With aging, the rate at which men burn calories declines and they tend to lose muscle, with the muscle being replaced by fatty tissue. This excess fat puts men at a greater risk for a myriad of weight-related conditions, including the development of a condition called gynecomastia or, simply put, man breasts. Considered a negative feature, man breasts may cause psychological and social effects leading to embarrassment, fear and shame, causing men to avoid activities that may involve removing the shirt. Actually, the development of breasts in men is quite common, with up to 30% of adult males suffering from this embarrassing condition. Although the development of man breasts can be the result of a hormonal imbalance, the most common cause is obesity and excess weight resulting in excess fat being deposited in the chest area.