BMI (body mass index) is a calculated number representing a person's level of fat or obesity level. According to the Centers for Disease Control and Prevention (CDC), a BMI of 30 or above indicates obesity. BMI levels are broken down by weight range and are as follows:
BMI < 18.5 is underweight
BMI 18.5-24.9 is normal weight
BMI 25-29.9 is overweight
BMI 30-39.9 indicates obesity
BMI >40 indicates morbid obesity