ObjectivesCoronavirus disease 2019 (COVID-19) emerged and rapidly spread worldwide. Several countries have imposed lockdown and isolation in attempt to mitigate viral spread. However, social isolation has a negative effect on psychological aspects, increasing stress, fear, anxiety, anger and emotional disturbance, as well as affecting sleep pattern and the practice of physical activity. Negative emotions and lifestyle changes trigger overeating, consequently affecting dietary practices. The aim of this study was to verify the prevalence of lifestyle factors (i.e., sleep time/quality and practice of physical exercise), eating behavior dimensions, chronotype, and association with dietary practices (planning, domestic organization, food choice, ways of eating) in home confinement during the COVID-19 pandemic in São Paulo, Brazil. MethodsThis cross-sectional study was conducted between April 27 and May 25, 2020. An anonymous online questionnaire (Microsoft Forms) was used for data collection by the snowball method. We verified dietary practices (outcome), eating behavior, physical exercise practice, sleep quality and duration, and chronotype (exposure variables). Sex, age, educational and social status were assessed as covariates and confounders. We evaluated 724 adults (585 women and 139 men). Mean age was 32.6 y (±11.3) for women and 33.5 y (±10.5) for men. ResultsEmotional eating (EE) and binge eating (BE) were positively correlated (r = 0.66; P <0.001). Dietary practices were negatively correlated with BE (r = –0.41; P <0.001), EE (r = –0.33; P <0.001) and body mass index (r = –0.24; P <0.001). Linear regression demonstrated that EE (β = –0.1351; t = –2.841; P = 0.005; ηp2 = 0.013), BE (β = –0.2580; t = –5.612; P < 0.001; ηp2 = 0.050), no practice of physical exercise at home (β = –0.4271; t = –5.933; P < 0.001; ηp2 = 0.055), being vespertine (β = –0.3435; t = 2.076; P = 0.038; ηp2 = 0.019), and age (β = –0.082; t = –2.210; P = 0.027; ηp2 = 0.008) are negative predictors of dietary practices. Finally, cognitive restraint (β = 0.1407; t = 3.858; P < 0.001; ηp2 = 0.024), better sleep quality (β = 0.1768; t = 2.506; P = 0.012; ηp2 = 0.010), receiving 4–10 wages per month (according to a minimum wage in Brazil that corresponds to US $ 183.01) (β = 0.2568; t = 2.573; P = 0.10; ηp2 = 0.027) and 10 – 20 wages per month (β = 0.4490; t = 3.726; P < 0.001; ηp2 = 0.027) are positive predictors of dietary practices. ConclusionEating behavior, physical exercise, sleep, and social factors can be important predictors for dietary practices during COVID-19 social confinement. Longitudinal studies in Brazil are needed to confirm these findings.