The impact of obesity on parameters of respiratory physiology

Expiratory reserve volumeReduction
Functional residual capacityReduction
Total lung capacityReduction (only in the morbidly obese)
Vital capacity/forced vital capacityMild reduction
Forced expiratory volume in 1 sMild reduction
Maximal expiratory flow at 25–75% of forced vital capacityReduction
Diffusion capacityReduction/no change/increase
Respiratory muscle strengthNo change
Respiratory muscle enduranceReduction
Airway resistanceIncrease
Airway reactanceIncrease
Neural respiratory driveIncrease