these question: Defining Adult Overweight & Obesity Print Food Assistance and Food Systems Resources Weight that is higher than what is considered healthy for a given height is described as overweight or obesity. Body Mass Index (BMI) is a screening tool for overweight and obesity. Adult Body Mass Index BMI is a person's weight in kilograms divided by the square of height in meters. A high BMI can indicate high body fatness. To calculate BMI, see the Adult BMI Calculator or determine BMI by finding your height and weight in this BMI Index Chart. If your BMI is less than 18.5, it falls within the underweight range. If your BMI is 18.5 to <25, it falls within the healthy weight range. If your BMI is 25.0 to <30, it falls within the overweight range. If your BMI is 30.0 or higher, it falls within the obesity range. Obesity is frequently subdivided into categories: Class 1: BMI of 30 to < 35 Class 2: BMI of 35 to < 40 Class 3: BMI of 40 or higher. Class 3 obesity is sometimes categorized as "severe" obesity. Note: For individuals, BMI is screening tool, but it does not diagnose body fatness