I had lost a lot of weight after the diagnosis and surgery, so no, no fasting or dieting. I ate what I wanted. My daughter, who is very health and diet conscious, suggested an organic, plant based diet which I do to this day (especially for milk, because 1% milk is my favorite beverage). Here's something else, after the chemo, I would get like this lump in my throat. It would go away, and I felt better after eating! (pretty antithetical). Even on the organ bench, I'd have a bunch of grapes and saltines at the ready. That sensation lasted during the whole chemo time. I didn't play with supplements--too afraid it would disrupt the chemo. Your doctor will let you know if you need anything in that regard. They served lunch in the chemo room. Who would think you'd look forward to that? but I did! Looking back eating was my best ally. There are all kinds of cookbooks for this period of time.