Almost everybody. When you would like to say "everybody" but you know exactly some jerk will pipe up "not me" then you use "manybody." For example, manybody celebrates Halloween.
Manybody watched the Superbowl.
The opposite of health food. You go to a "green" market for health food, and you go to a burger joint for food that is guaranteed to raise your cholesterol level to the top of the Empire State Building and load you up with a week's worth of sodium.
Yesterday I overdosed on unhealth food at the local burger place.