Forum:Weight Problems

I'm wondering if anybody else has encountered the problem I have. I created an overweight Sim for story purposes. I thought it would be interesting to start out of shape and then as she progressed in the film career shed the pounds and become a famous actress (I gave her the athletic trait). But now that I've done that, she becomes fat at the drop of a hat. The most important thing I noticed - I had her working out for 10 HOURS STRAIGHT - and she weighed more at the end than she did when she started. Has anybody had this problem? It's getting annoying.