Precision Nutrition Versus Standard Dietary Care: Continuous Glucose Monitoring as a Tool for Guided Nutrition Care in Type 2 Diabetes - The PRECISE-DIET Trial. -A Pilot Study

The primary aim of this pilot study is to assess the feasibility of a 12-week dietary intervention combined with the use of CGM in adults with T2D. The results of the pilot study will provide insights into recruitment, design, and the effectiveness of the intervention for the future long-term (12-month) PRECISE-DIET STUDY

Study Overview

• Status: Recruiting
• Conditions: Type 2 Diabetes
• Intervention / Treatment: Other: The precise diet intervention

Detailed Description

In recent decades, there has been a significant rise in the development and use of glucose lowering drugs aimed at improving glycemic control in individuals with type 2 diabetes (T2D). Despite medical advancements, more than one-third of the danish population with T2D have a hemoglobin A1c (HbA1c) exceeding the recommended thresholds. One limiting factor in supporting individuals achieve their glycaemic target may be driven by substantial postprandial increases in plasma glucose levels, which is influenced by the quantity and type of carbohydrates in meals, underscoring the critical role of dietary interventions as an integral component of T2D management.

Recent studies have demonstrated that the use of continuous glucose monitors (CGMs), which allow individuals to track their glucose profiles continuously throughout the day, improves glycemic control in T2D patients. However, these studies often exclude dietary interventions, which could potentially yield greater improvements in blood glucose regulation.

Nutritional research in recent years has focused on dietary patterns such as low-fat diets, the paleo diet, and vegan diets. Nevertheless, these studies have not sufficiently addressed individualized dietary adjustments to mitigate postprandial glucose excursions, despite their substantial importance for glycemic control.

Several clinical studies have revealed significant inter-individual variations in glycemic responses to identical standardized meals, highlighting the necessity of a personalized approach to dietary recommendations, particularly with a focus on carbohydrate intake.

The primary aim of this pilot study is to assess the feasibility of a 12-week dietary intervention combined with the use of CGM in adults with T2D. The results of the pilot study will provide insights into recruitment, design, and the effectiveness of the intervention for the future long-term (12-month) PRECISE-DIET STUDY

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Bettina Ewers, PhD; Phone Number: 0045 30912997; Email: bettina.ewers@regionh.dk

Study Locations

• Denmark
  • Herlev, Denmark, 2730
    • Recruiting
    • Steno Diabetes Center Copenhagen
    • Contact: Bettina Ewers, PhD; Phone Number: 0045 30912997; Email: bettina.ewers@regionh.dk

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• T2D

  • Diabetes duration of ≥12 months
  • ≥18 years of age
  • HbA1c ≥58 mmol/mol
  • Attending the SDCC outpatient clinic
  • Provided voluntary signed informed consent.

Exclusion Criteria:

• Inability to understand the patient information.
• Complications which do not permit to lowering HbA1c to <58 mmol/mol.
• Treatment with insulin.
• Low daily carbohydrate intake (defined as below 25 E% or 100 g/day) prior to study inclusion.
• Systematic use of corticosteroids.
• Using or requiring a specialized diet (e.g., kidney diet).
• Circumstances that affect HbA1c (e.g., liver disease and anaemia).
• Known or suspected drug or alcohol abuse (judged by the investigator).
• Pregnancy or breastfeeding or plans of pregnancy within the study period.
• Participation in other clinical trials.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Precise diet intervention; The precise diet intervention for 12 weeks (n=20).

Other: The precise diet intervention; The intervention includes training and education in CGM use and reduction in overall carbohydrate intake guided by individualized flexible nutrition recommendations, with adjustments made according to postprandial blood glucose responses. Staff will guide participants in the daily carbohydrate intake with personalized adjustments to accommodate individual needs by the individuals. The primary goal is to minimize the participant's time spent above 10 mmol/l

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fidelity testing	Participants will be invited to a workshop to evaluate the intervention and its components. Procedures from fidelity testing will be applied in the evaluation. These specific topics will be evaluated: Study designo Is the design appropriate? E.g., number of visits, CGM use, dietetic feedback?; Sampling strategyo E.g., how many participated, recruitment methods, sample diversity?; Treatment receipt"What is learned?"Is the intervention relevant to and accepted by the participants?; Treatment enactmentWhat is actually used and done?Do participants' "behavioural skills" improve?	12 weeks after baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
HbA1c (mmol/mol)	Assessed from blood samples	Measured at baseline and after 12 weeks
Time in range (TIR)	Time spent in time in range 3.9 mmol/l - 10.0 mmol/l from CGM data	Measured at baseline and after 12 weeks
Time above range (TAR)	Time spent in time above range 10.1-13.9 mmol/l from CGM data	Measured at baseline and after 12 weeks
Time below range (TBR)	Time spent in time below range <3.9 mmol/l from from CGM data	Measured at baseline and after 12 weeks
Coefficient of variation (CV)	Percentage coefficient of variation in glucose differences	Measured at baseline and after 12 weeks
Estimated HbA1c	Estimated HbA1c (14-days average of the CGM data)	Measured at baseline and after 12 weeks
Body mass index (kg/m^2)	Calculated from body weight (kg) and height (m).	Measured at baseline and after 12 weeks
Body weight (kg)	Measured on a digital scale	Measured at baseline and after 12 weeks
Waist circumference (cm)	Measured using tape measure.	Measured at baseline and after 12 weeks
Hip circumference (cm)	Measured using tape measure	Measured at baseline and after 12 weeks
Systolic blood pressure (mmHg)	Measured under resting	Measured at baseline and after 12 weeks
Diastolic blood pressure (mmHg)	Measured under resting	Measured at baseline and after 12 weeks
Self-reported diabetes distress	Assessed from the Problem Areas in Diabetes Scale comprising of twenty emotional-distress questions. Each item can be rated from 0 to 5.	Measured at baseline and after 12 weeks
Self-reported treatment satisfaction	Assessed from the questionnaire Diabetes Treatment Satisfaction Questionnaire (DTSQ).	Measured at baseline and after 12 weeks
Dietary intake	Dietary intake (total energy intake and macronutrient composition based on 3-days' diet records)	Measured at baseline and after 12 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in glucose lowering drugs	Medication status, change in doses or discontinuation of medicine	Measured at baseline and after 12 weeks
Personality trait assesment	Assesed fromt the BIG FIVE Inventory questionnaire (BFI-44). Comprising of 44 items.	Baseline
Physical activity	Physical activity levels measured by X3 accelerometers	Measured at baseline and after 12 weeks

Collaborators and Investigators

• Sponsor: Steno Diabetes Center Copenhagen
• Investigators: Principal Investigator: Bettina Ewers, PhD, Steno Diabetes Center Copenhagen

Study record dates

Study Major Dates

• Study Start (Actual): November 18, 2025
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): August 31, 2026

Study Registration Dates

• First Submitted: January 9, 2025
• First Submitted That Met QC Criteria: February 14, 2025
• First Posted (Actual): February 18, 2025

Study Record Updates

• Last Update Posted (Actual): February 10, 2026
• Last Update Submitted That Met QC Criteria: February 9, 2026
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Type 2 diabetes; CGM; continuous glucose monitoring; Dietary intervention
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes Mellitus, Type 2
• Other Study ID Numbers: H-24083559

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No