This study aims to provide an overview of evidence on factors affecting Mediterranean diet (MD) adherence across socio-ecological levels (individual, interpersonal and environmental) in Mediterranean countries, which can be target points for future interventions to promote MD adherence.

A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines and registered in the Prospero database (CRD42020189337). Literature was searched in PubMed, Web of Science and PsycINFO.

The MD is one of the healthiest dietary patterns, reducing risk of chronic disease while promoting better health outcomes. However, adherence to the MD remains challenging, even in Mediterranean countries.

Healthy adults aged 18 years and older, living in a Mediterranean country.

A total of thirty-seven cross-sectional studies were included, with 190 to 13 262 participants. Most studies (30/37) were conducted in European Mediterranean countries, primarily Italy (n 14), Spain (n 9) and Greece (n 6). All studies involved community-based samples; two studies included only women. Individual-level determinants were the most frequently examined. Higher socio-economic status, regular breakfast consumption, being unemployed, a job seeker or retired were linked to better MD adherence. Socio-cognitive and interpersonal factors were underexplored. At the environmental level, COVID-19 confinement boosted adherence, whereas the effects of economic crises were inconsistent. Effect sizes were mostly very small to small, and findings are based on low-quality studies.

This systematic review highlighted several socio-economic and environmental factors potentially influencing MD adherence. However, more robust research is needed to better understand socio-cognitive and ecological factors.

To evaluate the reliability of alcohol consumption measured by five different dietary methods in the Catalan Nutrition Survey (1992–1993).

The different questionnaires used were: (1) two 7-day food records, (2) five items addressing alcoholic beverages in a 76-item food-frequency questionnaire, (3) a 1-week recall of 13 alcoholic beverages, (4) a 13-item alcoholic beverages frequency questionnaire and (5) two 24-hour recalls.

Ninety-three of the 120 adults (aged 20 to 70 years) initially recruited completed the questionnaires and provided a peripheral blood sample.

Mean daily alcohol intakes as assessed by the questionnaires were very similar. Beer was the alcoholic beverage most frequently consumed, followed by wine and liquor. Eighty-two per cent of the study population consumed less than 20 g of alcohol per day. No biochemical parameters were significantly correlated with alcohol intake estimated from the questionnaires.

We found a satisfactory level of reproducibility and validity in the pattern of alcohol consumption across different levels and types of alcoholic beverage intake. We also found that the self-administered 13-item questionnaire and the 1-week recall were the best techniques to measure moderate or low alcohol consumption, suggesting that the two methods are the most suitable to assess overall alcohol intake in the general population.