Indonesia is still being challenged by nutritional problems, both under and over nutrition. The availability of various unhealthy food with attractive packaging combined with misconception of balance diet as 4 sehat 5 sempurna , might contribute to situation. This study aims at evaluating effectiveness of IEC strategy in changing knowledge, attitudes and practice regarding behavior diet among elementary school communities. The study design is a before and after, located at 2 public schools in depok, with 132 students grade 4 and 5 and their mother. Qualitative approach as well as baseline and endline surveys were used. Most students and their parents considered that balance diet is 4 sehat 5 sempurna. This knowledge was originated from their teachers teaching media. The teacher's knowledge was based on school reference book. Intervention has improved students main knowledge and attitude. While some pratices have improved there are others still need to be improved. It is concluded that IEC intervention is potential to change KAP of students. Teachers need to be supported by correct reference book to be in line with what they are teaching.