During cancer treatment, there will come the time when eating food will become very difficult, and you will lose your appetite completely. This is when nutritional supplements come into play. You want a high protein drink with fiber to give your body something to live on. I suggest soups as a highly nutritious source of protein to help maintain muscle mass. Nutritional drinks like Boost and Ensure, while providing enough to get by,cannot replace the proteins like chicken, beef, vegetable soups provide. Protein, is the building block of recovery, and weight maintenance. And remember to hydrate well. Even if you have to force yourself.