Effects of Bedtime Snack Composition on Overnight Glucose in Children and Adolescents With Type 1 Diabetes
August 20, 2026 updated by: Didem Güneş Kaya
Bedtime Snack Composition and Overnight Glycemic Profiles in Children and Adolescents With Type 1 Diabetes Using Multiple Daily Injections: A Randomized Crossover Study
This study compared four types of bedtime snacks in children and adolescents with type 1 diabetes treated with multiple daily insulin injections. The aim was to determine whether bedtime snack nutrient composition affects overnight glucose levels.
Participants received four different bedtime snacks: carbohydrate alone, carbohydrate with protein, carbohydrate with fat, and carbohydrate with fiber. The order of the four snack types was randomly assigned. Each snack type was consumed at 9:00 PM for three consecutive nights without an additional insulin dose for the snack. All participants received all four snack types during the study.
Overnight glucose levels were measured from 9:00 PM to 9:00 AM using a blinded continuous glucose monitoring system. The primary outcome was the percentage of time glucose levels remained between 70 and 180 mg/dL during the overnight period. Secondary outcomes included measures of hypoglycemia, hyperglycemia, glucose variability, and changes in glucose levels during different periods of the night.
Study Overview
Status
Completed
Conditions
Study Type
Interventional
Enrollment (Actual)
20
Phase
- Not Applicable
Contacts and Locations
This section provides the contact details for those conducting the study, and information on where this study is being conducted.
Study Locations
-
-
Fatih
-
Istanbul, Fatih, Turkey (Türkiye), 34098
- Istanbul University Cerrahpasa-Cerrahpasa Faculty of Medicine
-
-
Participation Criteria
Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.
Eligibility Criteria
Ages Eligible for Study
- Child
- Adult
Accepts Healthy Volunteers
No
Description
Inclusion Criteria:
Age 6-18 years Diagnosis of type 1 diabetes for more than 1 year Completion of the remission period Treatment with multiple daily insulin injections Completion of all three stages of carbohydrate-counting education Ability to perform capillary blood glucose monitoring at least four times daily Total daily insulin dose >0.5 U/kg/day Mean HbA1c <9.6% during the preceding 3 months
Exclusion Criteria:
Insulin pump or sensor-augmented pump therapy Incomplete carbohydrate-counting education Impaired awareness of hypoglycemia Intestinal malabsorption Delayed gastric emptying Celiac disease or any other condition requiring dietary restriction Cystic fibrosis or other gastrointestinal disorders Diabetes-related chronic complications Physical or mental disability limiting adherence to study procedures Eating behavior disorders Active infection
Study Plan
This section provides details of the study plan, including how the study is designed and what the study is measuring.
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: Randomized
- Interventional Model: Crossover Assignment
- Masking: None (Open Label)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
|
Experimental: Sequence 1: CHO First
Participants received the four bedtime snack interventions in the following order: CHO, CHO+PRO, CHO+FAT, and CHO+FIB.
|
Participants consumed an apple as a carbohydrate-only bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed a high-protein fresh cheese bedtime snack containing carbohydrate and protein at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed an apple with nuts as a carbohydrate-plus-fat bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed rye crispbread as a carbohydrate-plus-fiber bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
|
|
Experimental: Sequence 2: CHO+PRO First
Participants received the four bedtime snack interventions in the following order: CHO+PRO, CHO+FAT, CHO+FIB, and CHO.
|
Participants consumed an apple as a carbohydrate-only bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed a high-protein fresh cheese bedtime snack containing carbohydrate and protein at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed an apple with nuts as a carbohydrate-plus-fat bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed rye crispbread as a carbohydrate-plus-fiber bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
|
|
Experimental: Sequence 3: CHO+FAT First
Participants received the four bedtime snack interventions in the following order: CHO+FAT, CHO+FIB, CHO, and CHO+PRO.
|
Participants consumed an apple as a carbohydrate-only bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed a high-protein fresh cheese bedtime snack containing carbohydrate and protein at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed an apple with nuts as a carbohydrate-plus-fat bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed rye crispbread as a carbohydrate-plus-fiber bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
|
|
Experimental: Sequence 4: CHO+FIB First
Participants received the four bedtime snack interventions in the following order: CHO+FIB, CHO, CHO+PRO, and CHO+FAT.
|
Participants consumed an apple as a carbohydrate-only bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed a high-protein fresh cheese bedtime snack containing carbohydrate and protein at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed an apple with nuts as a carbohydrate-plus-fat bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
Participants consumed rye crispbread as a carbohydrate-plus-fiber bedtime snack at 21:00.
The snack was consumed within 10 minutes, and no additional bolus insulin was administered for the snack.
This intervention was followed for three consecutive nights.
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Overnight Time in Range (70-180 mg/dL)
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Percentage of continuous glucose monitoring (CGM) readings within the target glucose range of 70-180 mg/dL during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Mean Overnight Sensor Glucose
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Mean continuous glucose monitoring (CGM) glucose concentration during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Percentage of Overnight Time in Tight Range (70-140 mg/dL)vernight Sensor Glucose
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Percentage of CGM readings within the glucose range of 70-140 mg/dL during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Percentage of Overnight Time Below Range (<70 mg/dL)
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Percentage of CGM readings below 70 mg/dL during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Percentage of Overnight Time Below Range (<54 mg/dL)
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Percentage of CGM readings below 54 mg/dL during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Percentage of Overnight Time Above Range (>180 mg/dL)
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Percentage of CGM readings above 180 mg/dL during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Percentage of Overnight Time Above Range (>250 mg/dL)
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Percentage of CGM readings above 250 mg/dL during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Coefficient of Variation of Overnight Sensor Glucose
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Coefficient of variation of CGM glucose values during the overnight period, expressed as a percentage
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Peak Overnight Sensor Glucose
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Highest CGM glucose concentration recorded during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Nadir Overnight Sensor Glucose
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Lowest CGM glucose concentration recorded during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Peak-to-Nadir Overnight Glucose Amplitude
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Difference between the highest and lowest CGM glucose concentrations during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Incremental Area Under the Overnight Glucose Curve
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Incremental area under the CGM glucose curve during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Number of Overnight Hypoglycemic Events
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Number of hypoglycemic events occurring during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
|
Number of Overnight Hyperglycemic Events
Time Frame: 12 hours after bedtime snack consumption (21:00-09:00)
|
Number of hyperglycemic events occurring during the overnight period following each bedtime snack intervention.
|
12 hours after bedtime snack consumption (21:00-09:00)
|
Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
Study record dates
These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.
Study Major Dates
Study Start (Actual)
November 19, 2020
Primary Completion (Actual)
November 19, 2020
Study Completion (Actual)
August 16, 2021
Study Registration Dates
First Submitted
August 13, 2026
First Submitted That Met QC Criteria
August 20, 2026
First Posted (Actual)
August 21, 2026
Study Record Updates
Last Update Posted (Actual)
August 21, 2026
Last Update Submitted That Met QC Criteria
August 20, 2026
Last Verified
August 1, 2026
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- BEDTIME-SNACK-T1D
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
YES
IPD Plan Description
De-identified individual participant data underlying the results reported in the publication may be shared upon reasonable request, subject to ethical and privacy restrictions and applicable institutional requirements.
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
No
Studies a U.S. FDA-regulated device product
No
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