My husband asked me if I should be starving or feeding my illness. "Starve a cold, feed a fever? Feed a fever, starve a cold?" Though he couldn't remember this old axiom, it is "starve a fever, feed a cold."
So, is there any truth to it? Maybe. When you have a fever, your body is working hard to fight an infection. Digesting a full meal may be challenging at that time. Does that mean you should fast completely? Not for long periods of time, but you can ease the challenge on your digestion by consuming primarily liquids, such as water, herbal tea, fresh juices, green juices, smoothies and broths. Bieler broth is a good option.
What about feeding a cold? Common colds tend to last longer than fevers and it's important to keep up one's strength. Eating somewhat simply is still important. All the liquid options mentioned above are still good choices, but you can add some solid high nutrient foods, like fresh vegetables and lean protein sources.
Important things to avoid include sugar and dairy. Sugar is the prefered fuel source for viruses and bacteria and directly depresses the immune system so it's the worst food you could choose when you are unwell. Dairy is highly allergenic, inflammatory and mucus producing (this is controversial, but for me it's definitely true) so it's also something to avoid while you are ill. When you are unwell, you should also avoid any known food allergens and highly processed foods - keep it simple.