Background <p>The aim of this study is to increase the attitude and knowledge levels of older adults living in a Social Life Campus about healthy nutrition after ‘Healthy Nutrition’ training, to reflect it on attitude and to improve older health.</p> Methods <p>This experimental study utilized a Solomon four-group design and was conducted with a total of 69 older adults, divided into two experimental groups of 30 individuals and two control groups of 39 individuals. Participants were healthy older adults without psychological or neurological illnesses, capable of effectively receiving education. They volunteered for the training program and were administered the measurement tool.</p> Results <p>The dependent sample t-test results showed a significant difference in the pre-test and post-test scores of the Healthy Nutrition Attitude Scale in the experimental group (pre-test mean = 3.20, SD = 0.45; post-test mean = 4.10, SD = 0.30), ( t = -8.832, <i>p</i> = 0.001), but not in the control group (pre-test mean = 3.50, SD = 0.40; post-test mean = 3.51, SD = 0.42), (t = 0.123, <i>p</i> = 0.903). Similarly, the Nutrition Knowledge Scale showed a significant difference in the experimental group (pre-test mean = 2.50, SD = 0.35; post-test mean = 3.10, SD = 0.32), (t = -10.175, <i>p</i> = 0.001), but not in the control group (pre-test mean = 2.15, SD = 0.25), (post-test mean = 2.17, SD = 0.20; t = -1.888, <i>p</i> = 0.074).</p> Conclusions <p>This study demonstrates that the Healthy Nutrition Education Program significantly improves the nutritional knowledge and attitudes of older adults, promoting healthier eating habits. The program’s structured design highlights its potential for adaptation and implementation in health promotion initiatives targeting similar elderly populations.</p> Trial registration <p>This trial was registered at ClinicalTrials.gov with the ID NCT06544031 on August 9, 2024.</p>