One of the side effects of prednisone is increased appetite. Be careful that you don't just give in though. I gained 24 pounds while on prednisone which is okay if you have a huge weight loss to begin with but it isn't really healthy weight in my opinion. I was on prednisone for 7 months the first time, off for nine months, and am now back on it, going on month 2........I am watching my caloric intake very carefully, still eating healthy, exercising and I am still seeing the scale increase.
With that being said, increased appetite and weight gain are two of the LEAST horrible side effects of this drug.
Good luck.