As I’ve been suffering from a bad cold for almost a week now, and spending waaaay too much time bundled up in bed, I figured now was as good a time as any to examine the old adage “feed a cold, starve a fever” and see if there was any truth to it. First off, I want to say that dietitians never recommend “starving” for any reason, so you can rest-assured I won’t be giving anyone that advice. But what’s this bit of medical folklore all about?
It’s thought that “back in the day,” people noticed that eating generates heat in the body (it raises metabolism), which would help one feel warmer during a cold, while the converse—abstaining from food—during a fever would help cool the body. I can see how, back in the day, this made sense, but of course we know now that colds are not caused by being chilled, but by viruses. But let’s take a look to see if there is any science to back up the notion that we should modify our food intake during the two types of illnesses.
What does the science say?
A study published in 2016, done with mice that were infected with either a flu virus or a food poisoning bacteria found that all the mice naturally ate less after becoming ill. However, the researchers had force fed some of the bacteria-infected mice, and the same with the some of the mice that had the viral illness. After ten days they found that, for those mice with the viral infection, force feeding was protective—but not so with the bacteria-infected mice. Interesting! Of course, humans are not mice. A small amount of human research has been done. Some of it indicates that fasting may help the body fight some types of illnesses such as flu, while eating a nutritious diet might be helpful in fighting certain other types of infections such as those that typically cause colds. Indeed, both approaches appear to stimulate immunity in some way. However, fevers can be caused by both bacterial and viral infections. And colds are caused by over 200 different viruses (although half of them are caused by rhinovirus). So, what to do?
What to eat if you’re sick?
If you have a cold or the flu, a fever or no fever, staying hydrated is important no matter if you have a fever or not, as it helps the body fight illness and replace fluid losses. Water should be your primary drink, but a little juice is okay too. Sports beverages likely aren’t necessary (especially if you are not vomiting) but they are also unlikely to harm. Even milk works, and by the way, research shows that consuming dairy during a cold does not increase mucus secretions, so if you want a glass of milk, go ahead and have it. Warm beverages like tea and soups (chicken soup, if you like) may feel good to you and are shown to help alleviate congestion and a sore throat. And spicy foods may help open up a stuffy nose.
As for food, eat if you’re hungry, but don’t force-feed yourself. When you choose to eat, make it something nourishing that will provide energy from carbohydrates as well as vitamins and minerals from fruits and vegetables. A few ideas that might appeal: oatmeal topped with fruit, soup (preferably lower sodium soup) and whole grain crackers, pasta with marinara sauce, or a bowl of rice or quinoa mixed with steamed vegetables, for example. If you don’t have much appetite but just need a little snack, consider something like whole grain toast topped with peanut butter and/or applesauce, or a cup of Greek yogurt. Here are a few more ideas from a previous post on feeding a sick family.
If your body gives you the hunger cues, go ahead and follow them, choosing nourishing foods, not empty-calorie snack foods. And no matter what, do stay hydrated. And of course, see your physician if you have unusual symptoms, a high fever or experience an extended period of illness. For sick infants and children, seek medical advice from their pediatrician’s office.