Understanding Acute Dietary Changes After GLP-1 Agonist Treatment: The GLaD Feasibility Study (GLaD)

Understanding the Dietary Adjustments Following GLP-1 Agonist Treatment: The GLaD Feasibility Study

An observational study of those who have been prescribed a GLP-1 agonist therapy (yet to commence), for either weight or diabetes management, and are willing to complete dietary records and questionnaires of behaviour and psychosocial health.

Study Overview

• Status: Completed
• Conditions: Obesity; Type 2 Diabetes Mellitus (T2DM)

Detailed Description

Forty individuals (20 for weight management, 20 for diabetes management) living in Australia who have been prescribed a GLP-1 agonist (no previous prescription or no use in the previous 6 months) will be recruited to participate over the initial 3 months of their treatment. Assessments will occur remotely (online) at baseline, 2 weeks, 1 month and 3 months. Optional body composition assessments will be provided at baseline and 3 months for those based in Melbourne, Australia.

• Study Type: Observational
• Enrollment (Actual): 37

Contacts and Locations

Study Locations

• Australia
  • Victoria
    • Fitzroy, Victoria, Australia, 3065
      • Australian Catholic University

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Individuals living in Australia who are intending to commence a GLP-1 prescription

Description

Inclusion Criteria:

• Aged 18+ years old
• Intending to commence a prescription for a GLP-1 agonist (may be dual agonist, i.e. Ozempic, Trulicity, Monjaro, or Saxenda) medication, with no use in the previous 6 months
• The primary reason for commencing the medication will be for diabetes or weight management
• Willing to participate in dietary recall and questionnaires

Exclusion Criteria:

• Aged under 18 years,
• used a GLP-1 agonist medication in the previous 6 months,
• unwilling or unable to provide dietary recalls
• non-English speaking.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Weight management; Prescribed GLP-1 agonist therapy primarily for weight management
Type 2 diabetes; Prescribed GLP-1 agonist therapy primarily for glycemic management

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of recruitment	The rate of recruitment and the retention rate of participants completing the dietary assessment measures.	4 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Energy intake	Assessed using Intake24 records for at least 2 days per timepoint	baseline, 2 weeks, 1 month, 3 months
Medication symptomology	Incidence of self-reported side effects	baseline, 1 month, 3 months
Medication use	Dosage	baseline, 1 month, 3 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient perspectives	Qualitative interview after end of the observation period	3 months
Macronutrient intake	Proportion of carbohdyrate, fat, protein, alcohol and fibre intake assessed through dietary records	baseline, 2 weeks, 1 month, 3 months
Diet quality	Assessed using Healthy Eating Index for Australian adults (HEIFA) from diet records (Intake24)	baseline, 2 weeks, 1 month, 3 months
Meal timing	Daily eating window and meal timing	baseline, 2 weeks, 1 month, 3 months
Medication use	Timing of medication use	baseline, 1 month, 3 months
Retrospective subjective appetite	Assessed using adaptive visual analogue scales with appetite questions as per Flint et al 2020 and used by Ravussin et al 2025, scored between 0 to 100, with a higher score meaning higher appetite ratings	baseline, 1 month, 3 months
Treatment self-regulation	Assessed using Treatment Self-regulation Questionnaire, 15 questions which are scored between 1 (not at all) and 7 (completely true) in response to questions	baseline, 1 month, 3 months
Food cravings	Assessed using Control of Eating Questionnaire (COEQ), a 21 questionnaire survey with a 0-100 scale where higher responses indicate higher severity of food cravings.	baseline, 1 month, 3 months
Internalisation of weight bias	Assessed using Weight Bias Internalisation Scale-Modified (WBIS-M), which includes 11 questions that are answered on a 1 (strongly disagree) to 7 (strongly agree) scale, noting that 2 questions are reverse scored.	baseline, 1 month, 3 months
Intuitive eating	Assessed using Intuitive Eating Scale 3 (IES-3), including 12 questions with options from 1 (strongly disagree) to 5 (strongly agree) where the higher total score indicates higher intuitive eating (Tykla et al, Appetite, 2024)	baseline, 1 month, 3 months
Health-related quality of life	Assessed using Short Form-36 (SF-36) questionnaire, where 36 questions are asked regarding the previous 4 weeks. Questions are given a score between 0 to 100 depending, and the overall score is the average of all questions.	baseline, 1 month, 3 months
Well being	Quality of life assessed using WHO-5 well being index, including 5 questions scored from 0 (none of the time) to 5 (all of the time), where a higher total score indicates better quality of life.	baseline, 1 month, 3 months
Binge eating	Assessed using Binge eating scale, which includes 16 questions. The total score ranges from 0 to 46, with higher scores correlating with more frequent and severe binge eating behaviours.	baseline, 1 month, 3 months
Disordered eating behaviours	Assessed using Eating Disorders Examination Questionnaire (EDEQ) 6.0, using 28 questions which are scored on 4 sub-scales and a global score is generated as an average of the 4 sub-scales. A higher score indicates greater disordered eating behaviours.	baseline, 1 month, 3 months
Physical activity	Assessed using International Physical Activity Questionnaire (long), which is 27 questions which asks duration (minutes) and frequency (days) of physical activity measured in domains of: 1) Job-related; 2) Transportation; 3) Housework, house maintenance, caring for family; 4) Recreation, sport, and leisure-time; and 5) Time spent sitting. An overall score is calculated using responses to all questions, where a higher score equates to greater physical activity.	baseline, 1 month, 3 months
Dietary changes	Assessed using Australian Eating Survey Food Frequency Questionnaire (FFQ), which has 120-item with 15 supplementary questions. The FFQ is designed to collect information about dietary intake over the participants previous 3 months.	baseline, 3 months
Micronutrient intake	Proportion of micronutrient intake (i.e. including but not limited to sodium, calcium, iron, zinc, vitamins, etc) assessed through dietary records	baseline, 2 weeks, 1 month, 3 months

Collaborators and Investigators

• Sponsor: Australian Catholic University
• Collaborators: St Vincent's Hospital Melbourne; The University of Queensland
• Investigators: Principal Investigator: Evelyn B Parr, PhD, Australian Catholic University

Study record dates

Study Major Dates

• Study Start (Actual): May 28, 2025
• Primary Completion (Actual): January 7, 2026
• Study Completion (Actual): January 7, 2026

Study Registration Dates

• First Submitted: May 22, 2025
• First Submitted That Met QC Criteria: June 1, 2025
• First Posted (Actual): June 3, 2025

Study Record Updates

• Last Update Posted (Actual): March 2, 2026
• Last Update Submitted That Met QC Criteria: February 26, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: psychosocial health; dietary behaviours
• Additional Relevant MeSH Terms: Endocrine System Diseases; Nutrition Disorders; Metabolic Diseases; Overnutrition; Body Weight; Glucose Metabolism Disorders; Diabetes Mellitus; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Diabetes Mellitus, Type 2
• Other Study ID Numbers: 2025-4090H

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data that support the findings of this study will be available from the corresponding author for a period of 36 months from publication, upon reasonable request for academic use. The data will not be made publically available, as it contains information that could compromise research participant consent.
• IPD Sharing Time Frame: 36 months from date of publication
• IPD Sharing Access Criteria: Reasonable requests of data for academic use will be considered. Requests can be made to the corresponding author of the publication. Data will not be made publicly available as it contains information that could compromise research participant consent.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

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