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

Sponsor

University of Adelaide (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05769335

Collaborator

University of Sydney (Other), Salk Institute for Biological Studies (Other)

114

Enrollment

Arms

33.1

Anticipated Duration (Months)

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Obesity	Other: eCR Other: dCR Other: CR	N/A

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 Design

Study Type:

Interventional

Anticipated Enrollment :

114 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Intervention Model Description:

The OMIT study will be a parallel, single-blinded, 3-arm randomised controlled trial.The OMIT study will be a parallel, single-blinded, 3-arm randomised controlled trial.

Masking:

None (Open Label)

Primary Purpose:

Basic Science

Official Title:

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

Anticipated Study Start Date :

Mar 1, 2023

Anticipated Primary Completion Date :

Oct 1, 2025

Anticipated Study Completion Date :

Dec 1, 2025

Arms and Interventions

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

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

Outcome Measures

Primary Outcome Measures

Glucose area under curve (AUC) after 3 meals [8 weeks]
Change in glucose AUC after 3 meals

Secondary Outcome Measures

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

Eligibility Criteria

Criteria

Ages Eligible for Study:

35 Years to 75 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

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

Contacts and Locations

Locations

No locations specified.

Sponsors and Collaborators

University of Adelaide
University of Sydney
Salk Institute for Biological Studies

Investigators

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

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

A/Prof Leonie Heilbronn, Group Leader, Obesity and Metabolism, University of Adelaide

ClinicalTrials.gov Identifier:

NCT05769335

Other Study ID Numbers:

H-2022-199

First Posted:

Mar 15, 2023

Last Update Posted:

Mar 15, 2023

Last Verified:

Mar 1, 2023

Studies a U.S. FDA-regulated Drug Product:

Studies a U.S. FDA-regulated Device Product:

Keywords provided by A/Prof Leonie Heilbronn, Group Leader, Obesity and Metabolism, University of Adelaide

Dietary intervention

Inflammation

Circadian rhythms

Cardiometabolic health

Study Results

No Results Posted as of Mar 15, 2023