Aim Events of context marked by an increased capacity for some sort of change, such as living a healthier lifestyle, are known as "teachable moments" (TM) and commonly occur during or after a significant health event. In this context, the COVID-19 pandemic may constitute a potential TM for lifestyle change. Thus, this study aimed to investigate whether the COVID-19 pandemic could be a TM for a healthier lifestyle and to examine potential predictors for intention to change lifestyle behavior.Subject and methods This is a cross-sectional online survey study, conducted between June 25, 2021, and July 30, 2021, using the Google Forms (R) platform. The survey included questions related to sociodemographic and clinical characteristics. Participants were asked to report their sex, age, weight, height, race, educational level, hometown, family income, comorbidities, COVID-19 diagnosis, smoking habits, alcohol consumption, and physical activity. Data analyses were conducted using SPSS version 20.0, and the significance level was set at p < 0.05.Results Overall, we showed that more than 30% of our sample had high intentions to improve general lifestyle, dietary habits, sleep quality, and physical activity behavior as a consequence of the COVID-19 pandemic. The strongest predictors of higher intentions to change health behaviors with the pandemic were individuals with (a) COVID-19 diagnosis with hospitalization, for alcohol consumption (OR = 8.82, 95% CI: 1.67 to 46.49, p = 0.01); (b) higher affective response, for sleep quality (OR = 1.20, 95% CI: 1.07 to 1.36, p < 0.01); (c) NCD COVID-19 risk, for general lifestyle (OR = 1.40, 95% CI: 1.00 to 1.96, p = 0.04); (c) older age, for alcohol consumption, dietary habits (OR = 1.02, 95% CI: 1.01 to 1.03, p < 0.01), and general lifestyle (OR = 1.02, 95% CI: 1.01 to 1.03, p < 0.01); (e) female gender for dietary habits (OR = 1.55, 95% CI: 1.14 to 2.11, p < 0.01); and (f) higher affective response for physical activity (OR = 1.20, 95% CI: 1.06 to 1.37, p < 0.01).Conclusion In our study, more than a third of healthy adults had higher intention to improve general lifestyle, dietary habits, sleep quality, and physical activity behavior as a consequence of the COVID-19 pandemic.