Breast size is related to genetic factors in the family, and also related to estrogen and dietary habits during puberty. Breast size will be affected by heredity, generally the chance of heredity is up to 50%-60%, inborn genetic factors can not be changed, the patient can also make up for it through later life. Breast development will be affected by the hormone secretion in the body. Prolactin secreted by the pituitary gland can enlarge the breast glands; estrogen secreted by the ovaries can promote breast development. Therefore, during pubertal breast development, you can eat more soy milk, honey and other foods high in estrogen, which are good for ovarian function and can better promote breast development. It is important to maintain good living habits and strengthen physical exercise, but if you pass puberty, the effect of diet on breast size is minimal.