The purpose of this study was to evaluate the impact of a community-based food education program on nutrition-related knowledge in middle-aged and older patients with type 2 diabetes (T2D). Participants (n = 36; 65.9 ± 6.0 years old) were recruited in primary health care to a 9-month community-based lifestyle intervention program for patients with T2D and randomly assigned to an exercise program (control group; n = 16) or an exercise program plus a food education program (experimental group; n = 20). Nutrition-related knowledge was assessed through a modified version of the General Nutrition Knowledge Questionnaire. The increase in total nutrition-related knowledge score and sources of nutrients area score was significantly higher in the experimental group compared to the control group. No significant changes in nutrition-related knowledge were found between groups in dietary recommendations and diet-disease relationship areas, although improvements were observed. This community-based food education program, with the use of easy to implement strategies (short-duration lectures and dual-task problem solving activities during exercise), had a positive and encouraging impact on nutrition-related knowledge in middle-aged and older patients with T2D.