I am 17 and doing the Master Cleanse. How will I get my everyday proteins? HELP! URGENT!?

This is my first day of the Master Cleanse. I am not hungry or anything YET. But, my friend told me that I would not be able to survive without any proteins for another seven days. I am not sure if she is right. Any suggestions? Should I continue my cleanse? My BMI is 26.0 and I need to lose 10lbs approx to get to the normal BMI. HELP!!!