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NCT Number: NCT06341179

Effect of Sleep Extension on Body Weight and Learning in Children (More2Sleep)

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.

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Key information

Conditions

Sleep Duration Behavior Body Weight Child Behavior Child Development Child Obesity Dyssomnias Mental Disorders Nervous System Diseases Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Pediatric Obesity Signs and Symptoms Sleep Disorders, Intrinsic Sleep Initiation and Maintenance Disorders Sleep Wake Disorders

Age range

6 year–12 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Copenhagen, Copenhagen, Denmark

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Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age: 6-12 years old (inclusive range).
  • Weight status: having a BMI above average, defined as an age- and sex-specific BMI Z-score above zero using reference standards from the WHO.
  • Sleep duration: sleeping ≤9 h/night on the basis of sleep diaries filled in by the children's parents, based on recommendations by the American Academy of Sleep Medicine and the Sleep Health Foundation.

Exclusion criteria

  • Any genetic, neurological, endocrinological or psychiatric condition that affects growth, metabolism, eating behaviors, cognitive function, or body weight (for example: dwarfism, epilepsy, attention deficit hyperactivity disorder, head trauma, β-thalassemia, hypothyroid-ism, hyperthyroidism, type I diabetes).
  • Any sleep-related disorder (for example: obstructive sleep apnea, parasomnias, narcolepsy, restless leg syndrome).
  • Regular use of prescribed or over-the-counter medications that influence study outcomes.
  • Irregular school schedule.
  • If a child's parents live separately, the child is allowed to sleep at both households. How-ever, if one of the parents does not wish to carry out the sleep intervention and follow given instructions, then the child should only sleep at their household Friday, Saturday and/or Sunday night.
  • In the circumstance where the child does not speak or understand Danish, the child's parents do not have to speak or understand Danish, as long as both parties can speak and understand English.
  • Participation in other research studies.
  • Metal implants and claustrophobia (only for substudy-II).

Treatment and study plan

Sleep Extension

Behavioral

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.

Primary outcomes

  1. BMI Z-score

    Time frame: Assessed at months 0, 3 and 9

    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

  2. Learning ability: skill learning

    Time frame: Assessed at months 0 and 3

    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)

  3. Learning ability: Explicit memory

    Time frame: Assessed at months 0 and 3

    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)

Secondary outcomes

  1. Body fat percent

    Time frame: Assessed at months 0, 3 and 9

    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

  2. Total fat mass (FM)

    Time frame: Assessed at months 0, 3 and 9

    Body FM (in grams) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan

  3. Total lean mass (LM)

    Time frame: Assessed at months 0, 3 and 9

    Body LM (in grams) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan

  4. Bone mineral content (BMC)

    Time frame: Assessed at months 0, 3 and 9

    BMC (in grams) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan

  5. Bone mineral density (BMD)

    Time frame: Assessed at months 0, 3 and 9

    Areal BMD (in grams/cm^2) will be measured by a whole-body dual-energy X-ray absorptiometry (DXA) scan

  6. Dietary energy intake

    Time frame: Assessed at months 0, 3 and 9

    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)

  7. Dietary protein, carbohydrate, fiber, and fat intakes

    Time frame: Assessed at months 0, 3 and 9

    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)

  8. Subjective hunger

    Time frame: Assessed at months 0 and 3

    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)

  9. Physical activity (PA) time: total PA and MVPA

    Time frame: Assessed at months 0, 1.5,3 and 9

    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

  10. Resting metabolic rate (RMR)

    Time frame: Assessed at months 0 and 3

    RMR (in kcal/day) will be measured with indirect calorimetry (canopy mode) the morning after an overnight fast (at least 8 hours)

  11. Thermic effect of food (TEF)

    Time frame: Assessed at months 0 and 3

    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

  12. Weight

    Time frame: Assessed at months 0, 3 and 9

    Body mass (in kg) will be measured on a digital scale to the nearest 0.1 kg

  13. Height

    Time frame: Assessed at months 0, 3 and 9

    Stature (in cm) will be measured using a wall-mounted stadiometer to the nearest 0.1 cm

  14. Total energy expenditure (TEE)

    Time frame: Assessed at months 0 and 3

    TEE (in kcal/day) will be measured by using the doubly labelled water method (8 urine samples over 2 weeks)

  15. Cognitive functions: Sustained attention

    Time frame: Assessed at months 0, 3 and 9

    Performance in neuropsychological assessment of sustained attention ability assessed as errors during a sustained test procedure, CANTAB test battery.

  16. Cognitive functions: Spatial working memory

    Time frame: Assessed at months 0, 3 and 9

    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).

