We have observed that Prakrti or the Prakrtic energy of the Heart may be identified with Food, conceived in its widest sense. Now the problem of the human Heart, in its physical aspect, may be examined from three points of view. It is connected with Prana or breath; it is dark in form; and it is connected with blood, formed out of food, out of which is produced all vital energy of the body. All these ideas are associated with Prakrti in the Sankhya system. It is described as Tamas or Darkness, because of the colour of the Heart; it is called Water or a liquid in respect of its blood and vital energy; and it is associated with breath or Prana, as the energy of physical action.
Food, as we have observed, constitutes the physical vital energy of all animals. All live by food; and it is the vital seed, itself formed out of food, that makes the embryo from which all creatures are born. It is for this reason that it is said that all creatures are produced by food; and that from food are born all creatures that live on Earth; afterwards they live on Earth, and in the end (when they die) they return to it.
Food, Prakrti, Earth: We have explained that Food may be identified with the Prakrtic (physical) energy of the Heart, and so identified with Prakti; and it is for this reason that it is said that "what is food is Pradhana (Prakrti)", and that "Purusha is the eater, Prakrti, the food".
Hence Man is said to consist of food. Again we have explained that our planet Earth may be identified with Prakrti; and so the Earth is identified with food. Indeed, as we know, it is the Earth that supports all life made manifest on it. Some animals live, on others, but the ultimate support of all is the vegetable kingdom, born of the Earth. Hence the Earth is the mother of both the vegetable and animal kingdoms, and is so regarded in all Sacred Books of the Hindus.
Thus we see that Food is identified, with Prakrti; and as the problem of Prakrti is associated with all systems of Hindu Philosophy, we should be able to find support for this view in the Upanishads.
Food in Vedanta: Vedanta deals with Prana or breath in its twofold character; in respect of action conceived as a Sacrifice, and as a vehicle of the Self or the Soul and so Food and Prana are said to be two gods, and food is grasped and swallowed by breath, the vehicle of the Highest and the process of eating or the action of food and its eater is spoken of as self-sacrifice.
Food in Yoga: Yoga deals with food in the light of Buddhi, Sun-energy, heat, or the power of thought and so it is said that food is produced by repeated that Brahman produces it by means of Tapas (heat); and that the Sun is the final cause of food.
Food in the Vaisesika: The Vaisesika examines the problem of food in the light of the energy of the Mind; and, as the Moon symbolizes the Mind, and food is ultimately based on the vegetable kingdom, the Moon is spoken of as the nourisher of the vegetable kingdom in the Bhagavad Gita, while in the Satapatha Brahmana the Moon is identified with food.
In the Upanishads we are told that food, when eaten, becomes threefold, and its subtlest portion becomes the Mind.
Food in Nyaya: Nyaya deals with the problem of food in the light of the senses of knowledge; and, as the latter are a part of the physical body, it may be said to examine it in the light of the body itself. In this respect there is not much difference between the Nyaya and Sankhya points of view; for the latter considers food in the light of the senses of action, and they, like the senses of knowledge, are equally a part of the body. In connection with both the Nyaya and Sankhya we have, therefore, to consider the problem of food in the light of our body. In this connection we must observe, however, that the idea of Sacrifice is closely associated with the system of Nyaya, while it is lacking in the Sankhya; and food forms part of Sacrifice in all sacred works of the Hindus. The real idea of Sacrifice in this connection consists in moderation in taking food, making for control of the senses of knowledge; but, even in its more popular conception, no act of sacrifice is said to be complete without offering food to Brahmanas and others deemed worthy of it. This is the difference between the Nyaya and Sankhya ideas relating to food.
Food in the Sankhya: We have explained how the problem of food is vital to the Sankhya system, for both of them refer to the Prakrtic (physical) energy of the Heart, identified with Prakrti. In this connection we have already explained the connection between food, Prakti and our planet Earth, and shown how they may all be identified.
Food and Water: As we have explained, Water is Prakrti; and we have further to examine food in connection with Water in the Sankhya system and so we are told that Water is the origin of food; and that the Purusha, "brooded over Water, and from Water, thus brooded on, matter (murti) was born and this matter verily was food".