One possible symptom of hyperthyroidism is loss of appetite. Other symptoms can include weight loss and fatigue. Although you eat healthy, apparently your body isn't getting enough nourishment. In my opinion, the logical thing would be to find out WHY you have no desire to eat and to be safe get checked out. It may be that there is no medical explanation. Even if there is only a 1% chance that there is, at least you know. 1% (although I don't understand how it got to this) is still a chance.