I have been somewhat lucky in the respect that I don't get physically sick too many times but it will come on anytime, anywhere for no reason. If I am home and I lay down for 20 to 30 minutes and just rest it seems to subside a good deal. The smell of food sometimes will trigger it. It took them 3 years to finally diagnose mac in which I lost 100 lbs. I have to take vitamin B12 shots and have since gained 10 lbs. I didn't know the shots could bring back my appetite.