According to Ayurveda, the concept of digestion depends on Agni, which literally means fire. In the lexicon of Ayurveda it actually refers to digestive fire. There are mainly four types of agni, Samagni which means regular or balanced digestive fire, Vishamagni or irregular digestive fire, Mandaagni which is dull or mild digestive fire and Thikshnaagni which is sharp and heavy digestive fire.

In Ayurveda, there are six types of taste, Madhur, which is sweet, composed of prithvi (earth) and jala (water), amla is sour composed of prithvi (earth) and tej (fire), lavan is salty, comprising of tej (fire) and jala (water), katu is pungent comprising of tej (fire) and vayu (air), tikta is bitter comprising of akash ( ether) and vayu ( air ) and kashay which is astringent , comprising of prthvi (earth) and vayu ( air ).

The rasa`s or tastes are present in all kinds of food. According to Ayurveda, the tastes can increase or decrease the three doshas namely Vata, Pitta and Kapha. The sweet taste or Madhur is known for increasing Kapha dosha. Amla or sour is known for elevating Pitta dosha. Lavan is known for increasing both Pitta and Kapha doshas. Katu or pungent is known for increasing Pitta and Tikta or bitter taste is known for accentuating Vata dosha. Kashay increases Vata dosha.

An Ayurvedic diet is complete only when a wide variety of food is consumed which balances the nutritive content required by the body. Any diet, which solely concentrates on one type of food, is incomplete as it is unable to balance all aspects of the physiology.