Calories or Time Restriction to Alter Biomarkers of Aging and Diabetes (OMIT)

March 23, 2023 updated by: A/Prof Leonie Heilbronn, University of Adelaide

The Effects of Caloric Restriction Plus Time Restriction on Glycemia, Circadian Rhythms and Cardiometabolic Health

Type 2 diabetes and cardiovascular disease are an increasing problem in Australia and around the world, and are partly linked to increased rates of obesity, together with sedentary lifestyles. This study will compare caloric restriction (CR) diets that restrict the amount of food that is eaten with CR diets that also restrict the time that the food is eaten, to either early or late in the day, on risk factors for type 2 diabetes and cardiovascular diseases over 2 months.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

In a parallel groups design, a total of 114 individuals will be recruited. After a two-week lead in and collection of data from activity monitors and continuous glucose monitors, plus a 28 hour (h) metabolic ward in-patient stay, participants will be randomised into one of three groups (eCR, 8-hour early time restriction + calorie restriction (e.g. 8:00-16:00); dCR, 8-hour delayed time restriction + calorie restriction (e.g. 12:00-20:00); CR, caloric restriction (>12 hour eating window (e.g. 8:00-20:00). All participants will receive individualised menus and foods that will be delivered to their homes by a supermarket delivery service at energy balance for 1 week (baseline) and at 70% of energy balance for a further 8 weeks. Repeat assessment occurs from 6-8 weeks with the final metabolic ward stay at 8-weeks to assess changes in primary and secondary outcomes.

Study Type

Interventional

Enrollment (Anticipated)

114

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 Contact

Study Contact Backup

Study Locations

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

35 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Overweight or obesity (BMI 25.1 - 44.9 kg/m2)
  • Elevated waist circumference (race specific),
  • Elevated fasting blood glucose (>5.6 mmol/L).

Exclusion Criteria:

A personal history/diagnosis (self-reported) of:

  • diabetes (type 1 or 2)
  • major psychiatric disorders (schizophrenia, major depressive disorder, bipolar disorder, eating disorders)
  • gastrointestinal disorders/disease (including malabsorption)
  • haematological disorders (i.e. thalassemia, iron-deficiency anaemia)
  • insomnia
  • obstructive sleep apnea
  • night eating syndrome
  • diagnosis or treatment of cancer in the past 3 years (excluding non-melanoma skin cancer)
  • significant liver or kidney diseases that require ongoing medical care
  • previous or planned gastro-intestinal surgery (including bariatric surgery)
  • Congestive heart failure (NYHA stage 2 or above)
  • Previous myocardial infarction or significant cardiac event ≤ 6 months prior to screening
  • Previous cerebrovascular event ≤ 12 months prior to screening
  • Any autoimmune disease (i.e. rheumatoid arthritis)
  • Coeliac disease
  • Score less than 12 of the Australian Diabetes (AUSD) risk assessment tool
  • Do not eat for a 12 hour window each day for 5 or more days per week
  • Have extreme or restricted patterns of eating (i.e. following an intermittent fasting diet) or already engage in CR
  • Other dietary restrictions including vegans, gluten or nut allergies
  • Night shift-workers (>3 shifts per month)
  • pregnant, planning a pregnancy or currently breastfeeding
  • those who have lost or gained >5% of body weight in the last 6 months
  • donated blood in past 3 months
  • current smokers of cigarettes/marijuana/e-cigarettes/vaporisers
  • anyone unable to comprehend the study protocol or provide informed consent (i.e. due to English language or cognitive difficulties)
  • do not own, or are not comfortable using, a smart phone and applications

Currently taking the following medications:

