Study: NCT05709600

Intervention type: DIETARY_SUPPLEMENT
Group type: ACTIVE_COMPARATOR
Intervention: Fasting mimicking diet
Description: Intermittent fasting with human fasting mimicking diet (Prolon®) will be performed for five days prior to living kidney donation in the donor. Prolon® a plant-based diet designed to attain fasting-like effects while provide providing both macro- and micronutrient. Each participant will obtain Prolon® diet during the first visit and the diet will stored at the participant's home at room temperature. Additionally, the participant will receive a food plan for the exact consumption of the diet. Regular phone with a predefined standardized questionnaire will be used to determine each participant's well-being, as well as his or her dietary adherence. Furthermore, the participants will be asked to write down each consumed food items they are consuming in diet-book, which is handed to them during the first visit.~The participants are only allowed to consume water, coffee or tea without sugar simultaneously to the Prolon® diet.

Intervention type: DIETARY_SUPPLEMENT
Group type: ACTIVE_COMPARATOR
Intervention: Ketogenic diet
Description: Isocaloric, ketogenic diet will be performed for seven days prior to living kidney donation in the donor.~The ketogenic diet is based on the KetoCal 4:1 formula diet (Nutricia Milupa GmbH, Erlangen, Germany). Main fat sources are plant oils including palm oil and sunflower oils. The formula diet is provided as a powder that has to be mixed with water before use. To avoid a shortage in protein uptake supplement formula diets K-AM and Fortimel® (both Nutricia Milupa GmbH, Erlangen, Germany) will be used additionally. Salt uptake will be standardized employing either broths or salt tablets to not interfere with the steady-state salt and water homeostasis. A salt ingestion of 5g/day, which is common for western diets, is aimed at. The participants will receive a daily food plan by the dietetics at the University Hospital of Cologne to ensure standardized food consumption

Intervention type: DIETARY_SUPPLEMENT
Group type: ACTIVE_COMPARATOR
Intervention: Dietary restriction of sulfur containing amino acids
Description: Isocaloric, dietary restriction of sulfur containing amino acids will be performed for seven days prior to living kidney donation in the donor.~A dietary restriction of sulfur containing amino acids without restriction in protein uptake will be achieved by following the X Met X Cys Maxamaid formula diet (Nutricia Milupa GmbH, Erlangen, Germany). The formula diet is provided as a powder that has to be mixed with water before use. A minimum of methionine and cysteine uptake (10% of the common uptake per day) will be achieved by consuming individuial calculated amounts of the Fortimel® formula diet (Nutricia Milupa GmbH, Erlangen, Germany). To avoid a restriction in fat and energy uptake additionally the Calogen and Duocal formula diets (both Nutricia Milupa GmbH, Erlangen, Germany) will be used. A salt ingestion of 5g/day, which is common for western diets, is aimed at. The participants will receive a daily food plan to ensure standardized food consumption.

Intervention type: DIETARY_SUPPLEMENT
Group type: ACTIVE_COMPARATOR
Intervention: Control Group ( healthy, low-fat, moderate protein and high carbohydrate diet)
Description: Participants in the control group will be instructed to adhere to a healthy, low-fat, moderate protein and high carbohydrate diet as described in current nutritional recommendations. The control diet will be based on the formula diet Fortimel® (Nutricia Milupa GmbH, Erlangen, Germany). Salt uptake will be standardized employing either broths or salt tablets to not interfere with the steady-state salt and water homeostasis. A salt ingestion of 5g/day, which is common for western diets, is aimed at.