Diabetes, Obesity
Conditions
Keywords
Human nutrition, Dietary fibre, Insulin resistance, Obesity, Glucose, Colonic fermentation, Short chain fatty acids, GLP-1, Appetite, Abdominal fat
Brief summary
High intake of cereal fibre has been shown to be associated with reduced weight gain and improved insulin sensitivity. We hypothesize these effects are due to the short chain fatty acids derived from the bacterial fermentation (breakdown) of fibre in the colon (large intestine). Insulin resistant subjects will be randomized to receive 2 servings of a low-fibre cereal (eg. puffed rice) or 2 servings of a high-fibre cereal (wheat bran cereal) per day for one year. The effects of the diets on body weight, appetite, abdominal fat, blood short chain fatty acids, glucose, insulin, lipids and hormones will be measured
Interventions
DRUGLow fibre breakfast cereal (puffed rice/cornflakes)
DRUGHigh fibre cereal (All Bran/Bran Flakes)
Sponsors
Canadian Diabetes Association
Canadian Institutes of Health Research (CIHR)
University of Toronto
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Non-diabetic male or non-pregnant females * aged 18-60 * BMI\<36 * fasting insulin \>40pmol/L (70%ile)
Exclusion criteria
* intention to lose \>5kg in weight * presence of diabetes (fasting glucose \>6.9mmol/L) * use of diuretics, beta-blockers or weight reducing drugs * use of antibiotics in last 3 months and use of antibiotics more than once annually for the last 2 years * significant gastrointestinal, liver or kidney disease * use of lipid-lowering drug * major medical or surgical event in last 6 mo. * fibre intake \>30g/d * inability to eat low or high fibre breakfast cereals * unwilling or unable to give consent or comply with protocol
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Serum acetate concentration | 0, 3, 6, 9 and 12 months |
| Serum butyrate concentration | 0, 3, 6, 9 and 12 months |
| Plasma GLP-1 concentration | 0, 3, 6, 9 and 12 months |
Secondary
| Measure | Time frame |
|---|---|
| Body weight | 0, 3, 6, 9 and 12 months |
| waist circumference | 0, 3, 6, 9 and 12 months |
| Abdominal fat | 0 and 12 months |
| food intake | 0, 3, 6, 9 and 12 months |
| Fasting glucose and insulin | 0, 3, 6, 9 and 12 months |
| Fasting and postprandial free fatty acids and triglycerides | 0, 3, 6, 9 and 12 months |
| Fasting and postprandial c-peptide | 0, 3, 6, 9 and 12 months |
| C-peptide/insulin ratio as marker of hepatic insulin extraction | 0, 3, 6, 9 and 12 months |
| Fasting lipids (cholesterol, triglyceride, HDL, LDL) | 0, 3, 6, 9 and 12 months |
| HOMA insulin resistance and beta cell function | 0, 3, 6, 9 and 12 months |
| postprandial glucose and insulin | 0, 3, 6, 9 and 12 months |
Countries
Canada
Outcome results
None listed