<prompt> What should be the value of BMI for it to be classified as obesity?50403020  <response>: BMI stands for the Body Mass Index which is used to predict weight for the respective height. It is defined as the weight in kilograms divided by the square of height in metres and is expressed as kgm2. A value of BMI 30 is classified as obesity and a BMI of 40 is classified under class III obesity. A BMI 20 up to 30 will include those who are pre-obese and the overweight. Ref: Parks Textbook of Preventive and Social Medicine 19th Edition; Pages 332 - 335; 515. 