Have you been checked for hyperthyroid? When I was diagn. I was probably 15 pounds underweight and did not have any other symptoms.
All I can say is, I wish I had this problem, especially if you are not ill. I swear I just look at food, and on goes a kilo or two. I put on 20 kilos in the 9 years since having my uterus removed, and have just recently had my ovaries removed, so I'm hoping it doesn't cause any more weight gain. Keep up your healthy diet, but maybe you can allow yourself a few more of lifes (fattening) little luxuries. Have some for me while you're at it.