Many people with cancer find that there are times when they can’t eat as much as usual, and sometimes they lose weight. There are lots of reasons for this: it can be related to the cancer itself, or to the side effects of different treatments. Some people find that they don’t feel hungry, or that they feel full soon after starting a meal. Other people find that food makes them feel sick (nausea), or that their treatment makes some foods taste different. Some types of cancer make your body use up more energy, even if you’re not very active. This can make you lose weight, even though you may still be eating well.