What should I eat during treatment?

I'm wondering if the green tea you drink is matcha? Or just green tea bags? I have heard that caffeine is not recommended during treatment. My doc says to eat whatever I want but stay away from spicy foods. I have also read that only eat white foods, rice etc. I'm so confused and what to eat and not eat. I am done with one week out of 5.5 weeks of treatment and I have absolutely no side effects....yet. I have been growing broccoli sprouts in jars. I ate about one cup every day until the PA I saw said broccoli (including sprouts) will make it hard to have a good bowel movement down the road. If I blend it up in a smoothy and drink it I'm thinking that might be ok. My onc did advise me to stop taking Vit D3 while on chemo so I stopped for now. Thanks!