Flat chest during puberty can continue to develop in some girls and does not need to be remedied. If necessary, flat chest can be improved through dietary modification, exercise and other methods. 1. Do not need to remedy: puberty is still a developmental stage of the body, the general girl in about 12 years old breasts began to develop, will continue to 18 years old or so. If you are not yet 18 years old, your breasts will continue to develop and you do not need any special treatment or remedy. 2. Dietary adjustments: If the girl’s flat chest is more serious, or the girl herself is thin, it may be due to malnutrition during puberty. At this time you need to eat collagen, carbohydrates, fat, protein high food, such as a variety of meat, eggs, dairy, pig’s feet, etc., so as not to affect the normal breast development. 3. Exercise: usually, you can also actively strengthen the chest muscle exercise, such as doing chest expansion exercise or push-ups, can increase the thickness of the subcutaneous muscles of the chest, to improve the chest shape. It is recommended that the girl go to the regular hospital in time, if necessary, under the guidance of the doctor to carry out the corresponding conditioning treatment.