  17. Cognitive functions: Inhibitory control

    Time frame: Assessed at months 0, 3 and 9

    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)

  18. Cognitive functions: Cognitive flexibility

    Time frame: Assessed at months 0, 3 and 9

    Performance in neuropsychological assessment of cognitive flexibility assessed as errors during the test procedure (Cambridge Neuropsychological Test Automated Battery, Cambridge cognition, UK)

  19. School performance: mathematics performance

    Time frame: Assessed at months 0, 3 and 9

    Mathematics proficiency will be measured by Hogrefe math test

  20. School performance: reading comprehension

    Time frame: Assessed at months 0, 3 and 9

    Danish reading proficiency will be measured by Hogrefe reading comprehension test

  21. Neurophysiological Measurement 1 - ERP Amplitude

    Time frame: Assessed at months 0 and 3

    EEG activity measured as the event-related potential (ERP) amplitude during the modified Eriksen Flanker Test

  22. Neurophysiological Measurement 2 - Cortical activity during skill learning

    Time frame: Assessed at months 0 and 3

    Cortical activity during skill learning will be measured as EEG power

  23. Neurophysiological Measurement 3 - Muscle activity during skill learning

    Time frame: Assessed at months 0 and 3

    Muscle activity during skill learning will be measured as electromyography amplitude

  24. Neurophysiological Measurement 4 - corticocortical functional connectivity

    Time frame: Assessed at months 0 and 3

    Corticocortical functional connectivity will be measured as functional coupling in EEG (scale 0-1)

  25. Neurophysiological Measurement 5 - corticomuscular connectivity

    Time frame: Assessed at months 0 and 3

    Corticomuscular connectivity will be measured as functional coupling between EEG and EMG during skill learning (0-1)

  26. Eating window

    Time frame: Assessed at months 0, 3 and 9.

    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.

Other outcomes

  1. Health-related quality of life: child-reported

    Time frame: Assessed at months 0, 3 and 9

    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

  2. Health-related quality of life: parent-reported

    Time frame: Assessed at months 0, 3 and 9

    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)

  3. Mental health: parent-reported

    Time frame: Assessed at months 0, 3 and 9

    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

  4. Parental Stress Scale: parent-reported

    Time frame: Assessed at months 0, 3 and 9

    Perceived parental stress (from 18 to 90) will be assessed by the Parental Stress Scale questionnaire

  5. Perceived Stress Scale: child-reported

    Time frame: Assessed at months 0, 3 and 9

    Perceived child stress score (from 1 to 39) will be assessed by the PSS-C questionnaire

  6. Demographics: income

    Time frame: Assessed at month 0

    Income level (stepwise increasing from level 1 to 7) will be reported by the parents on a demographics questionnaire

  7. Demographics: education

    Time frame: Assessed at month 0

    Education level (stepwise increasing from level 1 to 8) will be reported by the parents on a demographics questionnaire

  8. Wakefulness

    Time frame: Assessed at months 0, 3 and 9

    Wakefulness (score from "very awake" = 1 to "sleeping" = 8) assessed by Standford Sleepiness Scale

  9. Handedness

    Time frame: Assessed at month 0

    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

  10. Fine Motor Control

    Time frame: Assessed at months 0, 3 and 9

    Fine motor control will be assessed by the pegboard test (score in number of pins placed correctly)

  11. Muscle strength

    Time frame: Assessed at months 0, 3 and 9

    Muscular strength of the handgrip will be measured by a handgrip dynamometer (in Newton)

  12. Brain myelination

    Time frame: Assessed at months 0 and 3

    Indices of myelination in grey and white matter are estimated using R1 obtained from an MP2RAGE MRI-sequence

  13. Brain structural connectivity and microstructure

    Time frame: Assessed at months 0 and 3

    Grey and white matter microstructure will be examined using diffusion-weighted imaging

  14. Brain functional connectivity

    Time frame: Assessed at months 0 and 3

    Functional connectivity will be measured using resting-state function MRI (fMRI)

  15. Vital signs: blood pressure

    Time frame: Assessed at months 0, 3 and 9

    Systolic and diastolic blood pressure (in mmHg) will be measured at rest by using a automatic sphygmomanometer

  16. Cognitive functions: processing speed

    Time frame: Assessed at months 0, 3 and 9

    Performance in neuropsychological assessment of processing speed as choice reaction time, CANTAB test battery.

  17. Fasting and postprandial interleukin 6 concentration

    Time frame: Assessed at months 0 and 3

    The concentration of IL6 (in ng/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  18. Fasting and postprandial cholecystokinin concentration

    Time frame: Assessed at months 0 and 3

    The concentration of CKK (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  19. Fasting and postprandial peptide YY concentration

    Time frame: Assessed at months 0 and 3

    The concentration of PYY (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  20. Fasting and postprandial glucagon like peptide 1 concentration

    Time frame: Assessed at months 0 and 3

    The concentration of GLP1 (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  21. Fasting and postprandial leptin concentration

    Time frame: Assessed at months 0 and 3

    The concentration of leptin (in ng/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  22. Fasting and postprandial ghrelin concentration

    Time frame: Assessed at months 0 and 3

    The concentration of ghrelin (in pg/mL) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  23. Fasting and postprandial tumor necrosis factor alpha concentration

    Time frame: Assessed at months 0 and 3

    The concentration of TNFa (in ng/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  24. Fasting and postprandial C-reactive protein concentration

    Time frame: Assessed at months 0 and 3

    The concentration of CRP (in mg/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  25. Fasting and postprandial triglyceride concentration

