CC Antya 8.67-68

nāty-aśnato ’pi yogo ’sti
na caikāntam anaśnataḥ
na cāti-svapna-śīlasya
jāgrato naiva cārjuna
yuktāhāra-vihārasya
yukta-ceṣṭasya karmasu
yukta-svapnāvabodhasya
yogo bhavati duḥkha-hā”
Synonyms: 
na — not; ati-aśnataḥ — of one who eats too much; api — certainly; yogaḥ — linking with the Supreme; asti — there is; na — not; ca — also; ekāntam — solely; anaśnataḥ — of one who abstains from eating; na — not; ca — also; ati-svapna-śīlasya — of one who dreams too much in sleep; jāgrataḥ — of one who keeps awake; na — not; eva — certainly; ca — also; arjuna — O Arjuna; yukta — as much as necessary; āhāra — eating; vihārasya — of one whose sense enjoyment; yukta — proper; ceṣṭasya — of one whose endeavor; karmasu — in executing duties; yukta — as much as necessary; svapna — dreaming while asleep; avabodhasya — of one whose keeping awake; yogaḥ — practice of yoga; bhavati — is; duḥkha- — diminishing sufferings.
Translation: 
“[Lord Kṛṣṇa said:] ‘My dear Arjuna, one cannot perform mystic yoga if he eats more than necessary or needlessly fasts, sleeps and dreams too much or does not sleep enough. One should eat and enjoy his senses as much as necessary, one should properly endeavor to execute his duties, and one should regulate his sleep and wakefulness. Thus one can become freed from material pains by executing mystic yoga.’ ”
Purport: 

This is a quotation from the Bhagavad-gītā (6.16-17).