Cut Down on Carbohydrate Usage in the Diet of Type 2 Diabetes; Mechanisms of Effective Therapy of Diabetes by Selective Choice of Macronutrients. The Hypo-energetic Study.

The present study will be performed as a 6-week randomized fully controlled feeding study, which will address the effect of the hypo-energetic CRHP diet compared with the hypo-energetic CD diet with the macronutrient composition currently recommended to patients with T2D combined with a caloric restriction-induced 5-7% body weight loss on T2D. The study includes n=80 T2D patients.

Measurements include fasting blood samples every 2 weeks during the 6 weeks of the study. Additionally, larger measurement programs will be undertaken at baseline and after 6 weeks, including MRi/s for liver, pancreas and muscle fat content and visceral and subcutaneous adipose tissue; DXA scans for body composition; oral glucose tolerance tests (OGTT); continuous glucose monitoring (CGM); diurnal blood pressure and holter recording. Questionnaires of health-related quality of life, level of physical activity and satiety by visual analogue scale will be performed at baseline and week 6 as well as fecal and diurnal urine sampling.

To ensure a similar body weight loss between intervention groups as well as participants, aimed at 5-7%, caloric intake during the 6 weeks of the study will be hypo-energetic adjusted for each participant according to estimated daily total energy expenditure (TEE). A calculation requiring sex, age, weight and height will be performed to estimate resting energy expenditure (REE), which multiplied with the participant's physical activity level (PAL) will estimate TEE, and thus with an initial caloric deficit of 5% determine the caloric content in the hypo-energetic diet for each participant. Additionally, participants will be weighed twice a week and caloric content adjusted accordingly to ensure a controlled body weight loss.

It is important to recognize that the CRHP diet and the CD diet principally do not differ in the quality of carbohydrate and protein. Thus, this study is unable to address a potential benefit of changes in quality of carbohydrate; however, both diet interventions exhibit a relatively low glycemic index of maximum 55.

Until week 6 diets will be prepared and distributed from the research kitchen of the Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark, to optimize compliance and adherence to the prescribed diet. Following this period and again after approximately 3 months participants will be invited to group sessions with dietician guidance on how to sustain their body weight loss and continue with their assigned diet. A follow-up visit at week 30 will include a blood sample, a spot urine sample and body weight measurement.