Introduction:

The COVID-19 pandemic has impacted diet quality in different ways. In this context, community, organizational and consumer nutrition environments can influence the eating pattern.

Objetive:

The purpose of this study was to identify how quarantine during the COVID-19 pandemic changed the diet in Brazil.

Materials and methods:

A natural experiment organized into experimental (social-isolated group - SIG) and control groups (non-isolated group - CG) was conducted with data collection from an online survey at the beginning of the pandemic (T0) and in the less restrictive period of 2020 (T1). Pre-post improvements in diet quality (IDQ) were determined for the SIG and CG. Intra-intergroup changes were tested using the Mann-Whitney and Wilcoxon signed rank tests. The intervention effect was estimated using crude and adjusted difference-in-differences in multilevel regression analysis accounting for repeated measures.

Results:

A sample of 565 Brazilian adults answered the questionnaire at T0 and T1. IDQ was favored twice or more by attitudes such as buying food directly from farmers/street markets, reducing asking for food delivery, and increasing time spent on eating activities and the frequency of cooking. The isolated group had no IDQ at T1, whereas the no isolated group, who worsened diet quality (6.1%) at T0, improved it at T1 (4.8%).

Conclusion:

The restrictive quarantine forced the non-isolated population to have an experience comparable to a food desert, negatively affecting their diet.