Meaning of liquid protein

liq'uid pro'tein

Pronunciation: [key]
— Nutrition. Nutrition.
  1. an amino acid hydrosol used in weight-reduction programs as a substitute for all or some meals: generally regarded as hazardous to health because of low nutritional content and recommended for controlled use only under medical supervision.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.