Background & Objectives: Overweight and obesity is important not only from physical health aspect but also from psychological, economic, social, and medical costs aspects. Therefore, the present study aimed to investigate the effect of body composition-related feedbacks on physical activity levels, fat percentage, and self-esteem in young girls in 2013.

Methods: The samples were 42 physical education students of Alzahra University who were randomly assigned into 3 groups of real, positive, and negative feedbacks. They participated in pretest-posttest in randomized-groups. In the pre-test and post-test, fat percentage was measured by a body composition analyzer and physical activity levels and self-esteem were assessed using validated questionnaires. Participants’ fat percentage was measured once a week for 3 consecutive weeks and the fat levels were reported; 10% lower and 10% higher than the actual fat percentage to the positive and negative feedback groups, respectively.  However, actual values of fat percentage were reported to the actual group. Analysis of variance and covariance tests were applied for data analysis.

Results: Results showed that positive feedback to increase fat percentage significantly (p<0.05). The type of feedback had no significant effect on physical activity levels and self-esteem.

Conclusion: Positive feedback on body composition can increase fat percentage in young female that may be due incentive effects of positive feedback.