Can you tell me what is diet and exercise to reduce the gynecomastia! (man boobs)?

Certainly, a good...: Diet and being at or near your ideal weight can help, but true gynecomastia is not dependent on or correctable with diet and exercise. The operations used are very effective. See a surgeon certified by the american board of plastic surgery to evaluate your options. Good luck.

Depends on the cause: Are you overweight? This condition can arise on its own or can be secondary to certain drugs (ie marijuana and many prescription meds) and also can be secondary to hormonal problems that may signal a bigger issue. If you aren't simply overweight consider seeing your md. You need a testicular exam, review of your medications, and several blood tests that are not part of routine bloodwork.

No magic diet: Unfortunately there is no magic diet to reduce gynecomastia. There are some plant like substances that may have estrogen like effects that should be avoided and include marijuana. It used to be thought that soy based phytoestrogens may have been responsible for gymecomastia exacerbation and that these products should be avoided but that has been essentially disproved.