Determining the Effect of Food Ordering on Blood Glucose In Gestational Diabetes Mellitus (DEFI-GDM) (DEFI-GDM)

Determining the Effect of Food Ordering on Blood Glucose In Gestational Diabetes Mellitus (DEFI-GDM) - a Randomised Crossover Study

The goal of this clinical trial is to determine whether the sequence of macronutrient consumption affects post-prandial glycaemia in women with gestational diabetes mellitus.

The main questions it aims to answer are:

• The difference in the magnitude of postprandial rise in blood glucose between the two test meals.
• The difference in the magnitude of postprandial change in serum levels of gut hormones between the two test meals.
• The difference in mean change in pre-post ingestion satiety scores between the two test meals.
• The difference in 24 hour energy and macronutrient intake following the two test meals.

Participants will attend two study visits at the Centre for Public Health, with an interval of at least two days between the visits and complete the following, anthropometric measurements, demographic and appetite questionnaires, glucose measurements, two food diaries and fasting blood samples and the consumption of the study breakfast. Participants will be asked to eat either the protein/fat-based component of the meal (scrambled egg) before or after the carbohydrate-based component (wholemeal toast) on their first visit and on the other visit they will be asked to eat the meal in the reverse order. The order in which this occurs will be randomised and each participant will act as their own control. Researchers will compare the results from participants between the two test meals to see if the order of macronutrient consumption has any effect on post-prandial glycaemia, gut hormones, satiety scores and energy and macronutrient intake.

Study Overview

• Status: Recruiting
• Conditions: Gestational Diabetes Mellitus (GDM)
• Intervention / Treatment: Other: Visit 1: Protein/fat then carbohydrate. Visit 2: Carbohydrate then protein/fat.; Other: Visit 1: Carbohydrate then protein/fat. Visit 2: Protein/fat then carbohydrate.

Detailed Description

Gestational diabetes mellitus (GDM) is glucose intolerance with onset or first diagnosis during pregnancy, affecting around 1 in 10 pregnancies in the United Kingdom (UK). Women with GDM are 10 times more likely to develop type 2 DM and twice as likely to develop cardiovascular disease in later life than women without GDM. Dietary modification is recommended as first line management to optimise blood glucose control. However, this often fails, necessitating the use of medication such as metformin and insulin. There is a pressing need to find safe and effective dietary approaches to optimise glycaemic control in GDM which can be easily adhered to in order to improve longer-term outcomes. The impact of the sequence of macronutrients on glycaemic control is an emerging area of interest. Recent evidence suggests that the consumption of the fat/protein components of a meal prior to the carbohydrate components, reduces the peak by around 40% after food. This study aims to determine whether the order that macronutrients (i.e. protein, fat, carbohydrate) are eaten affects; blood sugar glucose levels in the blood after a meal, appetite, food intake and the release of hormones in the body, in women with GDM.

Pregnant women with GDM, aged 18-50 years old are eligible for the study. Women are not eligible if they have a history of type 1 or 2 diabetes, any clinically confirmed food allergies, taking medication for GDM, severe nausea or using anti-sickness medication.

Recruitment will be via antenatal clinics in the South-Eastern Health and Social Care Trust (SEHSCT). Participants will attend the Centre for Public Health on two occasions (maximum 2 weeks between visits) and will involve the collection of demographic information, weight and height measurements, blood samples, glucose measurements, consumption of study breakfast, and completion of two 1-day food diaries.

Participants will be asked to eat either the protein/fat-based component of the meal (scrambled egg) before or after the carbohydrate-based component (wholemeal toast) on their first visit and on the other visit they will be asked to eat the meal in the reverse order. The order in which this occurs will be randomised and each participant will act as their own control. Scrambled egg was chosen as the protein and fat will be homogenously distributed (compared to boiled egg, for example). Wholemeal toast was chosen as, although lower glycaemic index and therefore less likely to expeditiously raise blood glucose than toasted white bread, it will be more consistent with the participants' existing dietary needs.

• Study Type: Interventional
• Enrollment (Estimated): 35
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Hannah O'Hara, MBBS BSc PhD DFSRH MRCGP; Phone Number: +44 (0) 28 9097 6350; Email: h.ohara@qub.ac.uk
• Study Contact Backup: Name: Danielle Logan, PhD; Phone Number: +44 (0) 28 9097 6350; Email: d.logan@qub.ac.uk

Study Locations

• United Kingdom
  • Belfast, United Kingdom, BT12 6BA
    • Recruiting
    • Centre for Public Health, Institute of Clinical Sciences A
    • Contact: Hannah O'Hara, MBBS BSc PhD DFSRH MRCGP; Phone Number: +44 (0) 28 9097 6350; Email: h.ohara@qub.ac.uk
    • Contact: Danielle Logan, PhD; Phone Number: +44 (0) 28 9097 6350; Email: d.logan@qub.ac.uk
    • Principal Investigator: Hannah O'Hara, MBBS BSc PhD DFSRH MRCGP
    • Sub-Investigator: Jayne Woodside, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Pregnant women with gestational diabetes mellitus
• Aged 18-50 years old

Exclusion Criteria:

• History of type 1 or type 2 diabetes mellitus
• Dietary restrictions or clinically confirmed food allergies that may affect study requirements
• Pharmacologically managed GDM at the point of study entry
• Hyperemesis gravidarum at the point of study entry (i.e. prolonged/severe nausea and vomiting)
• Using antiemetic medication (e.g. dimenhydrinate, prochlorperazine, promethazine)
• Any other problems or medical conditions that would substantially limit their ability to complete the study requirements

