Body mass index-In Depth

Jack Berkey's picture

Body mass index (BMI) is used for measuring height/weight characteristics in adults and for categorizing them into groups and “allows population data to be collected at regular intervals to estimate the prevalence of overfatness /obesity” (Sports and Exercise Nutrition - Chapter 13). BMI is a person’s weight in kilograms divided by the square of their height in meters (kg/m2) (Obesity and Overweight) A normal weight adult has a BMI of 18.5-24.9. An adult with a BMI greater than or equal to 25 is considered overweight and an adult is considered obese with a BMI that is greater than or equal to 30. For example, weighing 210 pounds with a BMI of 30.1 is considered obese which will ultimately contribute to health issues. While BMI is a measure of an individual’s fatness, it can also be beneficial as it is used to determine risk factors for developing health issues such as cardiovascular disease, diabetes, and some cancers. That said, BMI is not always a perfect indicator for assessing one’s health as bodybuilders typically have higher BMIs but are still considered to fall into a healthy range. It is a useful, easy tool but needs to be evaluated on a case by case basis as it may not mean the same level of fatness across all individuals and is not considered a measure of body composition.