Food waste remains a major problem for the world and food security. Despite the fact that consumers are significant producers of food waste, little research attention has been paid to young people who are in college and living away from the family home. The present study aimed to assess food waste among college students living away from the family home, taking into account the nutritional knowledge acquired during college. In addition, the goal was to compare how nutritional knowledge affects food waste and consumer behavior in the study group. Descriptive statistics were performed on behaviors with food management at home, as well as shopping planning and self-shopping at the store, for the total respondents, students with nutritional knowledge and students without such knowledge. A chi-square test was performed to show whether the field of study influences the frequency of food throwing away and the appropriate management of excess food. Spearman’s rank correlations were calculated for the frequency of food discarding, the frequency and amount of shopping and the field of study. The results indicate that the field of study determined food discarding and appropriate food management (p < 0.05), while it was found that fermented dairy beverages, fruits and vegetables and bread were the most frequently discarded foods in both study groups (p < 0.05). Students with nutritional knowledge were less likely to throw away food compared to students without nutritional knowledge and were better at managing excess food.