Type2 Diabetes, Obesity
Conditions
Brief summary
This study will explore the effects of eight weeks of time-restricted feeding (TRF) on body weight and composition, glycaemic control, 24-hour glucose profiles, glucoregulatory hormones, and cardiovascular risk in men at high risk of type 2 diabetes. The investigators hypothesise that 8 weeks of TRF will reduce body weight, improve body composition, improve glycaemic control and blood lipid profiles. The potential mechanism will be explored in terms of the changes in gene expression patterns and multi-omics level (e.g., adipose tissue transcriptome, blood proteome).
Detailed description
Following a 2 week baseline monitoring phase (food intake by smartphone APP, activity by accelerometer, glucose by continuous glucose monitor), participants will attend the metabolic clinic for testing (visit 0). Body weight, body composition (by DEXA), and blood pressure will be assessed. Blood and adipose tissue samples will be collected over 24-hour period for assessment of glucose, insulin, glucoregulatory hormones, blood lipids and adipose tissue transcriptome. Glucose and insulin responses to a standardised breakfast will be measured. All food will be provided for 3 days prior to the metabolic visit. Following visit 0, participants will be instructed to eat only within a 10-hour time frame each day for 8 weeks. Participants may self-select the precise window that best suits their lifestyles, however any food and drink must be consumed at least 3 hours prior to their usual bedtime. 24-hour glucose profiles, activity and food intake will be measured again at week 6-8. At the end of the 8 weeks, participants will return for a follow-up metabolic visit, identical to that at visit 0, except foods are provided with the 10h time frame.
Interventions
BEHAVIORALTRF
Participants will be instructed to consume their habitual diet within a self-selected 10 hour period every day.
Sponsors
University of South Australia
Salk Institute for Biological Studies
University of Adelaide
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
40 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Waist circumference ≥94 cm * Weight-stable (\< 5 % fluctuation in their body weight for past 6-months at study entry)
Exclusion criteria
* Personal history and/or diagnosis of: diabetes, cancer, major psychiatric disorders, liver disease, gastro-intestinal surgery or disease (including malabsorption), eating disorders, anaemia, insomnia, cardiovascular disease deemed unstable by the study physician. * use of prescribed or non-prescribed medications which may affect energy metabolism, gastrointestinal function, body weight or appetite, sleep (e.g: domperidone and cisapride, anticholinergic drugs (e.g.: atropine), metoclopramide, orlistat, thyroid medications, diuretics, glucocorticoids, sex steroids, metformin, dipeptidyl peptidase-IV inhibitors, melatonin) * recent weight change in past 3 months (\> 5% current body weight) * individuals who regularly perform high intensity exercise (\>2 week) * current intake of \> 140g alcohol/week * current smokers of cigarettes/cigars/marijuana/e-cigarettes/vaporisers * current intake of any illicit substance * unable to comprehend study protocol * currently performing shift work * has undertaken, or is planning to undertake, trans meridian travel during the study period, or the preceding 60 days * do not own a smartphone * eats for less than a 12-hour period per day
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Glycaemia | 2.5 hours | Change in postprandial glucose (iAUC) following a standard breakfast |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Blood lipids | 8 weeks | changes in blood lipid profile (total cholesterol, HDL-, LDL- cholesterol and triglycerides) |
| Physical activity and sleep | 8 weeks | An ancillary study will measure the changes in sleep and physical activity monitored by a wrist actigraph for 14 days. |
| Food intake and meal timing | 8 weeks | An ancillary study will measure the changes in food intake and meal timing as recorded via a photography based smartphone App over 2 weeks. The analysis of the App data including but not limited to eating duration at baseline, changes in eating duration after intervention, calorie distribution throughout the day, meal frequency, meal intervals, and macronutrients intake. |
| Continuous glucose monitoring | 8 weeks | An ancillary study will measure the changes in glucose level by CGM for 14 days. Daily glucose patterns including free habitual diet, 3-day lead-in food will be measured separately. The analysis of the CGM data including but not limited to assess the mean amplitude of glycaemic excursions (MAGE), continuous overall net glycaemic action (CONGA), mean glucose concentrations. |
| Objective sleep | 8 weeks | Changes in objective sleep status measured by laboratory polysomnography (PSG). |
| Insulin | 2.5 hours | Change in fasting and postprandial insulin following a standard breakfast. |
| HbA1c | 8 weeks | Change in HbA1c |
| Body weight | 8 weeks | Change in body weight |
| Body composition | 8 weeks | Change in body fat mass and fat free mass |
| Waist and hip circumference | 8 weeks | Change in waist and hip circumference |
| 24-hour glucose profile | 8 weeks | Change in 24-hour glucose profiles assessed by continuous glucose monitoring |
| Blood pressure | 8 weeks | Changes in systolic blood pressure and diastolic blood pressure |
| Non-esterified fatty acid (NEFA) | 8 weeks | Change in non-essential fatty acid (NEFA) |
| Plasma gastrointestinal (GI) hormones | 8 weeks | Changes in concentration of fasting and postprandial GI hormones in plasma (ghrelin, glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide, peptide YY) following a standard breakfast. |
| Plasma cortisol | 8 weeks | Changes in concentration of cortisol in hourly plasma samples assessed from 6am to 12pm. |
| Plasma Melatonin | 8 weeks | Changes in dim light melatonin onset (DLMO) assessed from 5pm to 3am |
| Adipose tissue transcriptome | 8 weeks | A subset will be measured for the change in the adipose tissue transcriptome in 6-hourly samples by RNA-sequencing. The data analysis including but not limited to the changes in numbers of genes oscillated in a diurnal manner, and pathway analysis. |
| Evening glycaemia | 8 weeks | An ancillary study will be performed to measure the changes in the concentration of plasma glucose, insulin and GI hormones (ghrelin, glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide, peptide YY) following a standard evening meal. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Metagenomics and metabolomics | 8 weeks | Changes in metagenome and metabolome in a subset of participants will be assessed in faeces by shotgun metagenomics sequencing and metabolites analysis. The data analysis including but not limited to the function and composition of the gut microbiota, and faecal bile acids. |
| Plasma proteome | 8 weeks | Plasma proteome will be assessed by mass-spectrometry driven analysis. The data analysis including but not limited to the changes in numbers of proteins oscillated in a diurnal manner, and pathway analysis. |
| Resting metabolic rate | 8 weeks | A subset of participants will be examined for the changes in resting metabolic rate and respiratory quotient. |
| Hair follicle clock gene expression | 8 weeks | Changes in the circadian pattern of clock gene expression in hair follicles. |
Countries
Australia
Outcome results
None listed