Feasibility and Acceptability of a New Tool Promoting a Healthy Lifestyle in Liver and Kidney Transplant Recipients

Inclusion Criteria: * Age ≥ 60 years * Liver or kidney transplant received at least 6 months and no more than 25 years prior * BMI between 21 and 29.9 * Signed informed consent * Having a personal smartphone * Stable immunosuppressive therapy in the past 3 months Exclusion Criteria: * Significant weight change (\>5% of body weight) in the past 3 months * Combined liver-kidney transplant * Medical conditions requiring specific diets that may render adherence to the dietary recommendations of the trial unsafe (e.g., chronic kidney disease, inflammatory bowel disease, celiac disease, bariatric surgery, etc.) * General physical conditions deemed by the investigator to contraindicate safe participation in any of the trial activities (e.g., blindness, vertebral fractures, wheelchair dependence, home oxygen therapy, etc.) * Adherence to specific dietary regimens for ethical and/or religious reasons that are incompatible with the dietary recommendations of this trial * Active malignant tumors currently under pharmacological treatment or awaiting surgical treatment (except cutaneous squamous cell carcinomas), or history of malignant tumors within the last 5 years, except for hepatocellular carcinoma * Psychiatric comorbidities deemed by the investigator to potentially compromise safety and/or adherence, thereby risking biasing the results (e.g., schizophrenia, bipolar disorder, eating disorders, etc.) * Changes in glucose-lowering or lipid-lowering therapy during the 90 days prior to the enrollment visit * Active participation in another research or non-research program aimed at lifestyle modification * Any clinical condition, diagnosed or under diagnostic evaluation, that the investigator considers may compromise safety and/or a priori adherence to the intervention, with a potential risk of altering the study outcomes