Background: Older people need to follow a healthy lifestyle to lead fulfilling lives. This study aimed to investigate the impact of lifestyle education in Iranian medicine on the knowledge, attitude, and behavior of the elderly regarding the reform of nutritional habits in 2022. 
Methods: This research is an interventional study that was conducted on 220 elderly in Fariman, Iran. The subjects were divided into an intervention group and a control group by random cluster sampling. The data collection tool was a researcher-made questionnaire consisting of knowledge, attitude, and behavior assessments related to nutritional habit modification, which was psychometrically validated. Both groups completed the questionnaires at baseline, immediately after the intervention, and at a two-month follow-up. Analysis of the data was conducted utilizing SPSS, software, version 23, with statistical significance set at P<0.05. 
Results: The baseline level of knowledge was not significantly different between the two groups (P<0.001); however, at the 2-month follow-up, there was a significant difference between the two groups (P>0.001). The baseline level of attitude and the 2-month follow-up did not show a significant difference between the two groups (P˂0.001). The baseline level of behavior was not significantly different between the two groups, (P˂0.001); however, at the 2-month follow-up, there was a significant difference between the two groups (P˃0.001).
Conclusion: Changes in the behavior of the elderly two months after the educative intervention were significant, and changing the behavior is the most important goal of educational interventions. Hence, it is recommended to carry out such educational interventions for older adults.