Chubby cheeks on people with normal weight or mildly overweight is a physical finding commonly caused by enlarged buccal fat pads. Buccal fat pads are distinct pockets of fat located in the lower anterior portion of the face (cheeks). When these buccal fat pads are enlarged, they make the face look rounder, chubby, less angular, and sometimes childish.
Enlarged buccal fat pads often run along with family members (they are inherited). Certain ethnic groups (e.g., Asians) are prone to present chubby cheeks.