The objective of this study was to assess the within-subject longitudinal changes in self-perceived healthy eating attitudes after 10 years of follow-up and to identify predictors of long-term changes in a middle-aged adult cohort.Four thousand five hundred seventy-two participants completed a validated food frequency questionnaire (FFQ) at baseline and after 10 years of follow-up. The FFQ was expanded with a brief 10-item questionnaire about eating attitudes with 2 possible answers: yes or no. A baseline score and a 10-year score were calculated with these 10 items (range from 0 to 10). Participants were categorized into 3 groups according to this score. Linear and logistic regressions were used to examine changes at follow-up and associations between baseline characteristics and improvement in the score.After 10 years of follow-up, a statistically significant favorable change (p < 0.001) was achieved in all questions about eating attitudes, particularly in these items: "Do you try to eat less sweets and pastries?" (12%), "Do you try to eat less meat?" (11.1%), and "Do you try to reduce your fat intake?" (10%). Being female (odds ratio [OR] = 1.19, 95% confidence interval [CI], 1.02-1.39), being 35-50 or ≥ 50 years old (OR = 1.24, 95% CI, 1.07-1.44 and OR = 1.74, 95% CI, 1.38-2.18, respectively), a high level of physical activity (OR for third vs first tertile = 1.20, 95% CI, 1.02-1.41), and a higher Mediterranean diet score (OR for second and third tertiles = 1.18, 95% CI, 1.01-1.37 and OR = 1.26, 95% CI, 1.04-1.52, respectively) were associated with a higher probability of improving the eating attitudes score, while a low body mass index (BMI; OR = 0.71, 95% CI, 0.51-1.00) and snacking between meals (OR = 0.84, 95% CI, 0.73-0.97) were associated with a lower probability of improving their score.The eating attitudes of the participants in the Seguimiento Universidad de Navarra (SUN) cohort became more favorable after 10 years of follow-up. Certain sociodemographic or clinical variables may predict a positive change.