The bottom line is unless the gynecomastia is mostly fat, exercise and or diet will NOT work.
Agreed. However...
Forgive another ignorant post/coment, but I speak from not just experience, but, also, medical evaluations.
On the part of experience, I made a change a year and a half ago, wherein I reduced my fat intake, increased my exercise, and focused on eating a correct and healthy diet. As a result, I lost over 30 lbs., with a very noticeable loss in the gynecomastic area.
Six months ago, I became very ill, enough to the point where I couldn't exercise. I was out for three weeks, which snowballed into where I am now, with my body gaining back all of the lost weight, plus some. There were two areas that showed the most gain: the chest and the stomach, in that order. Only way that could happen (assuming no medical problems) is if it was an addition of fat, which means that my gynecomastia is primarily made up of fat.
On the part of medical evaluations, I was examined by a PS in June, my third PS in 15 years. He told me, flat out, that my gynecomastia was 95% fat. Out of that fat, he estimated that he would be able to remove 85-90% of it through simple liposuction. He made it very, very clear that under no circumstances, even if I were to go to another PS, should I have, nor consider, excision as a necessary option. He said that, with my broad shoulders and muscle layout, I would be an excellent candidate for liposuction. He detected no glandular issues, which means that my gynecomastia is primarily made up of fat.
In addition to the physical examination, I was able to ask him what benefits, when dealing with gynecomastia, could be derived from exercising. He stated that the first areas to show signs of fat loss are the stomach, in men, and the breasts and hips, in women. He stated that those areas show the first signs because they're primarily made up of fatty tissue (female bodybuilders and their traditionally small breasts are an excellent example of fat loss through exercise, since the female breast is primarily comprised of fat cells). As a result, a man who suffers from gynecomastia, CAUSED BY FAT, would see significant decrease with exercise. However, he did stress that it would not 'get rid' of it, and that surgery, specifically to my case, would still be needed.
One more thing must be noted: the PS made it clear that the surgery almost always has better results with a physically fit man, than with one who is out of shape. The skin responds better to contouring, the risk of infection diminishes, and the entire healing process is smoother. He made it very clear that no surgery is risk-free, fit person or not, but that the man who's in shape will nearly always have a better surgical experience than the one who is not.
When I post a comment, not only do I post it from personal experience and observation, but, also, from medical evaluations and advice. My comment on exercise was correct: when dealing with liposuction for a gynecomastic condition that's comprised of mostly fatty tissue, a precursor of exercise, healthy eating, and fat loss will not only have a direct impact upon the condition itself, but will prepare the patient for a recovery that should be faster, less painful, and show better results.
Exercise will NOT get rid of gynecomastia, fat or glandular, but it will definitely help.
I just wanted to be clear on where I stand. I'll always value the input and opinions of others...