As you probably know, there are two basic kinds of moob or 'man-breasts' as they are familiarly known.
The minority of men suffering from moobs have a condition with the formal medical name of 'gynecomastia' (which means, literally, 'womanly chest'). This means that the chest-tissue under and around their nipples puffs and develops like women's breasts. It usually affects men in their teens to early twenties, or much older men. Men in their twenties up to their sixties are quite unlikely to suffer from gynecomastia unless they are taking certain chemicals such as steroids or marijuana. This is because gynecomastia is caused by changes in hormone levels that usually only happen in youth and age.
The other kind of moob or man-boob is development of the fatty tissue in the chest, ie 'fat padding' in the fat cells there. On a woman, the breasts are formed of fat and glandular tissue. This female glandular tissue is what swells up in pregnancy in order to produce milk for the baby. In men, there is no equivalent milk-production function for the chest tissue. So, the vast majority of moobs are composed of plain and simple fat cells that have got well padded with dietary fat.
Why does the male chest develop this fatty tissue? Well, the short and simple answer is that if your chest has developed some 'hanging fat' in the form of moobs, it is extremely likely, in fact almost certain, that you have excess fat elsewhere on the body too. Most likely it will be visible around your waist and belly as 'love-handles' or an 'overhang' when you wear jeans. However, when a man puts on weight, a lot of fat accumulates inside the body as well, around vital organs such as the heart, liver and kidneys, where it can have an adverse effect on energy levels and health. This is part of the reason why staying reasonably slim and fit is an important part of staying healthy and staying alive.
The way both men and women get fat is that they eat more calories than their body can use. These calories come from all kinds of food in the diet, but the most fat-forming foods are oils, fats, refined carbohydrates and sugars. The excess calories are converted into fat and the fat is stored in the fat cells of the body. So the fat cells get bigger and bigger the more excess calories are eaten. That's what swells up the belly and chest.
Men have a majority of fat cells around the waist and chest, where women tend to carry fat on the hips, breasts and under their skin all over the body. So, men, when you put on weight you are definitely running the risk of developing a more 'feminine' figure.
The best way to get rid of moobs is, then, obviously, to lose weight off your whole body. Unfortunately there is no way of 'spot-reducing' fat from the chest except by liposuction. There are various risks and problems associated with surgery for moobs - not least of which is that it does nothing to correct the overall weight problem which is a health risk.
