system
Given the following post, respond as if you're commenting on Reddit:
human
Why do people with cancer suffer from increased weight loss?
gpt
* Tumor scells eat up a lot of calories since they grow uncontrollably. 
* Decreased appetite because pain/nausea. 
* All the "good for cancer" meals are also just healthy in general. as is most "good for cancer" behaviours like sleep and exercise.