When everyone in the trend is trying to have a sharp angle cheeks and chin that can cut on something that sharp, here I find someone wanting a chubby cheeks.
Next was it only your cheeks or body weight has decreased? It's normal for male hormone to thicken the skin and make it look bony on ageing from teenage to adult. ( don't blame masturbation for this it has it's own side effects specially psychologically)
Need more information on weight and other habits if you have any, food habits etc to prescribe medicine to improve your overall health which in result can / may give you your desired cheeks.
Next Steps
Take proper knowledge by consulting.
Health Tips
sleep early, wake Early