Those patients who lose their appetite are likely to lose weight - but the same can be true even if a high calorie diet is being eaten, due to changes in the body.
That's because cancers can produce molecules that change the way the body functions.
For example, cytokines are proteins normally produced by the immune system to help your body fight infections. Cancers are known to produce these in large numbers. This abnormal release leads can cause weight loss by making the body break down proteins and fat.
High energy foods can help people to maintain their weight