During cancer treatment, you might need to change your diet to help build up strength and withstand the effects of the treatment. This may mean eating things that aren’t normally recommended when in good health. For instance, you might need high-fat, high-calorie foods to keep up the weight, or thick, cool foods like ice cream or milk shakes due to sores in the mouth and throat that make it hard to eat anything. The type of cancer, ongoing treatment, and side-effects of the treatment must be considered when trying to figure out the best ways to get the nutrition your body needs.