When it comes to fighting off the myriad cold and flu bugs floating around your home and office (and generally everywhere else you go right now), prevention isn’t just about what you do eat. There are a few things to avoid when you feel like you might be getting sick or to avoid catching your husband’s or kids' colds altogether. The first culprit: sugar. “People get sick right after Halloween because we eat so much sugar,” says Pomroy. “Sugar cuts the immune system and puts you at risk for getting sick. It suppresses immune response in blood,” she explains.