Is viral infection severity is linked to undernourishment as well as over-nourishment?

Answer 1

Over-nourishment is generally associated with fewer and less severe side effects of viral infection, as the body is better able to mount an effective immune response. Undernourishment, in contrast, is generally associated with greater and more severe side effects because the body's immune response is inadequate due to lack of nutrient reserves.

Answer 2

In general, malnutrition or undernourishment is associated with increased severity of viral (and bacterial, fungal and other) infections. However, except for a few specific cases, over-nourishment generally has little to no effect on viral infection severity as compared to adequate nourishment.