"Man boobs" are fat deposits on the chest and on top of the pectoral muscles. In most men, these fat deposits are caused by obesity and are a sign of excess fat on other parts of the body. It is not possible to turn these fat deposits into muscle tissue, but you can get rid of the fat to reveal the pectoral muscles underneath. The best way to remove excess fat and build muscle is through diet and exercise.
Eat whole grains, fruits and vegetables. In addition to being nutritionally dense and relatively low in calories, these foods also provide dietary fibre. Dietary fibre makes you feel full faster and longer and keeps the digestive tract running smoothly.
Eat lean protein. You body needs protein to build muscle, but a lot of proteins are also loaded with saturated fats. Stick to leaner proteins like chicken breast and egg whites.
Avoid white carbs. Your body needs carbohydrates for energy, but not all carbs are created equal. Processed, enriched grain products and refined sugars have very little fibre or nutritional value. Go for the whole wheat and whole grain products.
Check the ingredient list. Manufacturers list ingredients from those that make up most of the food to those that make up the least. If salt, fat, sugar or some unrecognisable chemical are in the first five ingredients, that food is probably not healthy.
Watch portion size. It is very easy to undo all of your hard work simply by eating too much -- no matter how good it is for you.
Exercise the whole body. It is not possible to spot-reduce -- to lose fat in your chest, you have to lose fat all over your body.
Do cardiovascular exercise. Do some kind of continuous activity for at least 30 minutes a day, five days a week. Try an aerobics class or go for a brisk walk outside or around the mall.
Break a sweat. Moving is just the beginning, you also need to get your heart rate high enough to break a sweat and burn calories. You should be breathing heavily, but not gasping.
Lift weights. Pectoral flys, chest presses and push-ups all work the pectoral muscles. These exercises won't burn fat in the chest, but they will sculpt and shape the pecs so that they look better when the fat is gone.
The USDA food guide pyramid is an excellent source of information for healthy food options and proper portion sizes.
Always consult your physician before embarking on any diet or exercise program.