SUMMARY Background: Ruffianly behaviour is spreading between Lithuanian children. Ruffianly behaviour include these forms of behaviour – teasing, intimidation, physical spoliation, ostracism, backbiting (gossips), and sexual harassment. Relevancy of this research is that intercommunion between schoolchildren and connection with above-mentioned factors, in Lithuania in not widely investigated problem, in comparison with research of other health risk factors. This problem attracting more attention because of that teasing is reputed factor in teen eating disturbance (bulimia, anorexia). It is been found, that children, who been teased because of their physical appearance (body weight, constitution, clothing), where more depressed, had self-destructive tendency, where more self-contained and had problems of communication. Not objective body weight evaluation is one of factors, witch determinate eating disturbance. Objective: identify objectivity of body weight evaluation and distribution of ruffianly behaviour between Kaunas city schoolchildren and develop dependence specifying the age and sex specific cut off points. Tasks: 1. Define objectivity of bodyweight evaluating; 2. Define ruffianly behaviour distribution between schoolchildren; 3. Define objectivity of bodyweight evaluating and ruffianly behaviour distribution between schoolchildren specifying the age; 4. Define objectivity of bodyweight evaluating and ruffianly behaviour distribution between... [to full text]