Usability and Feasibility of the NutriQuest Application

Inclusion Criteria: * History of cardiovascular disease with or without intervention (PCI/CABG/conservative/pacemaker implantation/ablation) * History of current or past cardiac rehabilitation in Jessa Hospital Hasselt * Current treatment must require them to follow the Mediterranean diet plan * Age ≥18 years * Willing and physically able to follow a application-based healthy nutrition program and other study procedures in a six-week follow-up period * Evidence of a personally signed and dated informed consent, indicating that the subject (or a legally-recognized representative) has been informed of all pertinent aspects of the study * Possession of and/or able to use an Android based smartphone (version 6 or higher) * Possession of internet connectivity * Dutch speaking and understanding Exclusion Criteria: * Pregnant females * Combined with diabetes or severe kidney disease * Participation in other cardiac rehabilitation program trials, focusing on diet outcome * Current or recent participation in other technology-supported programs, even when not directly targeting nutrition * Any condition which in the opinion of the investigator would make it unsafe or unsuitable for the patient to participate in this study or a life expectancy of less than six weeks based on investigators judgment