So is a poster named "Heisenberg":
http://www.freerepublic.com/focus/news/1350945/reply?c=22
This isn't quite accurate. In 1992 a jury of twelve Floridians hearing the law suit of The Schiavo's detailed the long history of dieting, binging and purging. This was attested to by her parents during the trial and supporting evidence from her admission to the the ER on the night of her cardiac arrest. She was severely hypokalemic(low potassium) which is a clinical sign of people with eating disorders like bulimia.
Is it possible to inject a person with a chemical that would be undetected but would cause a low potassium level? Tin foil hat off....