The Impact of Glycemic Index on Sleep and Memory Consolidation

NCT05591573 | Completed

• 1 other identifier: SSSU
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The study will test whether the consumption of a low versus a high glycemic index pre-bed drink influences sleep architecture, memory consolidation, nocturnal glucose metabolism, and mood.

Conditions

Sleep Architecture; Cognitive Function; Mood; Glucose Metabolism

Outcome Measures

Primary Outcomes (7)

• Sleep onset latency (polysomnography)

  Onset of sleep from the time the lights are turned off.

  Bedtime (approx. 11.00pm) to wake time (approx 7.30am)

• Total sleep time (polysomnography)

  The total number of hours of sleep.

  Bedtime (approx. 11.00pm) to wake time (approx 7.30am)

• Wake after sleep onset (polysomnography)

  Hours of wake time after three epochs of sleep have occurred.

  Bedtime (approx. 11.00pm) to wake time (approx 7.30am)

• Sleep efficiency (polysomnography)

  Total sleep time divided by the time from lights out until awakening in the morning.

  Bedtime (approx. 11.00pm) to wake time (approx 7.30am)

• Sleep stages (polysomnography)

  Time spent in each sleep stage.

  Bedtime (approx. 11.00pm) to wake time (approx 7.30am)

• Arousal index (polysomnography)

  Number of arousals throughout the night.

  Bedtime (approx. 11.00pm) to wake time (approx 7.30am)

• Leeds Sleep Evaluation Questionnaire

  Subjective assessment of sleep quality. Scores range from 0 to 30. Higher scores indicate poorer sleep quality.

  Administered 10 - 20 minutes after waking up in the morning,

Secondary Outcomes (7)

• Glucose response (continuous glucose monitor)

  25 hours during night 2 and night 3 (weeks 2 and 3)

• Finger tapping task (procedural memory)

  Completed at 10pm, and between 6.30 - 8am the following morning, on night 2 and night 3 (week 2 and 3).

• Story recall task (declarative memory)

  Completed at 10pm, and between 6.30 - 8am the following morning, on night 2 and night 3 (week 2 and 3).

• Epworth Sleepiness Scale

  Administered at 8pm on the evening after night 2 and night 3 (week 2 and 3).

• Mood and hunger

  Completed five times throughout the evening and twice in the morning (immediately after waking up and 20-30 minutes later) on night 2 and night 3 (week 2 and 3). .

Study Arms (2)

Low glycemic index drink

EXPERIMENTAL

Fruit drink containing low glycemic index sugar.

Dietary Supplement: Low glycemic index drink

High glycemic index drink

EXPERIMENTAL

Fruit drink containing high glycemic index sugar.

Dietary Supplement: High glycemic index drink

Interventions

Low glycemic index drink DIETARY_SUPPLEMENT

Fruit flavoured drink with low glycemic index sugar (300 ml)

Low glycemic index drink

High glycemic index drink DIETARY_SUPPLEMENT

Fruit flavoured drink with high glycemic index sugar (300 ml)

High glycemic index drink

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male (given that the menstrual cycle may influence sleep polysomnography)
• Good health
• Not taking any medication known to effect sleep or metabolism
• Normal sleep duration (i.e. between 6.5 - 9 hours of sleep per night)
• A sleep efficiency score above 80% (Pittsburg Sleep Quality Index)
• Normal sleep schedule (i.e. fall asleep between 10pm and 12pm)
• No difficulty sleeping in new places

You may not qualify if:

• Diagnosis of any physical or mental disorder e.g. diabetes, cardiovascular disorders, gastrointestinal disorders, sleep problems, epilepsy, or mood disorders
• Unhealthy weight (BMI over 30)
• Drink more than 300mg of caffeine per day (3 - 4 standard sized 8-oz cups)
• Work nights or shifts
• Smoke/vape
• Regularly drink alcohol (\>3 glasses per day)
• Used recreational drugs within the last 6 months
• Take part in \>3 hours of vigorous exercise per week
• Any known food allergies or intolerances
• Nocturnal eating or regular consumption of alcohol before bed (assessed by the Meal Pattern Questionnaire)

Sponsors & Collaborators

• Swansea University: lead

Study Sites (1)

Swansea University

Swansea, West Glamorgan, SA2 8PP, United Kingdom

Location

Related Publications (1)

• Gaylor CM, Brennan A, Blagrove M, Tulip C, Bloxham A, Williams S, Tucker R, Benton D, Young HA. Low and high glycemic index drinks differentially affect sleep polysomnography and memory consolidation: A randomized controlled trial. Nutr Res. 2025 Feb;134:49-59. doi: 10.1016/j.nutres.2024.11.012. Epub 2024 Dec 4.

  PMID: 39854800 DERIVED

Study Officials

• Hayley Young

  Swansea University

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: To ensure blinding of participants and researchers, a randomisation list will be produced using Statistical Package for the Social Sciences (SPSS) software by an employee of Swansea University, who is not actively involved in the study. Blinding will be maintained by the use of encoded beverages to ensure participants, researchers, and the data analysers are unaware of the intervention. The blind will be broken only after statistical analysis of the data is complete.
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: In a randomized, double-blind, and counterbalanced order (AB/BA), participants will receive either a high glycemic index or low glycemic index pre-bed drink. After a 1-week washout period, participants will consume the alternate drink.

Study Record Dates

• First Submitted: July 15, 2022
• First Posted: October 24, 2022
• Study Start: December 31, 2022
• Primary Completion: April 30, 2023
• Study Completion: April 30, 2023
• Last Updated: March 12, 2024

Record last verified: 2024-03

Locations

GB (1)