Calories or Time Restriction to Alter Biomarkers of Aging and Diabetes

Obesity Clinical Trial

— OMIT  

Official title:

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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05769335
• Other study ID #: H-2022-199
• Status: Recruiting
• Phase: N/A
• Start date: March 15, 2023
• Est. completion date: December 2025

Study information

• Verified date: March 2023
• Source: University of Adelaide
• Contact: Leonie Heilbronn, PhD.
• Phone: +61424187880
• Email: leonie.heilbronn[@]adelaide.edu.au
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 114
• Est. completion date: December 2025
• Est. primary completion date: October 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 35 Years to 75 Years

Eligibility

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

Related Conditions & MeSH terms

• Obesity

Intervention

Other:
• eCR
Eating time window from 8:00 to 16:00
• dCR
Eating time window from 12:00 to 20:00
• CR
Eating time window from 8:00 to 20:00

Locations

Country	Name	City	State
Australia	South Australian Health and Medical Research Institute / The University of Adelaide	Adelaide	South Australia

Sponsors (3)

Lead Sponsor	Collaborator
University of Adelaide	Salk Institute for Biological Studies, University of Sydney

Country where clinical trial is conducted

Australia, 

Outcome

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