threpso-, threps- (Greek: nutrition, nourishment).
athrepsy, athrepsia, athreptic:
1. Lacking nourishment.
2. Known as marasmus: Emaciation and wasting in an infant due to malnutrition.
3. In medicine, immunity to tumor inoculation due to a supposed lack of the special nutritive material necessary for tumor growth.
The sum of what is known concerning nutrition; the science of nutrition.