Chin fat, sometimes unfortunately known as a “Double Chin”, refers to the fat just underneath your chin, and it can sometimes extend to the sides under your jawline. Chin fat can be the result of either weight gain, genetics, age or hormonal changes. Chin fat is often stubborn and doesn’t go away with just diet and exercise. It can become frustrating if we eat a healthy diet and exercise regularly and we still don’t see the shape we are aiming for.