RESUMEN
The measures implemented to contain the COVID-19 pandemic resulted in both behavioral and lifestyle changes. The "Changes in Lifestyle-Related Behavior" instrument was developed to assess lifestyle-related behaviors in the Indian population. However, considering current knowledge, this instrument was not adapted for the Brazilian population. In addition, the relationship between fear of COVID-19 and consumption of dietary supplements has not yet been evaluated. Thus, we aimed to investigate the relationship between the use of dietary supplements with lifestyle behavior and the fear of COVID-19, as well as assess the psychometric properties of the Brazilian version of the "Changes in Lifestyle-Related Behavior" instrument. An online questionnaire assessed sociodemographic, occupational, anthropometric, physical activity (International Physical Activity Questionnaire-short form), fear of COVID-19, and lifestyle behavior data from 416 Brazilian adults (237 females; 18-60y). Mann-Whitney, Chi-square test, exploratory, and confirmatory analyses were applied. Exploratory and confirmatory analyses showed a satisfactory adequacy level of the questionnaire (CMIN/DF = 2.689; Cronbach's α = 0.60) with 5 domains ('Bad eating behavior'; 'Healthy eating'; 'Sleep quality'; 'Interest in cooking'; 'Number of portions and meals'). Lower fear of COVID-19 scores and higher levels of physical activity were found in participants who reported previous dietary supplement intake during the pandemic; in addition, the group that did not ingest dietary supplements reported greater changes in stress and anxiety levels during the pandemic (p<0.05). The intake of dietary supplements before the pandemic was associated with greater energy expenditure and better coping with the fear of COVID-19 during the pandemic. Additionally, the Changes in Lifestyle-Related Behavior tool can be used to assess lifestyle-related variables during the pandemic.