Participants can be recruited onto the study if they have previously had GDM in another pregnancy. Participants can also be recruited if they are involved in other research studies, but this will depend on the study type and the decision will be made by the Chief/Principal Investigator.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Visit 1: Protein/fat then carbohydrate. Visit 2: Carbohydrate then protein/fat.; Participants who are randomised to eat the protein/fat-based component (scrambled egg) of the meal before the carbohydrate-based component (wholemeal toast) on their first study visit and on their second study visit they will be asked to eat the meal in the reverse order. The order in which this occurs will be randomised and each participant will act as their own control.	Other: Visit 1: Protein/fat then carbohydrate. Visit 2: Carbohydrate then protein/fat.; Participants who are randomised to eat the protein/fat-based component (scrambled egg) of the meal before the carbohydrate-based component (wholemeal toast) on their first study visit, will be asked to eat the meal in the reverse order at their second study visit. Meals will be prepared by members of the research team who have completed Food Safety training. Participants will be asked to consume a 440kcal breakfast meal within 10 minutes, approximately 1.5 hours after arrival at their first study visit and approximately 30 minutes after arrival at their second study visit.
Experimental: Visit 1: Carbohydrate then protein/fat. Visit 2: Protein/fat then carbohydrate."; Participants who are randomised to eat the carbohydrate-based component (wholemeal toast) of the meal before the protein/fat-based component (scrambled egg) on their first study visit and on their second study visit they will be asked to eat the meal in the reverse order. The order in which this occurs will be randomised and each participant will act as their own control.	Other: Visit 1: Carbohydrate then protein/fat. Visit 2: Protein/fat then carbohydrate.; Participants who are randomised to eat the carbohydrate-based component (wholemeal toast) of the meal before the protein/fat-based component (scrambled egg) on their first study visit, will be asked to eat the meal in the reverse order at their second study visit. Meals will be prepared by members of the research team who have completed Food Safety training. Participants will be asked to consume a 440kcal breakfast meal within 10 minutes, approximately 1.5 hours after arrival at their first study visit and approximately 30 minutes after arrival at their second study visit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postprandial Glucose	The difference in the magnitude of postprandial rise in blood glucose between the two test meals.	Difference between Visit 1 [time 0 and 125 minutes] and Visit 2 [time 0 and 125 minutes]

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin	The difference in the magnitude of postprandial change in serum levels of insulin between the two test meals.	Difference between Visit 1 [time 0 and 30 minutes] and Visit 2 [time 0 and 30 minutes]
C-Peptide	The difference in the magnitude of postprandial change in serum levels of c-peptide between the two test meals.	Difference between Visit 1 [time 0 and 30 minutes] and Visit 2 [time 0 and 30 minutes]
Total Ghrelin	The difference in the magnitude of postprandial change in serum levels of total ghrelin between the two test meals.	Difference between Visit 1 [time 0 and 30 minutes] and Visit 2 [time 0 and 30 minutes]
Glucagon (GCG)	The difference in the magnitude of postprandial change in serum levels of GCG between the two test meals.	Difference between Visit 1 [time 0 and 30 minutes] and Visit 2 [time 0 and 30 minutes]
Glucagon-like peptide-1 (GLP-1)	The difference in the magnitude of postprandial change in serum levels of GLP-1 between the two test meals.	Difference between Visit 1 [time 0 and 30 minutes] and Visit 2 [time 0 and 30 minutes]
Peptide Tyrosine (PYY)	The difference in the magnitude of postprandial change in serum levels of PYY between the two test meals.	Difference between Visit 1 [time 0 and 30 minutes] and Visit 2 [time 0 and 30 minutes]
Satiety Scores	The difference in mean change in pre-post ingestion satiety scores between the two test meals, using an appetite visual analogue scale (range 0 - 100) [The direction of the score will depend on the individual question].	Difference between Visit 1 [time 0 and 30 minutes] and Visit 2 [time 0 and 30 minutes]
Nutrient intake	The difference in 24 hour energy and macronutrient intake following the two test meals.	Difference between Visit 1 [time 0 and 24 hours] and Visit 2 [time 0 and 24 hours]

Collaborators and Investigators

• Sponsor: Queen's University, Belfast
• Collaborators: Imperial College London
• Investigators: Principal Investigator: Hannah O'Hara, MBBS BSc PhD DFSRH MRCGP, Queen's University, Belfast

Study record dates

Study Major Dates

• Study Start (Actual): December 11, 2025
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): February 1, 2027

Study Registration Dates

• First Submitted: March 4, 2025
• First Submitted That Met QC Criteria: March 24, 2025
• First Posted (Actual): March 26, 2025

Study Record Updates

• Last Update Posted (Actual): April 17, 2026
• Last Update Submitted That Met QC Criteria: April 14, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Gestational Diabetes Mellitus; Post-prandial glycaemia; Food Ordering
• Additional Relevant MeSH Terms: Urogenital Diseases; Endocrine System Diseases; Female Urogenital Diseases and Pregnancy Complications; Metabolic Diseases; Pregnancy Complications; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes, Gestational
• Other Study ID Numbers: 25/NI/0004

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The researchers are happy to share results from the study for the purposes of a meta-analysis. This will be completed on approach to the researchers.
• IPD Sharing Time Frame: Data should be available from December 2025 and will be available for 2 years.
• IPD Sharing Access Criteria: Use of results in a meta-analysis will be available by contacting the research team.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No