BMI, calculated by dividing a person’s weight in kilograms by their height in meters squared, has long been used as a shorthand way of assessing a person’s adiposity. In children, high BMIs are associated with cardiovascular disease risks later in life. But, the metric can also be misleading. Because it is based solely on weight and height, it does not distinguish between fat and lean mass. As such, athletes with relatively large amounts of lean muscle mass can easily have BMIs that put them in the categories of having overweight or obesity, while those with little lean mass but high fat mass can still have BMIs in a normal range. BMI also does not tell clinicians anything about body fat distribution, which can be important for health risks. And research has found that the relationship between BMI and adiposity can differ by race and ethnicity. For instance, at the same BMI, Black children tend to have less adiposity than white childre
