Daily vs Intermittent Restriction of Energy: Controlled Trial to Reduce Diabetes Risk (DIRECT)
- Conditions
- Individuals at Risk of Developing Diabetes
- Interventions
- Other: Intermittent Fasting (IF)Other: standard care (SC)Other: Daily Restriction (DR)
- Registration Number
- NCT03689608
- Lead Sponsor
- University of Adelaide
- Brief Summary
In this randomized controlled trial, the investigators will compare the long term effectiveness of intermittent fasting (IF) versus an energy matched moderate calorie restriction (CR) over 18 months, and relative to a non-active intervention standard control (SC) in individuals who are at increased risk of developing type 2 diabetes. All participants will be required to attend the blood tests following a 12-hour overnight fast for the "A" visit at Month 0, 2, 6 (active) and 18 (follow up).
Fast424hGlucose: A subset of 100 participants enrolled in either IF or CR group in the parent study will be fitted with a continuous glucose monitor (CGM) to measure 24-hour glycaemic profile at month 0 and month 6.
Fast4Switch: Additional bloods will be collected after a "B" visit at month 6 to compare the fed to fasted switch. The B samples will be collected after a 12-hour overnight fast (CR, SC) or 20-hour fast (IF) to assess the metabolic switch to fasting in metabolites and hormones.
Fast4Stress: Additional subcutaneous adipose tissue, urine and saliva samples will be collected in \~32 men in IF and CR groups at month 0 and 6 at A and B visits to examine changes in stress response and resistance markers.
Experience2Fast: In-depth, semi-structured interviews will be carried out at month-8 follow-up visit in a subset of completers from IF or CR groups to explore the experience of intervention diets and understand contributing factors towards change and maintenance of dietary behaviours.
Fast4Flux: Additional blood samples will be collected in \~100 individuals in SC, IF and CR groups at month 0, month 2 and month 6 at A visit to measure autophagic flux in peripheral blood mononuclear cells following treatment of whole blood.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 209
- weight-stable (< 5 % fluctuation in their body weight for past 6-months at study entry)
- score 12 or greater on the AUSDRISK calculator
- HbA1c <48 mmol/mol (measured at screening)
- Personal history/diagnosis (self-reported) of diabetes (type 1 or 2), major psychiatric disorders (schizophrenia, major depressive disorder, bipolar disorder, eating disorders), gastrointestinal disorders, haematological disorders (i.e. thalassemia, iron-deficiency anaemia) insomnia, or any other medical condition, deemed unstable by the study physician.
- Participants currently taking the following medications will be excluded from participating: any medication used to lower blood glucose or antidiabetic medications (metformin, sulfonylureas, Glucagon-like peptide-1 GLP-1 analogues [i.e. exenatide], thiazolidinediones or DPP-IV inhibitors [i.e. 'gliptins']), medications affecting weight, appetite or gut motility (i.e. domperidone, cisapride, orlistat, phentermine, topiramate). Participants who are taking stable doses (i.e. > 12 months) of androgenic medications (i.e. testosterone) or SSRI's will not be excluded.
- weight change in past 3 months (> 5% screening weight)
- uncontrolled asthma, current fever, upper respiratory infections
- 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 recreational drugs
- regular blood donor
- unable to comprehend study protocol due to English language or cognitive difficulties
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Intermittent Fasting (IF) Intermittent Fasting (IF) 3 days fasting per week standard care (SC) standard care (SC) usual care Daily Restriction (DR) Daily Restriction (DR) daily energy restriction
- Primary Outcome Measures
Name Time Method Postprandial glucose AUC 6 months Change in postprandial glucose AUC
- Secondary Outcome Measures
Name Time Method Postprandial triglyceride 6 months, 18 months Change in postprandial triglyceride levels
Waist and hip circumference 2 months, 6 months, 18 months Change in waist and hip circumference
Dietary intake 2 months, 6 months, 18 months Change in food intake measured by self-reported food diaries
Body composition 6 months, 18 months Change in body fat mass (kg) and fat free mass (kg)
Postprandial glucose 18 months Change in postprandial glucose
Fasting glucose 2 months, 6 months, 18 months Change in fasting glucose
Fasting triglyceride 2 months, 6 months, 18 months Change in fasting triglyceride levels
HbA1c 2 months, 6 months, 18 months Change in HbA1c
Blood lipids 2 months, 6 months, 18 months Changes in blood lipid profile (total cholesterol, HDL-, LDL-cholesterol and triglycerides)
Blood pressure 2 months, 6 months, 18 months Change in systolic blood pressure and diastolic blood pressure (mmHg)
Postprandial insulin 6 months, 18 months Change in postprandial insulin
Postprandial non-esterified fatty acids (NEFA) 6 months, 18 months Change in postprandial NEFA levels
Body weight 2 months, 6 months, 18 months Change in body weight in kilograms
Changes in physical Activity assessed by accelerometer 2 months, 6 months, 18 months Change in average step counts measured with waist-worn actigraphy monitors
Fasting insulin 2 months, 6 months, 18 months Change in fasting insulin
Fasting non-esterified fatty acids (NEFA) 2 months, 6 months, 18 months Change in fasting NEFA levels
Trial Locations
- Locations (1)
University of Adelaide
🇦🇺Adelaide, South Australia, Australia