Is the saying 'starve a fever and feed a cold' true?
It is a misunderstanding that most assume this refers to eating
and/or drinking. In actuality this phrase concerns
To 'Starve a Cold' means to get away from the most common cause
of colds, cold weather, and stay warm. To 'Feed a Fever' you are
trying to break the fever into a sweat, by getting warmer.
The correct term is "Starve a Cold, Feed a Fever" and it means
the same thing in both cases, bundle up and stay warm.
Another take, based on known fact, is that temporarily avoiding
food improves immune response. A fever is part of how the body
fights infection. It is thought that loss of appetite is in this
way part of the body's natural infection-fighting process. So the
best advice is indeed to avoid eating temporarily when one has a
fever and a loss of appetite. A cold in contrast typically has no
fever, and appetite is not diminished.