    Time frame: Assessed at months 0 and 3

    The concentration of triglyceride (in mmol/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  26. Fasting and postprandial total, HDL and LDL cholesterol concentrations

    Time frame: Assessed at months 0 and 3

    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

  27. Fasting and postprandial insulin concentration

    Time frame: Assessed at months 0 and 3

    The concentration of insulin (in pmol/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  28. Fasting and postprandial glucose concentration

    Time frame: Assessed at months 0 and 3

    The concentration of glucose (in mmol/L) will be measured in blood during fasting and at 2 hours after consuming a standardized breakfast

  29. Vital signs: heart rate

    Time frame: Assessed at months 0, 3 and 9

    Heart rate (in beats per minute, bpm) will be measured at rest by using an automatic sphygmomanometer

  30. Vital signs: temperature

    Time frame: Assessed at months 0, 3 and 9

    Body (skin) temperature (in degrees Celsius) will be measured telemetrically in the ear

  31. Sleep quality: self-reported sleep duration

    Time frame: Assessed at months 0, 3 and 9

    Sleep duration (hour/night) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported).

  32. Sleep quality: self-reported latency

    Time frame: Assessed at months 0, 3 and 9

    Latency (minutes) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported)

  33. Sleep quality: self-reported awakenings

    Time frame: Assessed at months 0, 3 and 9

    Awakenings (number/night) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported).

  34. Sleep quality: self-reported tiredness/sleepiness

    Time frame: Assessed at months 0, 3 and 9

    Tiredness/sleepiness during the day (yes/no) will be measured by the Scandinavian Sleep Questionnaire (Child and parent-reported).

  35. Sleep quality and architecture: Sleep stages

    Time frame: Assessed at months 0 and 3

    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.

  36. Sleep quality and architecture: sleep duration

    Time frame: Assessed at months 0 and 3

    Total sleep time (minutes) will be measured by polysomnography through a one night sleep period.

  37. Sleep quality and architecture: sleep latency

    Time frame: Assessed at months 0 and 3

    Sleep latency (minutes) will be measured by polysomnography through a one night sleep period.

  38. Sleep quality and architecture: awakenings

    Time frame: Assessed at months 0 and 3

    Awakenings (number) will be measured by polysomnography through a one night sleep period.

  39. Sleep quality and architecture: arousals

    Time frame: Assessed at months 0 and 3

    Arousals (number per hour) will be measured by polysomnography through a one night sleep period.

  40. Sleep: duration

    Time frame: Assessed at months 0, 1.5,3 and 9

    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).

  41. Sleep: movements

    Time frame: Assessed at months 0, 1.5,3 and 9

    Movements (number) will be measured by using a wrist-worn triaxial accelerometer for 7 consecutive days (the average will be computed).

  42. Sleep: awakenings

    Time frame: Assessed at months 0, 1.5,3 and 9

    Awakenings (number) will be measured by using a wrist-worn triaxial accelerometer for 7 consecutive days (the average will be computed).

  43. Brain structure: cortical thickness

    Time frame: Assessed at months 0 and 3

    Cortical thickness (mm) will be measured by a T1-weighted MR-image (MP2RAGE).

  44. Brain structure: volume

    Time frame: Assessed at months 0 and 3

    Volume (mm3) will be measured by a T1-weighted MR-image (MP2RAGE).

  45. Brain structure: Surface

    Time frame: Assessed at months 0 and 3

    Surface area (mm2) will be measured by a T1-weighted MR-image (MP2RAGE).

  46. Brain structure: volumes of subcortical grey matter structures

    Time frame: Assessed at months 0 and 3

    Volumes (mm3) of subcortical grey matter structures will be measured by a T1-weighted MR-image (MP2RAGE).

  47. Fasting concentration of peripheral blood mononuclear cells.

    Time frame: Assessed at months 0 and 3

    The concentration of isolated blood mononuclear cells will be measured in blood in fasting state.

  48. Fasting concentration of sex hormones

    Time frame: Assessed at months 0 and 3

    The concentration of sex hormones will be measured in blood during fasting.

  49. Puberty stage

    Time frame: Assessed at months 0, 3 and 9.

    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.

Study contacts

Contact information is provided by the study sponsor or research team.

Eva Leedo-Townend, MSc

CONTACT

[email protected]

+45 35 33 35 68

Faidon Magkos, PhD

CONTACT

[email protected]

+45 35 33 36 71

Sponsors and collaborators

Lead sponsor

University of Copenhagen

Other

Collaborators

  • Center for Obesity Research & Education, Temple University
  • Danish Research Centre for Magnetic Resonance
  • Faculty of Health, Medicine and Life Sciences, Maastricht University
  • Novo Nordisk Foundation (NNF)
  • University of Southern Denmark

Registry information

Official study title

A Randomized Controlled Trial of Sleep Extension to Regulate Body Weight and Improve Learning in School-aged Children

Acronym: More2Sleep

Important dates

Study start
2024
Primary completion
2027
Study completion
2028
First posted
Apr 2, 2024
Registry last updated
Nov 25, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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