system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some people lose their appetite when they're upset or depressed, while others consume more food??

I'm the type that absolutely cannot eat when I am upset or depressed. I know this is common, but so is eating more when depressed. What determines how a person's hunger will be affected by their emotions?
gpt
People who eat more food when depressed generally do so because it's comforting to them (hence the name "comfort food"). Food high in carbs and sugar also help increase levels of serotonin in the brain (a neurotransmitter that elevates mood), thus helping to calm their nerves. So basically they use food as a drug to self-medicate their depression.

People who eat less food generally do so because they feel a lack of motivation or energy to eat food. Then there is also the fact that your stomach can have a hard time accepting food when you are extremely stressed (which is why some people throw up when stressed). Sometimes their bodies are just too riled up to be able to process food, so it doesn't seem as appealing.