6. Low Mood - If you experience it will most likely be felt on day 2, but my misery passed pretty quickly. The cause due to chemical changes in the brain. According to Livestrong anxiety, irritability and depression are common emotional disturbances of a detox diet. A true fast brings up more negative emotions than does a more balanced 7-day detox diet. If you are feeling blue, journal your emotions with your foods in your journal.