Introduction & Objective : Many studies carried out about breast feeding and its relationship with overweight and obesity. In some of these studies the incidence of overweight and obesity in breast fed babies has remarkably decreased, but some other studies have rejected the positive effect of breast milk on decreasing the incidence of overweight and obesity. Considering these contradictions we decided to do a study about this subject on primary school children in Hamadan.

Materials & Methods : 1400 students were included in the study and the way of feeding them in the first 6 months of their life and their present weight and height were recorded in the check list.

Results : In this study 89 children were overweight (6.4%) and 80 children were obese (5.7%). When we compared overweight and obesity in the breast fed group with the non breast fed group, we indicated that overweight and obesity in breast fed babies were 6.1% and 4.8% respectively, whereas in non breast fed babies it was 7.5% and 9.7% respectively.

Conclusion: We concluded from comparing these data , that the incidence of overweight and obesity in breast fed babies was much less than non breast fed babies and the difference between them was statistically meaningful (Pv=0.004).