The Clue The "I" of BMI, when measuring body-fat
The Answer INDEX
The "I" in BMI stands for "Index." BMI, or Body Mass Index, is a formula used to assess body fat based on a person's weight and height. It provides a numerical value that helps categorize individuals as underweight, normal weight, overweight, or obese. Therefore, "INDEX" is the correct answer to the crossword clue.