dietological

adjective

Pertaining to, derived from, or justified by dietology / the study of nutrition and nutritional regimes;  dietologically substantiated.

Examples: 

Suitability or unsuitability for certain dietological regimens has been inferred from generally known or publicly published findings in the literature and derived from the usual average nutritional composition.  (Source: J∙ Okram - Semolina Dumplings for Soups  ●  Cooking Recipe.)