Nutrition education is crucial for improving nutritional knowledge. This study aims to evaluate the impact of healthy nutrition education on hedonic hunger, adherence to the Mediterranean diet, and self-efficacy for healthy eating among early adolescence. This one-group, pre-test-post-test, quasi-experimental study included 202 middle-school students. Data were collected using a researcher-designed survey that included demographic variables, the Children’s Power of Food Scale (CPOF-S), the Self-Efficacy for Healthy Eating Scale (SEHE-C), the Mediterranean Diet Score (KIDMED), and the Brief Nutritional Knowledge Assessment Form. Anthropometric measurements (weight, height, waist circumference, hip circumference, and neck circumference) were also taken. After the pre-test, each student received two hours of healthy nutrition education. A follow-up survey was administered four weeks later. The study revealed that most early adolescents exhibited unhealthy dietary habits, such as skipping main meals (15.3% all the time and 60.2% occasionally), snacking on sweet treats (33.3%), and having irregular eating patterns (47.4%). Additionally, the early adolescents had higher weights, body mass index (BMI), neck circumferences, and heights compared to reference values (p<0.01). Significant changes were observed post-intervention: lower hedonic hunger scores (beginning: 2.90±0.68, follow-up: 2.70±0.76, p<0.01), decreased self-efficacy for healthy eating (beginning: 5.41±3.50, follow-up: 4.33±3.61, p<0.01), and increased knowledge about healthy nutrition (beginning: 67.23±14.39, follow-up: 80.00±17.22, p<0.01). This study highlighted that healthy nutrition education enhances nutritional knowledge and decreases hedonic dietary tendencies among early adolescents. Continued nutrition education may further improve children’s preferences for healthy foods.