Abstract
Background: Childhood obesity is rising at an astonishing rate over the last decade globally making the individual highly susceptible to various diseases. It has transformed into a major public health issues in India. These changes may reduce the compliance of the lungs and the thoracic cavity and increase the load on the respiratory muscles. This may end up with the reduction in lung volumes, especially vital capacity (VC).

Aim and Objective: The aim of the study is to see the effect of body mass index (BMI) on the VC in young adults.

Materials and Methods: This cross-sectional analytical study was undertaken over a period of 12 months in the Physiology Department of Sridev Suman Subharti Medical College on 300 healthy individuals with age of 18–35 years old to determine the baseline anthropometric measurement followed by measurement of one stage VC using a student’s spirometer. Subjects having cardio or pulmonary condition were excluded from the study. Two separate groups were assigned according to BMI normal (Group A) with BMI <25 kg/m2 and obese (Group B) with BMI >25 kg/m2. Mean ± SD of BMI and VC for both groups were calculated.

Results: The VC showed a statistically significant decline in overweight/obese individuals. The mean BMI in Group A (normal) was 20.80 ± 2.28, whereas in Group B (obese) was 29.27 ± 2.77. The mean VC was 3.83 ± 0.84 L in normal BMI group as compared to 4.05 ± 0.64 L in obese BMI group.

Conclusion: The VC showed a compromised status in overweight/obese individuals. This difference can be attributed to the presence of adipose tissue around the ribcage, in the abdomen and visceral cavity loading the chest wall, leading to small airway collapse and subsequent lowering of the VC.

Key words: Body Mass Index; Vital Capacity; Young Adults; Obesity