  • Anti-diabetic medications that lower blood glucose including, but not limited to: SGLT2 inhibitors, metformin, sulfonylureas, glucagon-like peptide-1 (GLP-1) analogues [i.e. semaglutide], thiazolidinediones
  • affecting weight, appetite or gut motility, including, but not limited to semaglutide, domperidone, cisapride, orlistat, phentermine, topiramate.
  • Diuretics (i.e. frusemide, thiazides) or combination blood pressure medications containing a diuretic
  • Beta-blockers
  • Glucocorticoids
  • Anti-epileptic medications (i.e. pregabalin and gabapentin)
  • Tricyclic antidepressants
  • Some serotonin and norepinephrine reuptake inhibitors (i.e. vortioxetine, mirtazapine and venlafaxine)
  • Regular use of benzodiazepines or other sleep aids, including melatonin
  • Antipsychotic medications
  • Opioid medications unless combined with paracetamol in a single formulation and used occasionally on as needs basis

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: early calorie restriction (eCR)
Individuals will be provided with menus prescribed at 70% of calculated energy requirements and instructed to eat within 8 h/day (e.g. 8:00 - 16:00) every day for 8 weeks, except 1 evening meal per week off the program (i.e. Saturday nights) to assist with overall adherence.
Other: eCR
Eating time window from 8:00 to 16:00
Experimental: delayed calorie restriction (dCR)
Individuals will be provided with menus prescribed at 70% of calculated energy requirements and instructed to eat within 8 h/day (e.g 12:00 - 20:00) every day for 8 weeks, except 1 evening meal per week off the program (i.e. Saturday nights) to assist with overall adherence.
Other: dCR
Eating time window from 12:00 to 20:00
Active Comparator: Calorie restriction (CR)
Individuals will be provided with menus prescribed at 70% of calculated energy requirements every day for 8 weeks. The menus will encourage breakfast and after-dinner consumption of the snack to eat over at least a 12 hour time frame per day (e.g. 8:00 - 20:00), except 1 evening meal per week off the program (i.e. Saturday nights) to assist with overall adherence.
Other: CR
Eating time window from 8:00 to 20:00

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Glucose area under curve (AUC) after 3 meals
Time Frame: 8 weeks
Change in glucose AUC after 3 meals
8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Body weight
Time Frame: 8 weeks
Change in body weight
8 weeks
24 h glucose on ward (by continuous glucose monitor (CGM)
Time Frame: 8 weeks
Change in 24 h glucose on ward by CGM
8 weeks
Insulin AUCs
Time Frame: 8 weeks
Change in insulin AUC after 3 meals
8 weeks
Insulin sensitivity (calculated by Matsuda index where a higher score means greater insulin sensitivity)
Time Frame: 8 weeks
Change in insulin sensitivity
8 weeks
Fasting glucose
Time Frame: 8 weeks
Change in fasting glucose
8 weeks
Fasting insulin
Time Frame: 8 weeks
Change in fasting insulin
8 weeks
C-reactive protein (CRP)
Time Frame: 8 weeks
Change in hs-CRP
8 weeks
Physical activity by activity monitor
Time Frame: 8 weeks
Change in step count
8 weeks
Adherence to the prescribed eating window (+/- 1 hour) by smart phone application
Time Frame: 8 weeks
Adherence to the prescribed eating window(+/- 1 hour) by smart phone application
8 weeks
Change in fat mass
Time Frame: 8 weeks
Change in fat mass by bio-electrical impedance analysis
8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Adelaide

Collaborators

University of Sydney
Salk Institute for Biological Studies

Investigators

  • Principal Investigator: Leonie Heilbronn, PhD., The University of Adelaide

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)

March 15, 2023

Primary Completion (Anticipated)

October 1, 2025

Study Completion (Anticipated)

December 1, 2025

Study Registration Dates

First Submitted

March 1, 2023

First Submitted That Met QC Criteria

March 13, 2023

First Posted (Actual)

March 15, 2023

Study Record Updates

Last Update Posted (Actual)

March 27, 2023

Last Update Submitted That Met QC Criteria

March 23, 2023

Last Verified

March 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • H-2022-199

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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