The CARBFUNC study is a 2-year randomized controlled trial that started in January 2018. 194 obese men and women have been randomized to one of the following three planned isocaloric, normocaloric eating patterns:
1) A semi-whole-grain flour-based diet with 45 energy percent (E%) carbohydrates, in line with official dietary recommendations
2) A diet with 45 E% carbohydrates based on minimally processed whole foods
3) A 8 E% carbohydrate diet based on minimally processed whole foods
All diets consist of 17 E% from protein and 2000 kcal for women and 2500 for men.
The primary outcome measure in the study is change in intra-abdominal ("visceral") fat mass measured by computed tomography (CT) imaging. Visceral fat mass strongly correlates with risk of common diseases such as type 2 diabetes, cardiovascular disease and cancer. Secondary outcome measures include postprandial levels of insulin and lipids, to determine whether different diets produce different metabolic adaptations and hence different responses to the same meal. Postprandial responses can indicate risk of type 2 diabetes and cardiovascular disease. Other outcome measures are gut microbiota composition and function, psychological and social determinants of fat loss and/or compliance.
The trial is registered at ClinicalTrials.gov: https://clinicaltrials.gov/ct2/show/NCT03401970