Currently, obesity is considered a pandemic, in addition to the known metabolic changes, structural alterations such as those generated in the ventilatory system occur. However, it has been observed that depending on the form of categorization of this condition, there may or may not be alteration on this system, thus generating a complication when choosing this tool. Therefore, the objective of this study was to compare parameters of lung function in obese individuals and normo-weight according to body mass index (BMI) and body fat percentage (BFP). The ventilatory function was measured in 57 participants, later these variables were contrasted between the subjects normal weight (Nw) and obese (O) according to BMI and BFP. A significant increase in the inspiratory capacity (IC) value of O versus Nw was observed and of the expiratory reserve volume (ERV) and functional residual capacity (FRC) of Nw in relation to O, both for the division by BMI and by BFP. In the group divided by BMI, the variables of specific resistance of the airways (sRaw) and maximal inspiratory pressure (MIP) were significantly higher in the participants O. In addition, specific airway conductance (sGaw) was significantly higher in subjects Nw. In conclusion, the BMI showed greater versatility as a predictor of ventilatory function, however, more studies are needed on the mechanical effects of this indicator and the BFP on the airways.

KEY WORDS: Body mass index; Body fat percentage; Lung function.