Body Mass Index (BMI) assesses body weight in relation to height for measuring a healthy weight range. It is calculated by dividing weight in kilograms by height in centimetres (kg/cm).

A higher BMI indicates a patient is more overweight or obese.

Candidates for bariatric surgery typically have a BMI of 35 and over or those with BMI 30 and over with associated medical conditions such as diabetes or hypertension.