A tiny and largely misinterpreted study in 2002 recently fanned the flames of this myth, but limiting your caloric consumption may actually hurt your immune system more than helping it — it would certainly be a bad idea to not eat during the six- to eight-day duration of a cold.

Instead, doctors say to go ahead and eat if you can. The more accurate expression would be "feed a cold, feed a fever." And make sure to drink plenty of fluids.