Fluctuations in Mediterranean Diet Adherence Pre- and Post-Pandemic: A Study of Portuguese Cohorts 2019-2024.

Abstract

The Mediterranean Diet (MD) is a lifestyle offering numerous health benefits. Nevertheless, the adherence to the MD is moderate even in Mediterranean countries. While sociodemographic factors influence MD adherence, additional impacts occurred due to the COVID-19 pandemic. This cross-sectional longitudinal study with three cohorts of Portuguese adults analyzes MD adherence before, during, and after the COVID-19 pandemic, and explores the effect of sociodemographic variables. Sociodemographic factors, lifestyle habits, and MD adherence were assessed in the years 2019, 2021, and 2024 with an online self-filled questionnaire. MD adherence was measured with the Mediterranean Diet Adherence Screener (MEDAS). MEDAS score increased significantly (p < 0.05) from 2019 to 2021 (6.2 ± 0.7 to 7.7 ± 0.1), followed by a significant (p < 0.05) decrease in 2024 (7.2 ± 0.1) relative to 2019, which was more pronounced in participants with higher income. Accordingly, a trend in healthier food choices was observed followed by a decline in 2024. Of note is the significant increase in red meat consumption (p < 0.05) in 2024 relative to 2021. Respondents who consumed more red meat were mostly men, employed, or in a stable relationship. Most respondents practiced sport "Never or occasionally" in 2019 and 2021 (59.4 and 55.2%, respectively); in 2024, this category was significantly (p < 0.05) reduced (40.9%); men or higher-income participants were more likely to meet the recommended activity levels. This study reveals that the improvements in MD lifestyle during the pandemic were not sustained in 2024, as healthier habits formed during confinement were not fully integrated into long-term behavior. These findings strengthen the need for targeted public health interventions to promote the MD.