INTRODUCTION The impact of confinement on eating habits has been associated with mental health, gender, and socioeconomic status. This study examined the consumption of sugar-sweetened beverages and fast food during the COVID-19 confinement period in Chile, a country with a history of high consumption of processed foods. METHODS A cross-sectional design was done from responses obtained through an online survey between May and August 2020. Data were collected and managed using the SurveyMonkey® electronic tool (hosted at the Institut d'Investigació en Atenció Primària (IDIAP) Jordi Gol i Gurina, Barcelona, Spain). We recruited through online platforms and social networks using convenience and snowball sampling. People aged 18 years and older were included. The consumption of sugar-sweetened beverages and fast food was analyzed in relation to socioeconomic and sociodemographic variables. Logistic and log-binomial regression models were evaluated using Stata v18. P<0.05 was considered statistically significant. RESULTS 6971 (93%) people completed the questionnaire. The participants were predominantly born in Chile (94.6%), with a majority being women (63.5%) and under 50 years old (74%). The prevalence of consumption of sugary drinks and fast food was 15.4% (men, 14.6%; women, 15.9%) and 19.6% (men, 17.2%; women, 21%), respectively. Age 40 years and older was a protective factor for both women and men. Factors associated with the consumption of sugar-sweetened beverages included a change in employment status (prevalence ratio 1.26; 95% confidence interval 1.02 to 1.45) and, for fast food consumption, being female (1.18; 1.06 to 1.32). CONCLUSIONS Sex, age, and change in income were associated with increased consumption of sugar-sweetened beverages and fast food during the COVID-19 pandemic. These results reaffirm the importance of implementing social and communicational strategies that promote healthy eating, especially during health emergency scenarios.