Introduction : There are so many studies associating blood pressure in children and adolescents with body fatness i.e. stating that high body fat is associated with high blood pressure in children and adolescents. The purpose of this study was to determine that which portion of the body mass index, fat or fat free mass index is more influencing the blood pressure in Gujarati Indian adolescents.

Methods : 733 schoolchildren of 10-18 years of both genders were chosen for this study. The body fat percentage and blood pressure were measured and on the basis of body mass and fat mass, fat free mass index and various other indices were calculated. The association of fat mass index and fat free mass index with blood pressure was computed using correlations.

Results : The relationship of BMI with mean blood pressure of boys (R=.326) was more strong than that in girls (R=.149). The blood pressure was having more strong positive correlation with lean body mass index than that with fat mass index in all subjects (R=0.230 versus R=0.184), boys (R=0.285 versus R=0.242), & girls (R=0.179 versus R=–0.081).

Conclusion : Fat free mass index has more strong association with blood pressure than fat mass index in the adolescent population irrespective of gender. However as far as prevention of hypertension is concerned, reducing body fat (rather than only body weight) may remain an important measure to prevent hypertension as body fat mass is reducible while lean body mass may not be reducible and, in long term, obesity itself can lead to hypertension by various mechanisms.