The PROtein enriched MEDiterranean Diet and EXercise (PROMED-EX) randomised controlled trial (RCT) aims to determine the efficacy of a protein-enriched Mediterranean diet, with and without exercise, in comparison with standard care, on nutritional status and cognition in adults at risk of undernutrition with subjective cognitive decline. The project will explore the mechanistic pathways in diet-exercise induced change in nutritional status and cognition.