In Krishna conciousness nothing is prohibited, but everything is made yukta, regulated.
One has to observe the prescribed rules and regulations, as confirmed in Bhagavad-gita, yuktahara-viharasya. When one engages in devotional service in Krishna consciousness, he still has to eat, sleep, defend and mate because these are necessities of the body. But he performs such activities in a regulated way. He has to eat Krishna-Prasada. He has to sleep according to regulated principles. The principle is to reduce the duration of sleep and to reduce eating, taking only what is needed to keep the body fit. In short, the goal is spiritual advancement, not sense gratification. Similarly, sex life must be reduced. Sex life is meant only for begetting Krishna conscious children. Otherwise, there is no necessity for sex life. Nothing is prohibited, but everything is made yukta, regulated, with the higher purpose always in mind. By following all these rules and regulations of living, one becomes purified, and all misconceptions due to ignorance become nil. It is specifically mentioned here that the causes of material entanglement are completely vanquished.
The Sanskrit statement anartha-nivrtti indicates that this body is unwanted. We are spirit soul, and there was never any need of this material body. But because we wanted to enjoy the material body, we have this body, through the material energy, under the direction of the Supreme Personality of Godhead. As soon as we are re-established in our original position of servitorship to the Supreme Lord, we begin to forget the necessities of the body, and at last, we forget the body.
Sometimes in a dream, we get a particular type of body with which to work in the dream. I may dream that I am flying in the sky or that I have gone into the forest or some unknown place. But as soon as I am awake I forget all these bodies. Similarly, when one is Krishna conscious, fully devoted, he forgets all his changes of body. We are always changing bodies, beginning at birth from the womb of our mother. But when we are awakened to Krishna consciousness, we forget all these bodies. The bodily necessities become secondary, for the primary necessity is the engagement of the soul in real, spiritual life. The activities of devotional service in full Krishna consciousness are the cause of our being situated in transcendence. The words bhagavaty atma-samsraye denote the Personality of Godhead as the Supreme Soul or the soul of everyone. In Bhagavad-gita Krishna says, bijam mam sarva-bhutanam: “I am the seed of all entities.” By taking shelter of the Supreme Being by the process of devotional service, one becomes fully situated in the concept of the Personality of Godhead. As described by Kapila, mad-guna-sruti-matrena: one who is fully Krishna conscious, situated in the personality of Godhead, is immediately saturated with love of God as soon as he hears about the transcendental qualities of the Lord.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Third Canto, Chapter 33 – Text 26
