Besides the fact that no one can ever remember which way round this old adage goes anyway, it sounds like hogwash of the highest order. But, you guessed it, it's not. Dutch scientists have evidence to suggest that starving and fasting could actually prompt two different kinds of immune response. It turns out that eating a meal tends to gear up the immune system to fight viruses, the usual cause of colds, but fasting is better for beating a bacterial infection likely to cause a fever. When test subjects were given food, it was observed that their levels of gamma interferon shot up by as much as 400%. This is indicative of the type of immunity needed to combat viral infections by tackling pathogens that have gotten inside the body's cells. When another group were given only water, gamma interferon levels dropped, but interleukin-4 levels shot up by another 400%. This is involved in the type of immunity that is most effective at combatting bacterial infections outside our cells. Whilst the study was pretty small, it does give you carte blanche to stuff your face next time you're feeling a little under the weather.
