I went along doing the one-salad-a-night routine for a year. And I remember feeling so tired and depressed and irritable. I had no personal life. I was always flying someplace - weekends, holidays, vacations. Dinners at night were no fun because I couldn't eat.
The knowledge that there is a part of the psychic functions that are out of conscious reach, we did not need to wait for Freud to know this!