Background and Objective: Obesity is a serious problem threatening public health. It is an important risk factor for many pulmonary diseases, and a significant cause of mortality among people. Therefore, it seems that obesity and the % of body fat are associated with respiratory problems. The present study was undertaken to examine spirometric parameters in obese female students at middle school, compared to normal weight. The data were analysed by post hoc test  ( LSD).
Subjects and Methods:   Two hundred and eighty three students from middle school students in Isfahan (aged 12.79±0.88, with body mass index of 39/3±20 Kg/m²) were selected in a cluster random way and were categorized, based on the percentile body mass index (CUT OFF, BMI) and age, into three groups of obese (n=50) with a percentile of 95≥BMI, overweight (n=62) with a percentile of 85≥BMI≤95 and optimal weight (n=171) with a percentile of 15≥BMI≤85. Spirometric parameters were measured using spirometric model of Jager.
Results: Least significant difference post hoc test results also
showed that lung function in normal students was greater than overweight and obese students.
Conclusion: Results showed that obesity particularly influences pulmonary function and significantly decreases pulmonary capacity and volume. However, its exact mechanism is not well-understood and requires further elaborative studies.