Hai, it is very common but rare condition. The body's levels of
testosterone and estrogen can, in certain cases, become unbalanced, causing breast tissue to develop in a condition known medically as gynecomastia. If you want to reduce your breast size without drugs or surgeries, make changes to your eating and exercise habits.Follow a diet that is high in foods that are as natural as possible, like fruits, vegetables, seeds, nuts, whole grains, lean meats, fish, beans, and low-fat dairy. To keep your appetite under control, eat small, balanced meals every two to three hours throughout the day. Lean turkey breast on whole-wheat bread with lettuce, tomato, and mustard is an example of a good such meal.ardiovascular exercise helps strengthen your heart and lungs while burning calories. To add to your daily caloric deficit, perform cardiovascular exercise four to five days a week, for at least 30 minutes per session. To place emphasis on your chest muscles, train on an elliptical machine, on which you move foot pedals back and forth as you push and pull hand poles. This is a proven solution for large male breasts. you can try this as you said you decreased so muth then i am sure your body is very much prone to loose body fat.