Why do some males have breasts
Male breasts are woman-like breast that, obviously, somehow got attached to the guy. This might be, in example, because said guy's hormones followed the general trend and got way out of the line in puberty. There is a rudimentary patch of real breast tissue in every male, but it starts to develop only if hormones tell it to. In such cases, they do and the unlucky dude ends up having breasts.
Or, simply, breast might just be another place where somebody's long term anti starvation investment, better known as excess fat, gets stored. Well, tough luck, some got it stored on their belly, some on their breast.
Can those breasts go away naturally?
In a majority of cases they can. Breasts are just fat, or fat/fibrous tissue mix. Melt the fat away, and breasts will disappear. The problem that baffles most people is that you can't target any specific area of fat with anything other than liposuction. Exercises are no exception. Fat gets evacuated evenly from all body regions, or might go away from one area sooner than other - again, not related with workout targeted at that area. But, if you keep on spending your fat deposits, there is no way that those breasts will remain. However, if you got stuck with actual gynecomastia, you will have to undergo surgery to remove breasts, or seek pill treatment.Natural way: the big picture
First thing to do is to alter your diet. True diet is not a "loose x lbs in y days" project that has a deadline (and which inevitably boomerangs on you as soon as it is over). It is a habit, a permanent change. Less or no material to build fat on means fat will go away whenever you need a little extra from your reserves and don't replenish them afterward.
Natural way: exercises
As we told, exercises melt fat away from all over the body. The more your metabolism is boosted, the faster the fat melts. This can be done with interval training - sudden alterations between moderate activity and all-out bursts. These bursts also cause your metabolism to burst, in order to keep up with sudden requirements for insane amounts of available energy.
Cardio exercises such as cycling and running are also great - they will push your body into a 'fat burning zone' metabolic mode for as long as you exercise. Sports are probably the best way to combine cardio and interval exercises. As for upper body workout exercises and push-ups: do not focus on them. As told, these will not burn fat away from breasts alone and may even emphasize their presence by pushing them out on a layer of muscle. However, firmed and toned upper body might make breasts blend in, so these exercises are not to be avoided.