The effect of a protein/fibre drink on postprandial glycaemic metabolism in type 2 Diabetes Mellitus.

1. Written informed consent;

2. Age > 45 years;

3. Women: postmenopausal;

4. 25 < BMI > 35 kg/m2;

5. Type 2 diabetes mellitus with an HbA1C > 6.0 and < 8, preferably >6.4 and < 8, stable for the past 3 months as judged by the investigator;

6. No antidiabetic medication (i.e. sulphonylureas, insulin treatment) with the exemption of a stable and controlled anti-diabetic regime with metformin for at least 2 months and maximally 2000 mg/day and expected to remain stable throughout the duration of the study;

7. Willing to comply with the study protocol.

1. On a weight loss diet;

2. Any gastrointestinal disease that interferes with bowel function and nutritional intake (i.e. diabetes related constipation or diarrhoea secondary to neuropathy, diarrhoea due to chronic inflammatory bowel disease, gastroparesis, (partial) gastrectomy or any other procedure for stomach volume reduction, including gastric banding);

3. Significant heart (NYHA class IV), pulmonary, hepatic (transaminase greater than 3 times normal), renal disease (requiring dialysis or creatinine >150 µmol/l) or metabolic disorders;

4. Uncontrolled thyroid and/or adrenal disease, interfering malignant or haematological diseases;

5. Blood pressure > 160/90 mmHg , severe dyslipidemia (cholesterol > 8 mmol/l, triglycerides > 4 mmol/l);

6. Major infections (requiring antibiotics) within 3 weeks prior to study entry;

7. Concomitant therapy with sulfonylurea derivatives, acarbose, meglitinides, DPP-IV inhibitors, thiazolidinediones or insulin;

8. The use of drugs: all drugs that affect insulin secretion or insulin sensitivity, drugs or supplements that affect stomach pH, intestinal absorption and intestinal motility, moreover all concomitant medication should be discussed, in particular antiviral, oestrogens, progestagens, androgens, thiazide diuretics and anti-psychotic drugs;

9. Concomitant therapy with systemic glucocorticoids within 2 weeks prior to study entry;

10. Requirement of a fibre-free diet;

11. Alcohol intake of more than 21 alcohol containing drinks per week for men and 14 for women and the use of other drugs (e.g. marihuana and other soft drugs);

12. Investigator's uncertainty about the willingness or ability of the patient to comply with the protocol;

13. Participation in other clinical trials within 4 weeks of study entry.