Weight loss may minimize the problem, but typically , men with gynecomastia may have to have surgery to reduce the size of your breast areas.  Get a consult and even a second opinion.  In the meantime - I'd simply "pristine my diet" meaning - lean, low fat protein choices (white, skinles meat, beans and legumes, fish, soy meats, eggs and egg whites, protein based pasta), whole grain/high fiber carbs - when making bread/cereal/rice/pasta choices (and besure you know portion sizes), go fat free on dairy and eat fruits and veggies.  Fats should be limited and come from the monounsaturated fat choices - olive oil, avocado, nuts - in very small portions.