“You should 'feed a cold, starve a fever.'”

The old adage concerning how to approach illness, suggesting one should "feed a cold, starve a fever," has roots stretching back centuries. Its origins are often attributed to ancient Greek physician Hippocrates, who is believed to have thought that fever was a disease in itself and could be combated by denying the body food. This perspective evolved through the Middle (Review) Ages, where it was commonly believed that colds made the body literally colder, thus requiring food to generate warmth, while fevers, which made the body hot, necessitated fasting to cool it down. The phrase gained further traction after its inclusion in John Withals' 1574 dictionary, which stated that "fasting is a great remedie of feuer".

Despite its enduring presence in popular wisdom, modern medical science does not support this advice. In reality, whether you are experiencing a cold or a fever, your body's immune system requires sufficient energy and nutrients to effectively combat infection and facilitate recovery. A fever, in particular, increases your metabolic rate, causing your body to burn more calories as it works to fight off the illness. Therefore, depriving your body of food during a fever can actually hinder your recovery by denying it the crucial energy needed for its defense mechanisms.

The persistence of this misconception may be partly due to the common experience of a reduced appetite during illness. When the body is fighting an infection, the immune system releases chemical messengers called cytokines, which can signal the brain to suppress hunger, potentially to conserve energy for fighting pathogens rather than digestion. However, this natural decrease in appetite does not mean food should be withheld entirely. The most critical components for recovery from both colds and fevers are adequate hydration and gentle nutrition. Staying well-hydrated is paramount, as illness, especially fever, can lead to dehydration through increased sweating. Therefore, focusing on fluids and easily digestible, nutritious foods is key to supporting your body's healing process.