Why does the body lose appetite when sick (like with the flu)? Shouldn’t it be super hungry as it needs more power to the immense system?

Question

*immune not immense

In: Biology

Answer 1

There are lots of reasons for changes in metabolism when you are sick.

* Increasing temp as part of immune response

* rapid increase in white blood cell production and other immune factors

* Body getting rid of stomach and bowel contents in case infected or poisoned food is an issue.

There are probably more as well.

Then there are the benefits of emptying the digestive tract (in case you have been wounded) to reduce sepsis (internal infection)

Then there is the benefit in a competitive environment of hiding away from predators (human and wild) when you are least able to protect yourself and most likely to be the part of the “herd” that is culled. If we feel sick we tend to hide in the cave.

Add to this that occasional fasting is good for us, so this is a perfect opportunity to reduce our food intake, and reduce the part of our metabolism involved in food gathering, consumption, digestion and elimination.