1. Department of Human Nutrition, Inst. of Nutrition, University of Jena, Jena, D-07743, Germany
2. Department. of Clinical Nutrition, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, D-14558, Germany
3. Department of Nutritional Toxicology, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, D-14558, Germany
4. Department of Molecular Medicine, University of Ulm, Ulm, D-89081, Germany
5. Department of Internal Medicine I, University of Ulm, Ulm, D-89081, Germany
6. Department of Experimental Diabetology, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, D-14558, Germany
7. Stable Isotope Group, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, D-14558, Germany
8. Department of Endocrinology, Diabetes and Nutrition, Charité University Medicine, CBF, Berlin, D-12203, Germany
9. Max-Planck-Research Group on Stem Cell Aging, University of Ulm, Ulm, D-89081, Germany