Thyroid issues can make you gain weight more easily than you would normally, but I have co-workers that have thyroid issues, both actually had the same type of thyroid cancer. One weighs about 330 and the other weighs about 140-150... I bet you can't guess which one runs 10 miles a day and does her best to compensate for her issues? ;) When the runner broke her ankle she ballooned up to 250ish but she ran it all back off again. no excuses.