Objectives:To determine the effects of a school-based nutritional program (SBNP)designed for adolescents in high school, who are for various reasons unable to eat amidday meal, on their anthropometric measurements, blood test results and eatinghabits.Patients and Methods:The research used one group and was of a pretestposttestdesign. 148 adolescent high school students who had difficulty accessinga midday meal and expressed willingness to participate in the study. As part of theSBNP, four sessions of nutrition education, each for one hour once a week, wereheld and the students were regularly provided with lunch at school for 3 months. Asociodemographic form, an “Eating Habits Inventory,” anthropometric measurementsand blood tests.Results:Mean waist measurements were significantly lower at the last evaluationcompared to the preliminary assessment. The increases in Rbc, Hb and Htc afterthe SBNP compared to pretest results were found to be statistically significant. Mouthsores, gingival bleeding and hair loss rates showed a significant decrease.Conclusion:The SBNP had a positive impact on increasing erythrocyte, hemoglobinand hematocrit counts and reducing waist circumference measurements. In addition,the SBNP also contributed to reducing certain skin and mucosal conditions (sores onthe edges of the mouth, canker sores, gingival bleeding) and the hair loss rates that maybe associated with vitamin deficiency. It is recommended that the impact of an SBNP betested for a longer duration with a larger sample that includes a control group.