BACKGROUND: Obesity among adults is a significant public health problem. Diet quality might be influenced by eating behavior and is associated with nutritional status, but research is lacking in obese adults in Indonesia. AIM: The purpose of this study was to investigate the relationship between eating behavior, diet quality, and obesity. METHODS: A cross-sectional study was carried out among 144 respondents (39.6% males and 60.4% females), aged 39.07 ± 5.48 years, who were selected using stratified random sampling from five subdistrict in Malang City, East Java, Indonesia. The eating behavior score was calculated using the Dutch Eating Behavior Questionnaire (DEBQ) and the diet quality using the Diet Quality Index International (DQI-I) from SQ-FFQ. Association of eating behavior, diet quality, and nutritional status was analyzed using logistic regression analysis. RESULTS: The study showed that the prevalence of obesity among female adults was higher (31.9%) than males (18.8%). The female participant had a two-fold higher likelihood of being overweight or obese than the male participant (OR = 2.25, 95% CI: 1.077; 4.071, p < 0.05). The average diet quality score was 57.99 ± 7.26 or 80% from a total score of 100. There was no significant difference in total DQI-I and component scores, including variety, adequacy, moderation, and overall balance across nutritional status and sex, p > 0.005. The poor-diet quality was higher in the overweight and obesity group (43.75 %) than the normal group (16.67%). There was a statistically significant difference of restrained eating with overweight and obesity status (p < 0.05) with OR 2,652 (CI 95% 1.149; 6.119) and female (OR 2.496, CI 95% 1.195; 5.212, p < 0.05). CONCLUSIONS: It can be concluded that obesity was prevalent in female adults, and there is a relationship between obesity and restraint eating among adults. Future studies should examine the causal effects of eating behaviors on quality diet and in the development of obesity.