I've had Parkinson's for almost 20 years. I am 64 years old. All of a sudden I started to lose weight rapidly. In the past year I've lost over 60 lbs. and I was 180 lbs. Why am I losing a lot of weight so fast with Parkinson's?. I've had tests and everything else checks out good. I drink a lot of protein drinks and try to eat a lot but I keep losing weight . What to do ?