The greasy, phlegmy feeling one experiences not while eating McDonalds, but immediately after finishing. Typically first noticed in the parking lot. Usually accompanied with mild nausea.
Walking out to my car, I noticed the McDonaldsPhlegm kicking in. Ghaack!
A certain period of time where a skinny and healthy person ignores all their sense of hygiene and become extremely obese and develop certain health problems.
Can also be a healthy person who actually goes into a McDonald's and eats there because when they walk out they have increased their risks of being unhealthy significantly.
Kaitlyn and Elliott used to be extremely athletic and healthy until they traveled through the McDonald's Time Machine and gained a combined 250 pounds and both developed heart disease and diabetes.