Eating disorders and body image concerns are increasingly prevalent issues among young individuals, with medical students being particularly vulnerable due to heightened stress levels. This study enrolled 879 medical students to investigate these concerns. The KomPAN questionnaire was utilized to assess dietary habits and knowledge, the Body Esteem Scale (BES) to evaluate body satisfaction, and The Eating Attitudes Test (EAT-26) to identify eating disorders. A higher level of nutritional knowledge was found to be statistically significantly associated with attempts at excessive calorie restriction among women (β = 0.0864) and negatively among men (β = −0.2039). Moreover, it was negatively associated with self-control of food intake only among men (β = −0.2060). Furthermore, a higher BMI was associated with attempts of excessive calorie restriction in both women and men (β = 0.1052 and β = 0.1656, respectively) and negatively with self-control of food intake (β = −0.0813 and β = −0.1453, respectively). A higher BMI was associated with poorer body esteem across all variables in both genders, except for upper body strength among men. Nutritional knowledge did not correspond with any of these variables, while dietary quality was positively associated with physical condition in women and with physical condition, physical attractiveness, and upper body strength in men. Our study findings suggest that dietary interventions could be improved by considering gender-based behavioral differences and focusing on portion control for individuals with a higher BMI. Caution is warranted in extrapolating the results to the general population due to the specific nature of the study population.