Body Mass Index

BMI is a number calculated from a person's weight and height.It is a reliable indicator of body fatness for most people Weight categories for health problems are now calculated using BMI.It gives an account of how healthy a person based on his weight and height. But it does not measure body fat. Thus due to its ease of measurement and calculation, it is the most widely used diagnostic tool to identify weight problem within a population including: underweight, overweight and obesity. Though it was invented between 1830 and 1850, BMI became popular during the early 1950s and 60s as obesity started to become a major problem in the Western societies. It can be calculated by dividing the individual's body weight by the square of his or her height. It can also be determined using a BMI chart. BMI chart displays BMI as a function of weight (horizontal axis) and height (vertical axis) using contour lines for different values of BMI or colours for different BMI categories. However, BMI has become controversial because many people, including physicians, have come to rely on its apparent numerical authority for medical diagnosis, contrary to its original purpose,which was to use it as a simple means of classifying sedentary individuals with an average body composition. It is reported that a BMI of 18.5 to 25 may indicate optimal weight; a BMI lower than 18.5 suggests the person is underweight while a number above 25 may indicate the person is overweight.