“The five-second rule probably should become the zero-second rule,” said Dr. Roy M. Gulick, chief of the division of infectious diseases at Weill Cornell Medical College. “Eating dropped food poses a risk for ingestion of bacteria and subsequent gastrointestinal disease, and the time the food sits on the floor does not change the risk.”

Quote and illustration from Q&A: You know the five-second rule for dropped food? Is it really safe if you pick it up in time?