Body mass index (BMI) is a measure of body fat based on height and weight. Typically, women believe that they look their best at values between 20 to 22 and men are usually satisfied with a BMI of 23 to 25. If your BMI is between 17 to 22, your life expectancy is longer than average. If your BMI is between 23 and 26, you are not considered overweight by most people. Alli Weight Loss Treatment is designed for people who have a BMI of 28 or higher. Discover your BMI using the graph below to determine if Alli is suitable for you.