Dietary changes during the COVID-19 pandemic in Polish adults: a systematic review and meta-analysis

Introduction:
The COVID-19 pandemic has strongly influenced the health of populations worldwide and lifestyle behaviors, especially during the lockdown period. This review and meta-analysis aimed to examine dietary changes among Polish adults during the COVID-19 pandemic.

Material and methods:
A systematic review and meta-analysis were conducted based on PRISMA and MOOSE protocols. PECOS criteria were used to define the research question and preliminary inclusion and exclusion criteria – participants: Polish healthy adults (≥ 18 years) following a typical diet; exposure: the COVID-19 pandemic period (from March 2020 to May 2022); comparator: the same population before the COVID-19 pandemic period; outcomes: changes in nutritional behavior. Study design: observational studies, cohort studies, and cross-sectional studies. The articles were identified by searching four electronic databases: Scopus, Web of Science, PubMed, and Polish AGRO Base. Initially, 1226 records were identified in this way. Finally, 21 articles were included in the review (qualitative assessment), and 8 studies were included in the meta-analysis (quantitative analysis).

Results:
The systematic review provides evidence for healthy and less healthy consumer behavior during the COVID-19 pandemic in Poland. The meta-analysis of cross-sectional studies revealed increased food consumption during the pandemic (vegetables, fruits, water, milk, and dairy products), which we rated as beneficial for health. Many Poles did not change their eating behavior during the COVID-19 pandemic, including meat, legumes and pulses, plant oils, and alcohol intake.

Conclusions:
Both positive and negative changes in eating behaviors during the COVID-19 pandemic were observed among adults in Poland. Future studies that assess nutrient intake are important to measure the impact of dietary changes during the pandemic on health status.