None listed
Conditions
Brief summary
The aim is to investigate the effect on insulin sensitivity of a high lean red meat diet with minimal dairy; a high dairy diet with no red meat; and a diet that has no red meat and minimal dairy with protein coming from chicken, fish and other sources. Evidence is conflicting about the benefits or risks of consuming meat and dairy products and there is little understanding of the mechanisms behind the findings observed in epidemiological studies. The primary hypothesis was that the red meat diet would produce greater insulin resistance than the high dairy diet with secondary hypotheses that the high dairy diet would produce greater insulin sensitivity than the diet without dairy and that these changes would be greater in those with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) than in those with normal glucose tolerance (NGT).
Interventions
This is a dietary intervention study to test the impact of three diets on insulin sensitivity:
1. A high lean red meat diet (200g-250g/day with minimal dairy for 6 days/week)
2. A high low-fat dairy diet (4-6 serves/day 6 days/week with reduced chicken/fish, <150g/day) and no red meat
3. A diet with no dairy or red meat with 200-250g meat coming from chicken, fish or other sources.
All dietary periods will be 4 weeks long, weight stable and have a 2 week wash-out period in between. All dietary p
This is a dietary intervention study to test the impact of three diets on insulin sensitivity: 1. A high lean red meat diet (200g-250g/day with minimal dairy for 6 days/week) 2. A high low-fat dairy diet (4-6 serves/day 6 days/week with reduced chicken/fish, <150g/day) and no red meat 3. A diet with no dairy or red meat with 200-250g meat coming from chicken, fish or other sources. All dietary periods will be 4 weeks long, weight stable and have a 2 week wash-out period in between. All dietary periods will be randomised. Overweight and obese volunteers (BMI 25-45) over the age of 20, will be divided into two groups: those with normal glucose tolerance and those with impaired glucose tolerance as demonstrated by a 75g oral glucose tolerance test administered after recruitment. All participants will follow the three diets. Height and weight will be measured at baseline, along with lean body mass which will be assessed by a DEXA scan. Weight will be measured at the beginning, middle and end of each 4-week diet period. A 75g oral glucose tolerance test will be performed at baseline and at the end of each diet period with blood samples taken at baseline, 30, 60 and 90 and 120 minutes for measurements of insulin and glucose. Instructions for each diet will be provided at the beginning of each intervention, and dietary compliance will be assessed by daily checklists and by weighed food records.
Sponsors
University of South Australia
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
20 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Men and women aged over 20 Divided into two groups - normal glucose tolerance and impaired glucose tolerance Eligible BMI >25
Exclusion criteria
Major metabolic illness such as kidney or liver disease; cardiovascular disease, type 2 diabetes; anyone on drugs influencing glucose metabolism (eg Metformin)
Outcome results
None listed