The Metabolic Impact of Intermittent Carbohydrate Restriction in Individuals With Type 2 Diabetes (INTERCARB)

The primary aim of this randomized cross-over intervention study is to investigate the effect of four weeks of intermittent carbohydrate restriction (alternating between two days of normal dietary intake and two days of carbohydrate restriction to 70-90 grams) on 24-hour average sensor glucose in individuals with type 2 diabetes compared with a four-week control period with normal dietary intake.

Study Overview

• Status: Recruiting
• Conditions: Diabetes Mellitus, Type 2; Metabolic Syndrome; Overweight and Obesity; Non-Alcoholic Fatty Liver Disease
• Intervention / Treatment: Other: Dietary macronutrient composition

• Study Type: Interventional
• Enrollment (Estimated): 14
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Amanda Schaufuss, MSc; Phone Number: +4530270261; Email: amanda.schaufuss@regionh.dk

Study Locations

• Denmark
  • Hvidovre, Denmark, 2650
    • Recruiting
    • Department of Endocrinology, Hvidovre Hospital
    • Contact: Kirstine Nyvold Bojsen-Møller, MD, PhD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Men or women
• 35-75 years old
• BMI >27 kg/m2
• Known type 2 diabetes in stable glucose lowering therapy (for three months) or with HbA1c >48 mmol/mol if no glucose lowering therapy

Exclusion Criteria:

• Anemia (hemoglobin <8 mmol/L for men and <7 mmol/L for women)
• TSH outside reference range
• Treatment with insulin, sulfonylurea, or SGLT2-inhibitors
• Treatment with systemic corticosteroids
• HbA1c >70 mmol/mol
• eGFR <90 ml/min/1.73 m2
• Contraindications for MR-scan: abdominal height exceed limitations of the MR-scanner, pacemaker or other electronic device implanted, implanted metal devices, severe claustrophobia
• Food allergies (including lactose and gluten intolerance)
• Vegetarian/vegan diet or following of specific dietary plans
• Alcohol consumptions >84/168 g/week (women/men)
• Strenuous activity level > 120 minutes per week
• Weight loss (>5 kg) within the last three months or previous bariatric surgery
• High risk of fibrosis of the liver (estimated by FIB4 score > 3.25)

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: Intermittent carbohydrate restriction; Four weeks of intermittent carbohydrate restriction: a dietary regime alternating between two days of restricting carbohydrate intake to 70-90 grams, while energy intake is ad libitum, from fat- and protein-containing foods, and two days of non-restricted diet.	Other: Dietary macronutrient composition; Intermittent carbohydrate restriction
No Intervention: Control arm; Four weeks of free-living with no dietary restrictions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
24-hour average sensor glucose	A patient-blinded continuous glucose monitoring (CGM) is worn during the last two weeks of both the intervention and control period.	24-hour average sensor glucose is measured as the average of eight consecutive days (starting from two days post sensor mounting) from the intermittent carbohydrate restriction period and the corresponding days of the control period (i.e. days 17-24).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Liver triacylglycerol content	Liver TG content will be measured by 1H-Magnetic Resonance Spectroscopy (MRS) on the day before and the day after the 4-week dietary intervention (i.e. day 0 and day 30) and on the day before and the day after the 4-week control period (i.e. day 0 and day 30).	day 30 adjusted for baseline
Fasting plasma concentrations of triacylglycerols	Fasting plasma concentrations of triacylglycerols measured on the day before and the day after the 4-week dietary intervention (i.e. day 0 and day 30) and on the day before and the day after the 4-week control period (i.e. day 0 and day 30).	day 30 adjusted for baseline

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Explorative outcomes - Questionnaires on quality of life	Participants will complete the questionnaires 'Problem Areas In Diabetes' & 'World Health Organisation-Five Well-Being Index'.	day 30
Explorative outcomes - Qualitative evaluation to assess feasibility of the dietary strategy	A semi-structured evaluation interview to assess social context, eating practices, compliance to, and feasibility and acceptability of the intermittent carbohydrate restriction regime will be carried out.	day 30

Collaborators and Investigators

• Sponsor: Hvidovre University Hospital
• Collaborators: University of Copenhagen; Danish Research Centre for Magnetic Resonance

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2024
• Primary Completion (Estimated): September 1, 2025
• Study Completion (Estimated): September 1, 2025

Study Registration Dates

• First Submitted: September 29, 2023
• First Submitted That Met QC Criteria: November 16, 2023
• First Posted (Actual): November 22, 2023

Study Record Updates

• Last Update Posted (Estimated): December 8, 2023
• Last Update Submitted That Met QC Criteria: December 7, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Overnutrition; Nutrition Disorders; Body Weight; Insulin Resistance; Hyperinsulinism; Liver Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2; Fatty Liver; Metabolic Syndrome; Overweight; Non-alcoholic Fatty Liver Disease
• Other Study ID Numbers: INTERCARB - H-23043085

Drug and device information, study documents

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