This study aimed to associate Eating Competence (EC) with food consumption and health outcomes in the Brazilian adult population. Researchers developed a questionnaire to associate EC with sociodemographic information, health outcomes, and food consumption. Data on body weight and height was referred to by participants in the questionnaire, and body mass index (BMI) was calculated and classified. A question to evaluate the perception of body size was included. After constructing the questionnaire items, content validation and semantic evaluation were performed following the Delphi method with a group of judges composed of 26 health professionals. The judges evaluated the sociodemographic information, health outcomes, and food consumption items associated with the eating competence instrument (previously validated in Brazilian-Portuguese). The final version of the questionnaire was composed of 33 items. Our results confirmed good reliability, responsiveness, and internal consistency. A total of 1810 Brazilians answered the questionnaire. Most of the participants were female, up to 40 years old, with a high education level and high income. Most of the participants did not report diabetes or hypertension. The EC total score did not differ among males and females. Individuals up to 40 years old presented a lower total score. The increase in educational level and income also increased EC total score. Excess weight individuals showed lower EC compared to the normal weight/underweight. Individuals who consumed fruits and/or vegetables five or more days/week presented the best scores for total EC.