None listed
Conditions
Brief summary
The primary goal of the Preview intervention study is to identify the most efficient lifestyle pattern for the prevention of type-2 diabetes in a population of pre-diabetic overweight or obese individuals (i.e those at high risk of diabetes). This will be done by conducting a clinical randomized intervention trial of 3 years duration in a total 310 pre-diabetic adults in Australia.
Interventions
The study consists of two distinct parts, i.e an 8 week weight reduction period followed by a 148 week randomized weight maintenance, diet and exercise intervention.
All participants are put on an energy restricted low calorie diet (LCD) consisting of 800-1000kcal/d with a target macronutrient composition of 15-20% of total energy from fat, 35-40% from protein and 45-50% from carbohydrate. The participants will be provided with nutritionally complete meal replacement LCD products (4 sachets pe
The study consists of two distinct parts, i.e an 8 week weight reduction period followed by a 148 week randomized weight maintenance, diet and exercise intervention. All participants are put on an energy restricted low calorie diet (LCD) consisting of 800-1000kcal/d with a target macronutrient composition of 15-20% of total energy from fat, 35-40% from protein and 45-50% from carbohydrate. The participants will be provided with nutritionally complete meal replacement LCD products (4 sachets per day) supplied by Cambridge Weight Plan U.K. for 8 weeks, aiming for a minimum 8% reduction in weight. The post-LCD phase aims to prevent Type 2 Diabetes by modifying lifestyle factors such as diet and physical activity to promote healthy weight maintenance. The participants are randomized into two different diet interventions and two exercise interventions for a total of 148 weeks. The 2 diet interventions are: 1. Moderate Protein (MP) Diet: protein 15% of total energy intake (E%), carbohydrates 55 E%, and a dietary glycaemic index (GI) greater than 56; 2. High protein (HP) Diet: protein 25 E%, carbohydrates 45 E%, GI less than 55. Both diet interventions focus on healthy food items to be consumed ad libitum with respect to energy. A dietitian will educate participants on portion sizes, healthy eating habits to achieve the macronutrient and GI prescription and self-monitoring in order to maintain weight loss. The two exercise interventions are: 1. Moderate Intensity (MI): 60-75% of maximal heart rate (HRmax) 150mins total/week (frequency 3-5 times) e.g. brisk walking. 2. High intensity (HI): 76-90% HRmax for 75 mins total/week (frequency 2-3 times) e.g. running. In the first weeks of the weight maintenance phase the participants will work with an exercise physiologist to plan their physical activity program including a 4week period where exercise levels are slowly introduced to reach the intended prescribed program.
Sponsors
The University of Sydney
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
25 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
1. Body Mass Index greater than 25kg/m2 2. WHO/IDF (International Diabetes Foundation) definition of pre-diabetes: Impaired fasting glucose (IFG) 5.6-6.9mmol/l or Impaired glucose tolerance (IGT) Venous plasma glucose concentration of 7.8-11.0 mmol/l at 2 hrs after oral administration of 75g glucose (oral glucose tolerance test (OGTT)), with fasting plasma glucose less than 7.0 mmol/l.
Exclusion criteria
1. Diabetes (other than gestational diabetes). 2. Systolic blood pressure above 160 mmHg and/or diastolic blood pressure above 100mmHg 3. Previous bariatric surgery 4. Significant health problems
Outcome results
None listed