"When [the body] is worn down and exhausted by hunger and thirst, the mind in its turn must feel the strain, that mental organ which must reap the fruit. No, inward calm is needed for success! Inward calm cannot be maintained unless physical strength is constantly and intelligently replenished. Only if the body is reasonably nourished can undue strain on the mind be avoided"
"Buddhist Sciptures" by Edward Conze p46
Quotes text from "Buddhacarita" by Ashvaghosha, vi 14-8,21-2,43-52