Why is your bmi 15.1 well im not skinny but frinds say fat?

Your BMI may be 15.1 because you have a small frame or a light build, which means that you naturally weigh less than someone of the same height who has a larger frame or a heavier build. Additionally, your friends may be used to seeing people who are of a heavier weight, so they may perceive you as being fat by comparison. It is important to remember that everyone's body is different and that there is no one "ideal" body type. What is healthy for one person may not be healthy for another. If you are concerned about your weight, it is best to talk to a healthcare professional who can assess your individual situation and provide you with guidance.