The chin area (or "submental region") can be prone to fullness – that is, collecting and holding fat that is often resistant to diet and exercise. Fullness under the chin or the "double chin" is a manifestation of the foundation of the skin, muscle bone and fat, and is influenced by several factors such as aging, genetics and weight gain. It is a common misconception that a double chin only appears in those who are overweight. In reality, it can occur in any body type.