Background: Increasing levels of obesity worldwide have led to a rise in the prevalence of obesity-related complications including cardiovascular disease, diabetes, cancers etc. Health care providers believe that obesity has a negative effect on patients undergoing cardiac surgery, with overweight and obese patients being more likely to experience adverse post-operative outcomes. The body mass index (BMI) is the single most used measure for determining obesity classification in clinical practice, without accounting for a patient's level of cardiopulmonary fitness or muscle mass.