overweight/obese (bmi ≥ 28 kg/m2 < 40 kg/m2) insulin impaired men and post-menopausal women with impaired glucose tolerance (igt: 2h plasma glucose during 75g ogtt 7.8-11.1 mmol/l) and/or impaired fasting glucose (plasma glucose ≥ 5.6 mmol/l) aged 45-70 years will be included in the study.

in addition, subjects have to be weight-stable for at least 3 months prior to participation (no change in bodyweight, i.e. < 3kg).

diabetes mellitus

gastroenterological diseases or major abdominal surgery (allowed i.e.: appendectomy, cholecystectomy)

lactose intolerance and other digestive disorders

cardiovascular disease, cancer, liver or kidney malfunction (determined based on alat and creatinine levels, respectively)

disease with a life expectancy shorter than 5 years

abuse of products (alcohol consumption > 15 units/week, or any drugs)

excessive nicotine use defined as >20 cigarettes per day