(1) General characteristics
To identify the general characteristics including body measurements, each respondent's gender, grade, height, weight, number of hours spent on computer at a time, amount of time spent on smartphone, number of hours spent watching TV daily and school credit were collected.
(2) Dietary habits and frequency of processed food consumption
The questionnaire used here referred to the Korea National Health and Nutrition Examination Survey[5] and was adapted for the purpose of this research prior to the preliminary survey with the children and revision.
(3) ADHD(Attention Deficit Hyperactivity Disorder)
The present study used the ADHD diagnosis scale defined in the Diagnostic and Statistical Manual of Mental Disorder-Ⅳ(DSM-Ⅳ 1994). So, Noh, Kim, Ko and Koh[6] investigated the reliability and validity of the research with elementary students, and reported an internal consistency of Cronbach α= .77-.89. The reliability of the present research is Cronbach α= .89.