malnourished

Definition of malnutrition
National Cancer Institute

malnutrition

(mal-noo-TRIH-shun)
A condition caused by not getting enough calories or the right amount of key nutrients, such as vitamins and minerals, that are needed for health. Malnutrition may occur when there is a lack of nutrients in the diet or when the body cannot absorb nutrients from food. Cancer and cancer treatment may cause malnutrition.

Source: NCI Dictionary of Cancer Terms