The Compendium of Caraka 3.6.13

3.6.13

tatra kecidāhuḥ---na samavātapittaśleṣmāṇo jantavaḥ santi, viṣamāhāropayogitvānmanuṣyāṇāṃ; tasmācca vātaprakṛtayaḥ kecit, kecit pittaprakṛtayaḥ, kecit punaḥ śleṣmaprakṛtayo bhavantīti/

Here, some say: 'There are no living beings whose vāta, pitta, and kapha are in balance, because humans use irregular diets; therefore, some have a vāta constitution, some a pitta constitution, and some a kapha constitution.'