dynamometer (in Newton)
Time frame: Assessed at months 0, 3 and 9
Brain myelination
Indices of myelination in grey and white matter are estimated using R1 obtained from an MP2RAGE MRI-sequence
Time frame: Assessed at months 0 and 3
Brain structural connectivity and microstructure
Grey and white matter microstructure will be examined using diffusion-weighted imaging
Time frame: Assessed at months 0 and 3
Brain functional connectivity
Functional connectivity will be measured using resting-state function MRI (fMRI)
Time frame: Assessed at months 0 and 3
Vital signs: blood pressure
Systolic and diastolic blood pressure (in mmHg) will be measured at rest by using a automatic sphygmomanometer
Time frame: Assessed at months 0, 3 and 9
Cognitive functions: processing speed
Performance in neuropsychological assessment of processing speed as choice reaction time, CANTAB test battery.
Time frame: Assessed at months 0, 3 and 9
Fasting and postprandial interleukin 6 concentration
The concentration of IL6 (in ng/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial cholecystokinin concentration
The concentration of CKK (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial peptide YY concentration
The concentration of PYY (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial glucagon like peptide 1 concentration
The concentration of GLP1 (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial leptin concentration
The concentration of leptin (in ng/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial ghrelin concentration
The concentration of ghrelin (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial tumor necrosis factor alpha concentration
The concentration of TNFa (in ng/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial C-reactive protein concentration
The concentration of CRP (in mg/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial triglyceride concentration
The concentration of triglyceride (in mmol/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial total, HDL and LDL cholesterol concentrations
The concentrations of total, HDL and LDL cholesterol (in mmol/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial insulin concentration
The concentration of insulin (in pmol/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Fasting and postprandial glucose concentration
The concentration of glucose (in mmol/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast
Time frame: Assessed at months 0 and 3
Vital signs: heart rate
Heart rate (in beats per minute, bpm) will be measured at rest by using an automatic sphygmomanometer
Time frame: Assessed at months 0, 3 and 9
Vital signs: temperature
Body (skin) temperature (in degrees Celsius) will be measured telemetrically in the ear
Time frame: Assessed at months 0, 3 and 9
Sleep quality: self-reported sleep duration
Sleep duration (hour/night) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported).
Time frame: Assessed at months 0, 3 and 9
Sleep quality: self-reported latency
Latency (minutes) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported)
Time frame: Assessed at months 0, 3 and 9
Sleep quality: self-reported awakenings
Awakenings (number/night) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported).
Time frame: Assessed at months 0, 3 and 9
Sleep quality: self-reported tiredness/sleepiness
Tiredness/sleepiness during the day (yes/no) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported).
Time frame: Assessed at months 0, 3 and 9
Sleep quality and architecture: Sleep stages
Sleep stages (distribution of sleep stages in minutes and percentages of total sleep time) will be measured by polysomnography through a one night sleep period.
Time frame: Assessed at months 0 and 3
Sleep quality and architecture: sleep duration
Total sleep time (minutes) will be measured by polysomnography through a one night sleep period.
Time frame: Assessed at months 0 and 3
Sleep quality and architecture: sleep latency
Sleep latency (minutes) will be measured by polysomnography through a one night sleep period.
Time frame: Assessed at months 0 and 3
Sleep quality and architecture: awakenings
Awakenings (number) will be measured by polysomnography through a one night sleep period.
Time frame: Assessed at months 0 and 3
Sleep quality and architecture: arousals
Arousals (number per hour) will be measured by polysomnography through a one night sleep period.
Time frame: Assessed at months 0 and 3
Sleep: duration
Sleep duration (in minutes per night) will be measured by using a wrist-worn triaxial accelerometer for 7 consecutive days (the average will be computed).
Time frame: Assessed at months 0, 1.5,3 and 9
Sleep: movements
Movements (number) will be measured by using a wrist-worn triaxial accelerometer for 7 consecutive days (the average will be computed).
Time frame: Assessed at months 0, 1.5,3 and 9
Sleep: awakenings
Awakenings (number) will be measured by using a wrist-worn triaxial accelerometer for 7 consecutive days (the average will be computed).
Time frame: Assessed at months 0, 1.5,3 and 9
Brain structure: cortical thickness
Cortical thickness (mm) will be measured by a T1-weighted MR-image (MP2RAGE).
Time frame: Assessed at months 0 and 3
Brain structure: volume
Volume (mm3) will be measured by a T1-weighted MR-image (MP2RAGE).
Time frame: Assessed at months 0 and 3
Brain structure: Surface
Surface area (mm2) will be measured by a T1-weighted MR-image (MP2RAGE).
Time frame: Assessed at months 0 and 3
Brain structure: volumes of subcortical grey matter structures
Volumes (mm3) of subcortical grey matter structures will be measured by a T1-weighted MR-image (MP2RAGE).
Time frame: Assessed at months 0 and 3
Fasting concentration of peripheral blood mononuclear cells.
The concentration of isolated blood mononuclear cells will be measured in blood in fasting state.
Time frame: Assessed at months 0 and 3
Fasting concentration of sex hormones
The concentration of sex hormones will be measured in blood during fasting.
Time frame: Assessed at months 0 and 3
Puberty stage
Puberty stage will be evaluated by a standardized questionnaire completed by the parents that assesses the child's puberty stage according to the Tanner's stage classification method.
Time frame: Assessed at months 0, 3 and 9.
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