Is there a way to slim your cheeks without any plastic surgery?

Yes: In general, the face will continue to lose its volume as the person ages. In the majority of people the cheeks start to get smaller significantly after the age of 25-35. If the condition of large cheeks is a of hereditary nature, i.e. You parents still have them, then plastic surgery maybe the answer. Good luck from nyc.

Impossible to tell: Without photo or exam, knowledge of your general body habitus, dental condition, family history and health history, we cannot know the underlying cause. Could be obesity, hypertrophy, collapsed dentition, genetics, etc.

Nonsurgical fat loss: Yes! Cool sculpting and mesotherapy (e.g., Kybella) are a number of techniques used to reduce fat without surgery. Lipsuction and laser-assisted liposuction are also minimally-invasive options. I suggest you seek consultation with a board-certified plastic surgeon. Good luck!