The Impact of Glycemic Index on Sleep and Memory Consolidation

NCT ID: NCT05591573

Last Updated: 2024-03-12

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-12-31
• Study Completion Date: 2023-04-30

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.

Detailed Description

Few studies have examined the impact of meal composition on sleep. Most research has focused on carbohydrate intake, although reports are sporadic and confounded by the manipulation of other macronutrients. Nonetheless, the pattern of results appears to depend on the nature of the sleep variable under investigation e.g., latency, duration, or efficiency. The study will determine whether manipulating the glycemic index of a pre-bed drink influences sleep architecture, procedural and declarative memory consolidation, nocturnal glucose metabolism, and mood.

Participants will stay in the sleep laboratory for three nights, each night separated by one week (visit 1, 2, and 3). The first night is an acclimatisation night. The same procedure will be followed on all three nights, as described below.

On the morning of each visit, a continuous glucose monitor will be set up and worn until 8pm the following evening. Participants will be asked to return to the sleep laboratory at 7pm, having fasted for five hours, and asked to consume a standardised evening meal. Several mood questionnaires will be completed throughout the evening and a polysomnography will be set up. Two memory tasks will be administered at approximately 10pm. Immediately after this, participants will consume either water (night 1), or a low glycemic index or high glycemic index drink (night 2 or 3). Participants will retire to bed at approximately 11pm and woken up between 6.30am - 8am, depending on personal preference.

In the morning, the memory tasks will be administered again, as well as two mood questionnaires. Participants will be asked to wear a Pro-Diary watch throughout the day, which measures mood and hunger. At 8pm, both the continuous glucose monitor and Pro-diary watch will be collected from the participant.

Conditions

Sleep Architecture; Cognitive Function; Mood; Glucose Metabolism

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: OTHER
• Blinding Strategy: TRIPLE

Study Groups

Low glycemic index drink

Fruit drink containing low glycemic index sugar.

Group Type: EXPERIMENTAL

Low glycemic index drink

Intervention Type: DIETARY_SUPPLEMENT

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

High glycemic index drink

Fruit drink containing high glycemic index sugar.

Group Type: EXPERIMENTAL

High glycemic index drink

Intervention Type: DIETARY_SUPPLEMENT

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

Interventions

Low glycemic index drink

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

Intervention Type: DIETARY_SUPPLEMENT

High glycemic index drink

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

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• 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

Exclusion Criteria

• 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)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Swansea University

OTHER

Sponsor Role: lead

Responsible Party

Dr Hayley Young

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Hayley Young

Role: STUDY_DIRECTOR

Swansea University

Locations

Swansea University

Swansea, West Glamorgan, United Kingdom

Countries

United Kingdom

References

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.

Reference Type: DERIVED

PMID: 39854800 (View on PubMed)

Other Identifiers

SSSU

Identifier Type: -

Identifier Source: org_study_id