The Mediterranean Diet (MedDiet) is considered an Intangible Cultural Heritage by UNESCO; it is also the world's most evidence-based eating pattern for promoting health and longevity. This study aims to investigate consumer segmentation based on consumption patterns and identify barriers to adherence to MedDiet. Data were collected in 2020 by telephonic survey based on PREDIMED, using a quota sampling technique by socio-demographic variables, such as gender, age, and regional representation of the Portuguese population. The final sample was composed of a total of 1000 respondents. The main results show that regardless of the awareness of the MedDiet (62%), Portugal witnessed a loss of the traditional MedDiet, with the exception of the stand-out statistic that 95% of respondents still use of olive oil as the main culinary fat. Five segments were identified: (1) MedDiet lifestyle followers (11%), (2) olive oil lovers (20%), (3) low-sugar diet foods seekers (11%), (4) healthy and balanced diet seekers (28%), and (5) low-fat diet foods seekers (30%). The main barriers to adhering to the MedDiet include lack of knowledge about the MedDiet, education level, financial comfort, and specific food preference, which by segment are: (1) being passionate about soda drinks, (2) an excess of sweets, (3) low level of pasta consumption, and a (5) lack of fruit, vegetables, and legumes. Segment (4) holds a leading position in MedDiet adherence. The main obstacle to consuming fish is its high price, taste, and challenges in cooking it. When it comes to bread and oleaginous nuts, the belief that these foods are "fattening" reduces consumption. Results help to tailor education strategy and increase adherence to the Mediterranean lifestyle.