"Eating-related side effects are common during cancer treatment. Sometimes it’s the cancer itself that prevents you from eating well. But most of the time you may not eat well because cancer treatments can damage healthy cells along with cancer cells, causing side effects. It’s hard to predict how many side effects you’ll have or how strongly you’ll feel them. And when you have them, it can take some time to figure out what will help. You may find that your ability to eat well varies from one day to the next. This can all be pretty frustrating."