I would honestly go to your doctor and talk about it. Something else could be going on. I've never heard of anything, but it's possible the "full" receptors in your stomach could be misfiring. I say that in all seriousness! You could have an obstruction of some sort.
Are you on any medications? If so, check the side effects. A lot of meds can have loss of appetite as a side effect. If you're reacting to a medication, you should get your doctor to lower the dosage or try something else.