Calories or Time Restriction to Alter Biomarkers of Aging and Diabetes

NCT05769335 | Completed

• 1 other identifier: H-2022-199
• Study Type: interventional
• Target: 114
• Locations: 1 country
• Sites: 1

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.

Conditions

Obesity

Keywords

Dietary intervention; Inflammation; Circadian rhythms; Cardiometabolic health

Outcome Measures

Primary Outcomes (1)

• Glucose area under curve (AUC) after 3 meals

  Change in glucose AUC after 3 meals

  8 weeks

Secondary Outcomes (4)

• Insulin area under the curve (AUC)

  8 weeks

• Fasting insulin

  8 weeks

• Fasting glucose

  8 weeks

• Change in glycated hemoglobin (HbA1c)

  8 weeks

Other Outcomes (20)

• Postprandial glucose and insulin AUC of each meal

  8 weeks

• Non-esterified fatty acids (fasting, postprandial AUC)

  8 weeks

• Triglycerides (fasting, postprandial AUC)

  8 weeks

Study Arms (3)

early calorie restriction (eCR)

EXPERIMENTAL

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

delayed calorie restriction (dCR)

EXPERIMENTAL

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

Calorie restriction (CR)

ACTIVE COMPARATOR

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

Interventions

eCR OTHER

Eating time window from 8:00 to 16:00

early calorie restriction (eCR)

dCR OTHER

Eating time window from 12:00 to 20:00

delayed calorie restriction (dCR)

CR OTHER

Eating time window from 8:00 to 20:00

Calorie restriction (CR)

Eligibility Criteria

• Age: 35 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• 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)

Sponsors & Collaborators

• University of Adelaide: lead
• University of Sydney: collaborator
• Salk Institute for Biological Studies: collaborator

Study Sites (1)

South Australian Health and Medical Research Institute / The University of Adelaide

Adelaide, South Australia, 5000, Australia

Location

MeSH Terms

Conditions

Obesity; Inflammation

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Pathologic Processes

Study Officials

• Leonie Heilbronn, PhD.

  The University of Adelaide

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Group Leader, Obesity and Metabolism

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

Study Record Dates

• First Submitted: March 1, 2023
• First Posted: March 15, 2023
• Study Start: March 15, 2023
• Primary Completion: December 10, 2024
• Study Completion: April 17, 2025
• Last Updated: May 9, 2025

Record last verified: 2025-05

Locations

AU (1)