Juice cleanse

So I decided to start a juice cleanse! I'm almost done day one and my head is killing me.  I read online this is due to caffeine withdrawals which I believe because I love my coffee and coke zero.   Surprisingly I don't feel that hungry though....yet haha.  I am just doing it for three days to try it out and next time I will go for longer.  I am drinking happy planet and bolthouse farms juice.  I may try making my own tomorrow I found some great sounding recipes and need to take in more calories than I did today.  Hopefully I can keep the cravings away!!
Calories yesterday - 1325
Calories today - 691