UPAVĀSA Upavāsa means going back from sin and leading a good life. (Upā (varta) = go back and Vāsa = A life). All actions which are not good, must be relinquished. Those who observe Upavāsa should abstain from using flesh, Masūra (pulse), caṇaka (a kind of gram), Varaku (a kind of grain), green leaves prepared), honey, rice etc. and from contact with women. He should not wear flowers, ornaments, or fashionable dress; should not inhale fragrant smoke, and fragrance of any sort. Cleaning the teeth and using collyrium also are prohibited. Instead of cleaning the teeth in the morning Pañcagavya (Milk, curd, ghee, urine and dung of cow) should be taken in. Drinking water several times, using betel leaves, sleeping in the day time and sexual act also should be avoided.
[Agni Purāṇa, Chapter 175] .