I would not recommend that you make any kind of drastic change to your diet at the same time or close to the time that you transition to polyphasic sleep. I have attempted to adjust to the schedule two times at this point. The second time, I switched to a raw diet because I heard that sleep requirements are reduced. I didn't realize that doing that would also send my body into a detox, which resulted in too much happening to my body all at once.
Kirk’s Blog » Too Much Too Fast
Also, just a warning that most people don't adjust the first time, but it's good that you have a lot of time without obligations. There are plenty of stupid mistakes that people have made. One thing that you will likely have to learn is how to fall asleep quickly for the naps. Many people find it hard to stop oversleeping at night, and this in turn leads to difficulty in falling asleep during the day. Napping is really an art that you will have to master before you will adjust.
Kirk’s Blog » How to Fall Asleep Immediately
~Kirk