Polycystic Ovarian Syndrome, where in due to hormonal irregularities the person has symptoms of irregular menstruation, weight gain, insulin resistance (diabetes) and excess
androgenic activity causing facial hair. Again symptoms of weight gain could all be the side effects of certain medications. It could also be due to hypothyroidism, it also causes constipation, weight gain and loss of appetite, it could be in the subclinical form, when it fails to manifest.